METHYLHYDRAZINE
CASRN: 60-34-4
See Occupational Exposure Standards

Human Health Effects:

Evidence for Carcinogenicity:

A3; Confirmed animal carcinogen with unknown relevance to humans.
[American Conference of Governmental Industrial Hygienists. TLVs & BEIs: Threshold limit Values for Chemical Substances and Physical Agents andBiological Exposure Indices for 2002. Cincinnati, OH. 2002. 42]**QC REVIEWED**

Human Toxicity Excerpts:

METHYLHYDRAZINE IS STRONGEST CONVULSANT & MOST TOXIC OF METHYL /SUBSTITUTED HYDRAZINE/ DERIVATIVES.
[Clayton, G. D. and F. E. Clayton (eds.). Patty's Industrial Hygiene and Toxicology: Volume 2A, 2B, 2C: Toxicology. 3rd ed. New York: John Wiley Sons, 1981-1982. 2292]**PEER REVIEWED**

MONOMETHYLHYDRAZINE IS A STRONG METHEMOGLOBIN FORMER & BLOOD PIGMENTS ARE EXCRETED IN URINE. LIVER CHANGES ARE PRIMARILY OF FATTY DEGENERATION TYPE, SELDOM PROGRESSING TO NECROSIS ... MONOMETHYLHYDRAZINE ... IN HIGH DOSES CAN CAUSE EXTENSIVE KIDNEY DAMAGE. CHANGES IN HEART MUSCLE ARE PRIMARILY OF FATTY CHARACTER. NAUSEA OBSERVED WITH ALL ... HYDRAZINES IS OF CENTRAL ORIGIN & REFRACTORY TO MEDICATION.
[International Labour Office. Encyclopedia of Occupational Health and Safety. Vols. I&II. Geneva, Switzerland: International Labour Office, 1983. 1069]**PEER REVIEWED**

... A GROUP OF MALE VOLUNTEERS WERE EXPOSED (HEAD ONLY) TO 90 PPM ... FOR 10 MIN TO EVALUATE EMERGENCY EXPOSURE LIMIT (EEL). ... THERE WAS SOME EYE REDNESS & SLIGHT TICKLING SENSATION OF THE NOSE. ... THE ONLY HEMATOLOGIC ABNORMALITY WAS HEINZ BODY FORMATION IN 3-5% OF ERYTHROCYTES BY SEVENTH DAY POST-EXPOSURE ...
[Clayton, G. D. and F. E. Clayton (eds.). Patty's Industrial Hygiene and Toxicology: Volume 2A, 2B, 2C: Toxicology. 3rd ed. New York: John Wiley Sons, 1981-1982. 2801]**PEER REVIEWED**

Mushrooms inducing headache about 6 hr after ingestion: This intoxication is assoc most often with Gyromitra exculenta, which may be mistaken for the edible morel. ... The toxin is monomethylhydrazine, which antagonizes pyridoxine. The toxin is volatile, & the mushroom may be made edible by air drying or by extraction of the toxin with boiling water, which is then discarded.
[Gosselin, R.E., R.P. Smith, H.C. Hodge. Clinical Toxicology of Commercial Products. 5th ed. Baltimore: Williams and Wilkins, 1984.,p. III-295]**PEER REVIEWED**

Onset of symptoms /from monomethylhydrazine produced in mushrooms/ is sudden, usually about 6 to 8 hr after ingestion or inhalation of vapor from cooking mushrooms. It is characterized by headache, malaise, abdominal fullness, & emesis (but not diarrhea). Generally, the patient recovers completely within 2 to 6 days. However, fatal hepatic necrosis has developed.
[Doull, J., C.D.Klassen, and M.D. Amdur (eds.). Casarett and Doull's Toxicology. 3rd ed., New York: Macmillan Co., Inc., 1986. 764]**PEER REVIEWED**

Severe health hazard. May be fatal if absorbed through skin or inhaled. Strong sensitizer. Corrosive. Causes severe eye & skin burns. Symptoms of overexposure include convulsions, damage to liver & kidneys, death.
[Fire Protection Guide to Hazardous Materials. 12 ed. Quincy, MA: National Fire Protection Association, 1997.,p. 49-89]**QC REVIEWED**

Liquid will burn skin & eyes.
[U.S. Coast Guard, Department of Transportation. CHRIS - Hazardous Chemical Data. Volume II. Washington, D.C.: U.S. Government Printing Office, 1984-5.]**PEER REVIEWED**

Chromosome damage in vitro in humans and rats has been reported, and Ehrlich ascites liver cells show chromosome lesions after incubation with methyl hydrazine.
[American Conference of Governmental Industrial Hygienists, Inc. Documentation of the Threshold Limit Values and Biological Exposure Indices. 6th ed. Volumes I,II, III. Cincinnati, OH: ACGIH, 1991. 1010]**PEER REVIEWED**

Skin, Eye and Respiratory Irritations:

Vapor is irritating to eyes, nose & throat.
[U.S. Coast Guard, Department of Transportation. CHRIS - Hazardous Chemical Data. Volume II. Washington, D.C.: U.S. Government Printing Office, 1984-5.]**PEER REVIEWED**

Skin irritation is pronounced with the propellant hydrazines ... /Hydrazine & derivatives/
[International Labour Office. Encyclopedia of Occupational Health and Safety. Vols. I&II. Geneva, Switzerland: International Labour Office, 1983. 1069]**PEER REVIEWED**

All hydrazines have similar toxic local effects due to their irritant properties. The vapor is highly irritating to the eyes, upper respiratory tract, & skin ... /Hydrazines/
[Sittig, M. Handbook of Toxic and Hazardous Chemicals and Carcinogens, 1985. 2nd ed. Park Ridge, NJ: Noyes Data Corporation, 1985. 502]**PEER REVIEWED**

Medical Surveillance:

Placement medical examinations shall include at least: comprehensive medical and work histories; comprehensive physical examination; specific clinical tests including complete and differential blood count; liver function tests including serum glutamic-pyruvic transaminase (SGPT), urinalysis including specific gravity, glucose, protein, and microscopic examination, and a 14 x 17 inch posteroanterior chest roentenogram; a judgement of the worker's ability to use positive pressure respirators; and urobilinogen and serum bilirubin tests shall be considered by the responsible physician. Periodic examinations shall be made available at least annually to those working with hydrazines. /Hydrazines/
[NIOSH; Criteria Document: Hydrazine p.3 (1978) DHEW Pub. NIOSH 78-172]**PEER REVIEWED**

Probable Routes of Human Exposure:

Monomethylhydrazine ... is a decomposition product of the mushroom toxin, gyromitrin (Gyromitra esculenta) ... /when/ generated in vivo is believed to be responsible for the toxicity of gyromitrin.
[Gosselin, R.E., R.P. Smith, H.C. Hodge. Clinical Toxicology of Commercial Products. 5th ed. Baltimore: Williams and Wilkins, 1984.,p. II-247]**PEER REVIEWED**

Human exposure to methylhydrazine most likely results from its use as a component of aerospace propellants. NIOSH (NOES Survey 1981-1983) has estimated that 1,473 workers (230 of these are female) are exposed to methylhydrazine in the USA(1). The general population may be exposed to methylhydrazine via dermal contact with vapors and other products containing methylhydrazine(SRC).
[(1) NIOSH: National Occupational Exposure Survey (NOES) (1983)]**PEER REVIEWED**

Emergency Medical Treatment:

Emergency Medical Treatment:

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The following Overview, *** METHYL HYDRAZINE ***, is relevant for this HSDB record chemical.

Life Support:
  o   This overview assumes that basic life support measures
      have been instituted.                           
Clinical Effects:
  SUMMARY OF EXPOSURE
   0.2.1.1 ACUTE EXPOSURE
     o   Methyl hydrazine is more toxic than hydrazine.  It can
         be absorbed by any route.  It is corrosive to the skin
         and eyes.  It is a CNS stimulant and can induce blood
         dyscrasias.  It is an animal carcinogen and a suspected
         human carcinogen.  Liver and kidney damage have been
         reported in animals.
  VITAL SIGNS
   0.2.3.1 ACUTE EXPOSURE
     o   Anoxia, cyanosis, or fever may occur.  Respiratory
         arrest may occur secondary to seizure activity or coma.
  HEENT
   0.2.4.1 ACUTE EXPOSURE
     o   Methyl hydrazine is irritating to the eyes, nose, and
         throat.  Vapors may cause eye irritation.  Liquids may
         cause severe eye damage.  Facial edema, conjunctivitis,
         and salivation have been reported from exposure to
         hydrazines.
  RESPIRATORY
   0.2.6.1 ACUTE EXPOSURE
     o   Acute exposure to low concentrations of hydrazines may
         cause delayed death (days) and produce bronchial mucous
         membrane damage and pulmonary edema.
  NEUROLOGIC
   0.2.7.1 ACUTE EXPOSURE
     o   CNS stimulation, excitability, tremors, convulsions,
         and coma have occurred.
  GASTROINTESTINAL
   0.2.8.1 ACUTE EXPOSURE
     o   Nausea, vomiting, diarrhea and anorexia are common
         symptoms.  The nausea may be refractory to medication.
  HEPATIC
   0.2.9.1 ACUTE EXPOSURE
     o   Fatty degeneration and occasional hepatic necrosis may
         occur in human poisonings.  Elevations in alkaline
         phosphatase and bilirubin, hepatic cholestasis, and
         hepatic hemosiderosis occurred in dogs.
  GENITOURINARY
   0.2.10.1 ACUTE EXPOSURE
     o   Severe renal damage, possibly secondary to hemolysis,
         may occur.
  HEMATOLOGIC
   0.2.13.1 ACUTE EXPOSURE
     o   Methemoglobinemia, Heinz bodies, and hemolytic anemia
         have occurred in animals.  Induction of Heinz bodies in
         humans is suggestive of similar effects.  Methyl
         hydrazine is the most potent hemolyzer of the
         hydrazines.
  DERMATOLOGIC
   0.2.14.1 ACUTE EXPOSURE
     o   Methyl hydrazine is corrosive to the skin.  Second- and
         third-degree burns can occur upon brief exposure.  Some
         hydrazines are skin sensitizers.
  MUSCULOSKELETAL
   0.2.15.1 ACUTE EXPOSURE
     o   Hydrazine has produced arthralgias.
  ENDOCRINE
   0.2.16.1 ACUTE EXPOSURE
     o   Hypoglycemia or hyperglycemia may occur, depending on
         the glycogen reserves in the liver.
  IMMUNOLOGIC
   0.2.19.2 CHRONIC EXPOSURE
     o   Some hydrazines are skin sensitizers.
  REPRODUCTIVE HAZARDS
    o   Contradictory results have been obtained for induction
        of malformations in mice.  Sperm head abnormalities were
        reversibly induced in rats.  Methemoglobin inducers may
        be especially hazardous to the fetus.
  CARCINOGENICITY
   0.2.21.2 HUMAN OVERVIEW
     o   Methyl hydrazine is regarded as a Suspected Human
         Carcinogen by the ACGIH.
   0.2.21.3 ANIMAL OVERVIEW
     o   Inconsistent results have occurred in animal studies.
  GENOTOXICITY
    o   Methyl hydrazine appears to be weakly genotoxic at the
        level of DNA damage and mutations.  Chromosome
        aberrations have been reported in vitro.
  OTHER
   0.2.23.1 ACUTE EXPOSURE
     o   Methyl hydrazine can be hazardous by any route of
         exposure.
   0.2.23.2 CHRONIC EXPOSURE
     o   Accumulation in the body may occur.
Laboratory:
  o   If respiratory tract irritation or respiratory depression
      is evident, monitor arterial blood gases, chest x-ray, and
      pulmonary function tests.
  o   A number of chemicals produce abnormalities of the
      hematopoietic system, liver, and kidneys.  Monitoring
      complete blood count, urinalysis, and liver and kidney
      function tests is suggested for patients with significant
      exposure.
  o   Monitor methemoglobin and blood sugar.
Treatment Overview:
  ORAL EXPOSURE
    o   Do NOT induce emesis.
    o   DILUTION:  Immediately dilute with 4 to 8 ounces (120 to
        240 mL) of milk or water (not to exceed 4 ounces/120 mL
        in a child).
    o   Significant esophageal or gastrointestinal tract
        irritation or burns may occur following ingestion.  The
        possible benefit of early removal of some ingested
        material by cautious gastric lavage must be weighed
        against potential complications of bleeding or
        perforation.
     1.  GASTRIC LAVAGE:  Consider after ingestion of a
         potentially life-threatening amount of poison if it can
         be performed soon after ingestion (generally within 1
         hour).  Protect airway by placement in Trendelenburg
         and left lateral decubitus position or by endotracheal
         intubation.  Control any seizures first.
      a.  CONTRAINDICATIONS:  Loss of airway protective reflexes
          or decreased level of consciousness in unintubated
          patients; following ingestion of corrosives;
          hydrocarbons (high aspiration potential); patients at
          risk of hemorrhage or gastrointestinal perforation;
          and trivial or non-toxic ingestion.
    o   ACTIVATED CHARCOAL:  Administer charcoal as a slurry
        (240 mL water/30 g charcoal).  Usual dose:  25 to 100 g
        in adults/adolescents, 25 to 50 g in children (1 to 12
        years), and 1 g/kg in infants less than 1 year old.
    o   SEIZURES:  Administer a benzodiazepine IV; DIAZEPAM
        (ADULT:  5 to 10 mg,  repeat every 10 to 15 min as
        needed.  CHILD:  0.2 to 0.5 mg/kg, repeat every  5 min
        as needed) or LORAZEPAM (ADULT:  2 to 4 mg; CHILD:  0.05
        to 0.1 mg/kg).
     1.  Consider phenobarbital if seizures recur after diazepam
         30 mg (adults)  or 10 mg (children > 5 years).
     2.  Monitor for hypotension, dysrhythmias, respiratory
         depression, and need  for endotracheal intubation.
         Evaluate for hypoglycemia, electrolyte disturbances,
         hypoxia.
    o   ACUTE LUNG INJURY:  Maintain ventilation and oxygenation
        and evaluate with frequent arterial blood gas or pulse
        oximetry monitoring.  Early use of PEEP and mechanical
        ventilation may be needed.
    o   METHEMOGLOBINEMIA:  Administer 1 to 2 mg/kg of 1%
        methylene blue slowly IV in symptomatic patients.
        Additional doses may be required.
    o   PYRIDOXINE (VITAMIN B6) - May be antidotal for
        neurologic symptoms.  There is limited experience in
        using pyridoxine as an antidote for methyl hydrazine.
        The dose recommended in the literature is 25 mg/kg given
        as an infusion over 15 to 30 minutes.  Repeat doses may
        be administered for recurring neurologic signs (coma,
        seizures) to a maximum total daily dose of 15 to 20
        grams.  See Precautions in Section 6.5.2.
  INHALATION EXPOSURE
    o   Rescuers must not enter areas with potential high
        airborne concentrations of this agent without
        SELF-CONTAINED BREATHING APPARATUS (SCBA) to avoid
        becoming secondary victims.
    o   INHALATION:  Move patient to fresh air.  Monitor for
        respiratory distress.  If cough or difficulty breathing
        develops, evaluate for respiratory tract irritation,
        bronchitis, or pneumonitis.  Administer oxygen and
        assist ventilation as required.  Treat bronchospasm with
        beta2  agonist and corticosteroid aerosols.
    o   SEIZURES:  Administer a benzodiazepine IV; DIAZEPAM
        (ADULT:  5 to 10 mg,  repeat every 10 to 15 min as
        needed.  CHILD:  0.2 to 0.5 mg/kg, repeat every  5 min
        as needed) or LORAZEPAM (ADULT:  2 to 4 mg; CHILD:  0.05
        to 0.1 mg/kg).
     1.  Consider phenobarbital if seizures recur after diazepam
         30 mg (adults)  or 10 mg (children > 5 years).
     2.  Monitor for hypotension, dysrhythmias, respiratory
         depression, and need  for endotracheal intubation.
         Evaluate for hypoglycemia, electrolyte disturbances,
         hypoxia.
    o   ACUTE LUNG INJURY:  Maintain ventilation and oxygenation
        and evaluate with frequent arterial blood gas or pulse
        oximetry monitoring.  Early use of PEEP and mechanical
        ventilation may be needed.
    o   METHEMOGLOBINEMIA:  Administer 1 to 2 mg/kg of 1%
        methylene blue slowly IV in symptomatic patients.
        Additional doses may be required.
    o   PYRIDOXINE (VITAMIN B6) - May be antidotal for
        neurologic symptoms.  There is limited experience in
        using pyridoxine as an antidote for methyl hydrazine.
        The dose recommended in the literature is 25 mg/kg given
        as an infusion over 15 to 30 minutes.  Repeat doses may
        be administered for recurring neurologic signs (coma,
        seizures) to a maximum total daily dose of 15 to 20
        grams.
  EYE EXPOSURE
    o   DECONTAMINATION:  Irrigate exposed eyes with copious
        amounts of tepid water for at least 15 minutes.  If
        irritation, pain, swelling, lacrimation, or photophobia
        persist, the patient should be seen in a health care
        facility.
    o   Treatment should include recommendations listed in the
        ORAL EXPOSURE section when appropriate.
  DERMAL EXPOSURE
    o   Methyl hydrazine can SPONTANEOUSLY IGNITE upon contact
        with cloth; clothing should be removed immediately.
    o   DECONTAMINATION:  Remove contaminated clothing and wash
        exposed  area thoroughly with soap and water.  A
        physician may need to  examine the area if irritation or
        pain persists.
    o   Treat dermal irritation or burns with standard topical
        therapy.  Patients developing dermal hypersensitivity
        reactions may require treatment with systemic or topical
        corticosteroids or antihistamines.
    o   SEIZURES:  Administer a benzodiazepine IV; DIAZEPAM
        (ADULT:  5 to 10 mg,  repeat every 10 to 15 min as
        needed.  CHILD:  0.2 to 0.5 mg/kg, repeat every  5 min
        as needed) or LORAZEPAM (ADULT:  2 to 4 mg; CHILD:  0.05
        to 0.1 mg/kg).
     1.  Consider phenobarbital if seizures recur after diazepam
         30 mg (adults)  or 10 mg (children > 5 years).
     2.  Monitor for hypotension, dysrhythmias, respiratory
         depression, and need  for endotracheal intubation.
         Evaluate for hypoglycemia, electrolyte disturbances,
         hypoxia.
    o   ACUTE LUNG INJURY:  Maintain ventilation and oxygenation
        and evaluate with frequent arterial blood gas or pulse
        oximetry monitoring.  Early use of PEEP and mechanical
        ventilation may be needed.
    o   METHEMOGLOBINEMIA:  Administer 1 to 2 mg/kg of 1%
        methylene blue slowly IV in symptomatic patients.
        Additional doses may be required.
    o   PYRIDOXINE (VITAMIN B6) - May be antidotal for
        neurologic symptoms.  There is limited experience in
        using pyridoxine as an antidote for methyl hydrazine.
        The dose recommended in the literature is 25 mg/kg given
        as an infusion over 15 to 30 minutes.  Repeat doses may
        be administered for recurring neurologic signs(coma,
        seizures) to a maximum total daily dose of 15 to 20 g.
Range of Toxicity:
  o   Minimum lethal human exposure is unknown.    

[Rumack BH: POISINDEX(R) Information System. Micromedex, Inc., Englewood, CO, 2003; CCIS Volume 115, edition exp February, 2003. Hall AH & Rumack BH (Eds):TOMES(R) Information System. Micromedex, Inc., Englewood, CO, 2003; CCIS Volume 115, edition exp February, 2003.] **PEER REVIEWED**

Antidote and Emergency Treatment:

Specific treatment for exposure consists of thorough washing of all exposed skin areas with soap and water, copious irrigation of the eyes, and prompt removal of the patient from the source of exposure. /Hydrazines/
[Haddad, L.M., Clinical Management of Poisoning and Drug Overdose. 2nd ed. Philadelphia, PA: W.B. Saunders Co., 1990. 1287]**PEER REVIEWED**

After inhalation, observation for progressive respiratory distress is necessary. Chest X-ray and arterial blood gases should be monitored. Administration of oxygen, intubation, and assisted ventilation may become necessary. Pneumonia and bronchitis need to be excluded. /Hydrazines/
[Haddad, L.M., Clinical Management of Poisoning and Drug Overdose. 2nd ed. Philadelphia, PA: W.B. Saunders Co., 1990. 1287]**PEER REVIEWED**

If ingestion has occurred, gastric lavage or emesis should be followed by administration of activated charcoal and catharsis. Emesis is most effective if it is initiated within 30 minutes of ingestion. /Hydrazines/
[Haddad, L.M., Clinical Management of Poisoning and Drug Overdose. 2nd ed. Philadelphia, PA: W.B. Saunders Co., 1990. 1287]**PEER REVIEWED**

Pyridoxine may be antidotal. The suggested dose is with half of this dose given intramuscularly and two-thirds given IV over 3 hours. Seizures should be controlled with diazepam, phenytoin, or phenobarbital. Blood sugar levels should be monitored for severe hypoglycemia, which may appear with or without preceding significant hyperglycemia. The patient should be observed for evidence of intravascular hemolysis, methemoglobinemia, and consequent deterioration of renal function. Patients who are symptomatic or who demonstrate a methemoglobin level greater than 30 per cent should be treated with methylene blue slowly IV every 4 hours as needed. Improvement is dramatic if diagnosis is correct. Liver function should be monitored because hydrazines are known hepatotoxins. /Hydrazines/
[Haddad, L.M., Clinical Management of Poisoning and Drug Overdose. 2nd ed. Philadelphia, PA: W.B. Saunders Co., 1990. 1287]**PEER REVIEWED**

Elimination is enhanced by forced diuresis and acidification of the urine. Hemodialysis and peritoneal dialysis should be effective, but insufficient human data exist on the use of these modalities. Treatment is otherwise symptomatic and supportive. /Hydrazines/
[Haddad, L.M., Clinical Management of Poisoning and Drug Overdose. 2nd ed. Philadelphia, PA: W.B. Saunders Co., 1990. 1287]**PEER REVIEWED**

Animal Toxicity Studies:

Evidence for Carcinogenicity:

A3; Confirmed animal carcinogen with unknown relevance to humans.
[American Conference of Governmental Industrial Hygienists. TLVs & BEIs: Threshold limit Values for Chemical Substances and Physical Agents andBiological Exposure Indices for 2002. Cincinnati, OH. 2002. 42]**QC REVIEWED**

Non-Human Toxicity Excerpts:

WHEN /MONOMETHYLHYDRAZINE/ ... APPLIED TO SKIN OF DOGS, IT IS ABSORBED & CARRIED BY BLOODSTREAM TO EYES WHERE IT ENTERS AQ HUMOR & INJURES ENDOTHELIUM OF CORNEA, CAUSING CORNEAL EDEMA IN 5-6 HR. IN EXCISED CORNEAS SOLN AS DIL AS 1X10-7 MOLAR ... /PROMOTED/ SWELLING OF CORNEA ...
[Grant, W.M. Toxicology of the Eye. 3rd ed. Springfield, IL: Charles C. Thomas Publisher, 1986. 619]**PEER REVIEWED**

METHYLHYDRAZINE WAS MUTAGENIC AFTER ACTIVATION IN MICROBIAL REVERSION TESTS, CONDUCTED AS SUSPENSION TESTS WITH SALMONELLA TYPHIMURIUM TA-1535.
[BRUSICK D, MATHESON D; AEROSP MED RES LAB (TECH REP) AMRL-TR (US); ISS AMRL-TR-76-125 (PROC ANNU CONF ENVIRON TOXICOL) 7TH; AD/A-041 973, 108-29 (1977)]**PEER REVIEWED**

DOGS WERE EXPOSED AT 1, 2, 5 & 10 PPM. A 2 PPM EXPOSURE FOR 6 MO PRODUCED 5.7% ERYTHROCYTE HEMOLYSIS THROUGH METHEMOGLOBIN HEINZ BODY TRANSFORMATION MECHANISM. THIS EFFECT WAS FOLLOWED BY RETICULOCYTOSIS. CONTINUOUS 90 DAY EXPOSURE PRODUCED MEASURABLE EFFECTS IN DOGS & RATS. BEAGLE DOGS SHOWED SIGNIFICANT INCR IN SERUM PHOSPHORUS & ALKALINE PHOSPHATASE LEVELS DURING THE EXPOSURE PERIOD.
[DARMER KI JR, MACEWEN JD; 4TH PROC ANNU CONF ENVIRON TOXICOL 373-85 (1973)]**PEER REVIEWED**

TERATOGENIC EFFECTS OF METHYLHYDRAZINE IN CONCN IN EXCESS OF 10 MG/L ON EMBRYOS OF THE SOUTH AFRICAN CLAWED TOAD WAS STUDIED. MALFORMATIONS OF THE HEAD, TRUNK, & TAIL OF OCCURRED. THE MOST COMMON ABNORMALITY OBSERVED WAS TAIL KINKS. OTHER ABNORMALITIES OBSERVED WERE MICROCEPHALY, CYCLOPIA, SHORTENING OF TRUNK, & EDEMA.
[GREENHOUSE G; TERATOLOGY 13 (2): 167-77 (1976)]**PEER REVIEWED**

A 0.01% SOLN OF METHYLHYDRAZINE WAS ADMIN DAILY IN DRINKING WATER TO 6 WK OLD SYRIAN GOLDEN HAMSTERS FOR LIFE. TREATMENT GAVE RISE TO MALIGNANT HISTIOCYTOMAS OF LIVER & TUMORS OF CECUM.
[TOTH B, SHIMIZU H; CANCER RES 33 (11): 2744-53 (1973)]**PEER REVIEWED**

MONOMETHYLHYDRAZINE INDUCED ABNORMALITIES IN MORPHOLOGY OF SPERM IN THE CAUDA EPIDIDYMIDES OF MICE WHICH REACHED MAX LEVELS 3 WEEKS AFTER CHEM TREATMENT.
[WYROBEK AJ, LONDON SA; 4TH PROC ANNU CONF ENVIRON TOXICOL 417-32 (1973)]**PEER REVIEWED**

IT IS NOT REPORTED TO BE SKIN SENSITIZER BUT IT CAUSES MANY HEMATOLOGIC ABNORMALITIES IN VARIETY OF TEST SPECIES. THESE INCL HEMOLYTIC ANEMIA (WITH REDN IN ERYTHROCYTES, HEMOGLOBIN, HEMATOCRIT VALUES) INCR IN METHEMOGLOBIN, AN INCR IN HEINZ BODIES & LIVER, KIDNEY, & SPLEEN HEMOSIDEROSIS, AS WELL AS LIVER CHOLESTASIS ...
[Clayton, G. D. and F. E. Clayton (eds.). Patty's Industrial Hygiene and Toxicology: Volume 2A, 2B, 2C: Toxicology. 3rd ed. New York: John Wiley Sons, 1981-1982. 2801]**PEER REVIEWED**

METHYLHYDRAZINE GAVE NEGATIVE RESULTS IN AMES TESTS WITH SALMONELLA TYPHIMURIUM TA100 AS INDICATOR STRAIN. IN HOST MEDIATED ASSAY, METHYLHYDRAZINE SHOWED MARGINAL MUTAGENIC ACTIVITY. SALMONELLA TYPHIMURIUM TA1950 WAS THE INDICATOR STRAIN.
[VON WRIGHT A, TIKKANEN L; MUTAT RES 78 (1): 17-23 (1980)]**PEER REVIEWED**

AN IMPORTANT FEATURE OF THE ACUTE SEIZURE MODEL INVOLVING EXPOSURE TO THE CONVULSANT, MONOMETHYLHYDRAZINE (MMH), IS THE LATENCY IN MINUTES POSTINJECTION TO THE ONSET OF GENERALIZED TONIC CLONIC CONVULSIONS. POSTOPERATIVE MONOMETHYLHYDRAZINE LATENCIES IN 8 NAIVE CATS WERE COMPARED WITH SUBSEQUENT AFTER DISCHARGE THRESHOLDS OBTAINED FROM BASOLATERAL AMYGDALA KINDLING ELECTRODES. THE CORRELATION BETWEEN THOSE 2 INDICES WAS STATISTICALLY SIGNIFICANT. CATS DIVIDED ON BASIS OF MEDIAN POPULATION VALUE INTO HIGH OR LOW MONOMETHYLHYDRAZINE SEIZURE LATENCIES DIFFERED SIGNIFICANTLY FROM ONE ANOTHER ON THAT INDEX. ANIMALS WITH PROLONGED SEIZURE LATENCIES SHOWED SIGNIFICANTLY HIGHER AFTERDISCHARGE THRESHOLDS, WHEREAS SHORTER LATENCIES ACCOMPANIED LOWER AFTER DISCHARGE THRESHOLDS. THE GENDER, WT, ELECTRODE IMPEDANCE OR ELECTRODE SITES OF INDIVIDUALS DID NOT ACCOUNT FOR THIS RELATIONSHIP. RESULTS SUGGEST ENDOGENOUS DIFFERENCES IN SEIZURE SUSCEPTIBILITY THAT ARE DEFINABLE REGARDLESS OF PROCEDURE.
[SHOUSE MN, STEVMAN MB; EXP NEUROL 66 (3): 667-73 (1979)]**PEER REVIEWED**

METHYLHYDRAZINE INDUCED MUTATIONS IN SEVERAL STRAINS OF ESCHERICHIA COLI INDEPENDENTLY OF THE REC A & LEX A LOCI, INDICATING THAT THE MUTAGENIC EFFECT WAS NOT DEPENDENT ON ERROR PRONE REPAIR ACTIVITY.
[VON WRIGHT A, TIKKANEN L; MUTAT RES 71 (2): 269-71 (1980)]**PEER REVIEWED**

THE TOXICITY OF MONOMETHYLHYDRAZINE, HYDRAZINE & UNSYMMETRICAL DIMETHYLHYDRAZINE WAS DETERMINED FOR MIXED & UNICULTURE CULTURES OF NITRIFYING, DENITRIFYING, & ANAEROBIC METHANOGENIC BACTERIA. MONOMETHYLHYDRAZINE WAS MORE TOXIC THAN HYDRAZINE, WHICH WAS MORE TOXIC THAN DIMETHYLHYDRAZINE.
[KANE DA, WILLIAMSON KJ; ARCH ENVIRON CONTAM TOXICOL 12 (4): 447-53 (1983)]**PEER REVIEWED**

SELECTED HYDRAZINES WERE EXAMINED FOR THEIR MUTAGENIC ACTIVITY IN SALMONELLA TYPHIMURIUM STRAINS TA15357 TA1537. THESE IN VITRO ASSAYS WERE CONDUCTED WITH & WITHOUT METABOLIC ACTIVATION BY AROCLOR INDUCED RAT LIVER ENZYMES. HIGH LEVEL OF MUTAGENICITY WAS OBSERVED WITH METHYLHYDRAZINE & PHENYLHYDRAZINE HYDROCHLORIDE.
[ROGAN EG ET AL; MUTAT RES 102 (4): 413-24 (1982)]**PEER REVIEWED**

GROUPS OF DOGS, MONKEYS, & RATS WERE EXPOSED CONTINUOUSLY TO MONOMETHYLHYDRAZINE FOR 90 DAYS IN THOMAS DOME CHAMBERS TO ESTABLISH SPECIFIC EXPOSURE SAFETY STD. ANIMALS WERE ALSO EXPOSED TO DURATIONS UP TO 24 HR IN CONFINED WORKING AREAS. RESULTS INDICATE THAT ATMOSPHERIC CONCN OF 0.04 PPM MONOMETHYLHYDRAZINE IS SAFE FOR CONTINUOUS EXPOSURE IN CONFINED WORKING AREAS. A LEVEL OF 1 PPM MONOMETHYLHYDRAZINE IS SAFE CONCN FOR 24 HR EMERGENCY EXPOSURE LIMIT.
[DARMER KI JR, MACEWEN JD; 4TH PROC ANNU CONF ENVIRON TOXICOL; 373-85 (1973)]**PEER REVIEWED**

With oral doses of 20 mg/kg when admin on days 8 through 12 of mouse pregnancy ... 36% of offspring /were/ malformed. A dose of 200 mg/kg in rabbit on 14th day produced an equal number of /abnormal/ offspring. The anomalies consisted of anencephaly, eye defects & complex facial bone deformities.
[Shepard, T.H. Catalog of Teratogenic Agents. 5th ed. Baltimore, MD: The Johns Hopkins University Press, 1986. 381]**PEER REVIEWED**

Methylhydrazine was tested for mutagenicity in the Salmonella/microsome preincubation assay using the standard protocol approved by the National Toxicology Program. Methylhydrazine was tested at doses of 1.0, 3.3, 10, 33, and 100 ug/plate in as many as 5 Salmonella typhimurium strains (TA1535, TA1537, TA97, TA98, and TA100) in the presence and absence of rat or hamster liver S-9. Methylhydrazine was negative in these tests and the highest ineffective dose tested in any S typhimurium strain was 100 ug/plate.
[Mortelmans K et al; Environ Mutagen 8: 1-119 (1986)]**PEER REVIEWED**

SC INFUSION OF 30 UMOL/KG/HR OF METHYLHYDRAZINE FOR 14 HR INTERFERED WITH GLYCOLYSIS IN RATS BY INHIBITING PHOSPHOFRUCTOKINASE. CHRONIC EXPOSURE TO MORE THAN 0.6 UMOL/KG/HR OBSTRUCTED METHYLAMINE OXIDN. PUTRESCINE OXIDN WAS LESS SENSITIVE.
[DOST FM; AEROSP MED RES LAB (TECH REP) AMRL-TR (US); (AMRL-TR-125): 257-73 (1975)]**PEER REVIEWED**

The embryotoxicity and teratogenicity of monomethylhydrazine, unsymmetrical dimethylhydrazine and symmetrical dimethylhydrazine were investigated in Fischer 344 rats. On days 6 to 15 of gestation, rats were given ip injections of 2.5, 5.0, or 20 mg/kg monomethylhydrazine; 10, 30, or 60 mg/kg unsymmetrical dimethylhydrazine; or 2.0, 5.0, or 10.0 mg/kg symmetrical hydrazine. Animals were sacrificed on day 20 of gestation, and uteri were opened. Numbers and positions of implants, dead and live fetuses, and resorptions were recorded. Live fetuses were examined for abnormalities. Visceral and skeletal examinations were performed. Maternal weight gain was significantly depressed in rats given monnomethylhydrazine and unsymmetrical dimethylhydrazine; symmetrical dimethylhydrazine had an inconsistent effect on maternal weight gain. Treatment with monomethylhydrazine had an inconsistent effect on litter parameters. At doses of 5.0 or 10 mg/kg monomethylhydrazine there was an insignificant increase in litters exhibiting 33% or more resorptions and in incidence of abnormalities. Treatment with 60 mg/kg unsymmetrical dimethylhydrazine produced a significant reduction in mean fetal weight; numbers of implants and viable fetuses were less than in untreated controls. Nearly 50% of rats treated with 60 mg/kg unsymmetrical dimethylhydrazine had a resorption incidence of greater than 33%, and malformations were increased. Treatment with 10 mg/kg symmetrical dimethylhydrazine caused a moderate decrease in mean viable fetuses per litter, and mean fetal weight was significantly reduced. A slight reduction was seen in incidence of malformations and litters with 33% or more resorption. No teratogenic effects were seen in any of the derivatives. The /results/ conclude that unsymmetrical dimethylhydrazine and symmetrical dimethylhydrazine are embryotoxic in rats.
[Keller WC et al; J Toxicol Environ Health 13 (1): 125-31 (1984)]**PEER REVIEWED**

Acute toxicity is characterized by convulsions, neurological hyperexcitability, hypoglycemia, vomiting, anemia, bilirubinemia, methemoglobinemia, and ocular and upper respiratory tract irritation. Pathological changes in the lungs, liver, kidneys, and brain were observed in animals receiving acutely toxic doses.
[American Conference of Governmental Industrial Hygienists, Inc. Documentation of the Threshold Limit Values and Biological Exposure Indices. 6th ed. Volumes I,II, III. Cincinnati, OH: ACGIH, 1991. 1009]**PEER REVIEWED**

Treated skin sites exhibited erythema, edema, and a blanched appearance /in acute dermal studies/.
[American Conference of Governmental Industrial Hygienists, Inc. Documentation of the Threshold Limit Values and Biological Exposure Indices. 6th ed. Volumes I,II, III. Cincinnati, OH: ACGIH, 1991. 1009]**PEER REVIEWED**

Methyl hydrazine applied to the skin of dogs was carried by the bloodstream to the eyes where it entered the aq humor and caused corneal edema. Dilute soln as low as 10-7 M applied directly to corneal explants caused corneal swelling.
[American Conference of Governmental Industrial Hygienists, Inc. Documentation of the Threshold Limit Values and Biological Exposure Indices. 6th ed. Volumes I,II, III. Cincinnati, OH: ACGIH, 1991. 1009]**PEER REVIEWED**

A 6-mo inhalation study was performed in which rats, mice, dogs, and monkeys were exposed at 0, 0.2, 1, 2, or 5 ppm methyl hydrazine for 6 hours/day, 5 days/wk. ... Body weight reductions occurred in rats exposed at 1 to 5 ppm; compound-related effects at 0.2 ppm were not observed. Hemolytic anemia and the presence of Heinz bodies were observed in dogs inhaling 0.2 ppm and higher. Dogs exposed at 2 ppm and 5 ppm had incr methemoglobin formation, but both the anemia and methemoglobin were reversible. Alkaline phosphatase and bilirubin were also elevated in dogs in a dose-related manner at all exposure concn and were considered indicative of liver damage. Suppression of the flow of bile (hepatic cholestasis) was observed in dogs exposed at 0.2 ppm and higher, and hepatic and renal tubular hemosiderosis were observed at 2 ppm and 5 ppm. Incr mortality at 2 ppm and 5 ppm was noted in mice. Concn-related incr in hepatic, splenic, and renal tubular hemosiderosis were observed in mice. AT 2 ppm or 5 ppm, mice had periportal or centrilobular cholestasis and bile duct proliferation. Hemolysis and Heinz bodies formation in erythrocytes were observed in monkeys inhaling 5 ppm; however, compound-related effects at lower doses were not observed.
[American Conference of Governmental Industrial Hygienists, Inc. Documentation of the Threshold Limit Values and Biological Exposure Indices. 6th ed. Volumes I,II, III. Cincinnati, OH: ACGIH, 1991. 1009]**PEER REVIEWED**

... When rats, dogs, and monkeys inhaled methyl hydrazine 24 hours/day, 7 days/wk for 90 days at vapor concn of 0, 0.04, or 0.1 ppm methyl hydrazine, hematological effects in rats and dogs were seen at 0.1 ppm, discoloration of the liver occurred at 0.1 ppm in dogs, and serum phosphorus was elevated in rats at 0.04 and 0.1 ppm. No compound-related effects were reported in monkeys.
[American Conference of Governmental Industrial Hygienists, Inc. Documentation of the Threshold Limit Values and Biological Exposure Indices. 6th ed. Volumes I,II, III. Cincinnati, OH: ACGIH, 1991. 1009]**PEER REVIEWED**

... Methyl hydrazine was found to produce pulmonary tumors in mice and malignant histiocytoma of the liver and cecal tumors in hamsters when admin in the drinking water at concn of 0.01%.
[American Conference of Governmental Industrial Hygienists, Inc. Documentation of the Threshold Limit Values and Biological Exposure Indices. 6th ed. Volumes I,II, III. Cincinnati, OH: ACGIH, 1991. 1010]**PEER REVIEWED**

Exposures to methyl hydrazine at concn of 0 ppm and 0.02 ppm (rats and mice only) and 0.2, 2, or 5 ppm (rats and hamsters only) were conducted for 6 hours/day, 5 days/wk, over a period of 1 yr and were followed by observation for 1 yr. Rats that inhaled 0.02 ppm and above experienced a decr rats of growth which persisted through the postexposure observation period. A cmpd-related incr in tumors was not detected in rats at any dose. Mice exposed at 0.02 ppm and above exhibited nasal irritation and plasmacytosis. Renal cysts and hydronephrosis were observed in mice that inhaled 0.2 ppm and 2 ppm, respectively, and mice exposed at 2 ppm had a significantly higher incidence of lung tumors, nasal adenomas, nasal polyps, nasal osteomas, hemangiomas, and liver adenomas and carcinomas compared with control mice.
[American Conference of Governmental Industrial Hygienists, Inc. Documentation of the Threshold Limit Values and Biological Exposure Indices. 6th ed. Volumes I,II, III. Cincinnati, OH: ACGIH, 1991. 1010]**PEER REVIEWED**

Rhinitis and an incr number of biliary cysts were observed in hamsters exposed at 0.2 ppm or greater of methyl hydrazine. The numbers of nasal polyps, interstitial fibrosis of the kidney, and benign adrenal adenoma were incr in hamsters that inhaled 2 ppm or 5 ppm. Hamsters exposed at 5 ppm exhibited reduced body weights and an incr incidence of nasal adenomas. Dogs exposed to methyl hydrazine failed to develop pathological changes; however, exposure at 0.2 ppm and above caused transient anemia, reduced hematocrit, and reduced hemoglobin. Exposure of dogs at 2 ppm also results in a reversible incr in methemoglobin, alkaline phosphatase, bilirubin, and serum glutamic-pyruvic transaminase (SGPT) ... .
[American Conference of Governmental Industrial Hygienists, Inc. Documentation of the Threshold Limit Values and Biological Exposure Indices. 6th ed. Volumes I,II, III. Cincinnati, OH: ACGIH, 1991. 1010]**PEER REVIEWED**

Methyl hydrazine was given to pregnant female rats by ip injection at doses of 2.5, 5.0, or 10 mg/kg on days 6 through 15 of gestation. Methyl hydrazine was assoc with a reduction in maternal body weights and some evidence for embryo-toxicity. There was an equivocal incr in ocular abnormalities.
[American Conference of Governmental Industrial Hygienists, Inc. Documentation of the Threshold Limit Values and Biological Exposure Indices. 6th ed. Volumes I,II, III. Cincinnati, OH: ACGIH, 1991. 1010]**PEER REVIEWED**

Mice receiving daily, repeated ip injections for 5 days of methyl hydrazine (at fractional doses of 0.25 or 0.4 mg/kg of the 3 mg/kg LD50) had a significantly greater percentage of mature sperm with abnormal head shapes observed 1 to 3 wk following treatment. Abnormalities were reversible within 7 wk following cessation of treatment.
[American Conference of Governmental Industrial Hygienists, Inc. Documentation of the Threshold Limit Values and Biological Exposure Indices. 6th ed. Volumes I,II, III. Cincinnati, OH: ACGIH, 1991. 1010]**PEER REVIEWED**

Methyl hydrazine is generally inactive in test designed to measure mutagenic activity ... However, a spot test in E. coli was weakly positive, and mutations have been described in that organism following methyl hydrazine treatment. ... Chromosome damage in vitro in humans and rats has been reported, and Ehrlich ascites liver cells show chromosome lesions after incubation with methyl hydrazine. Liver DNA damage in vivo using DNA alkaline elution techniques has been both positive and negative.
[American Conference of Governmental Industrial Hygienists, Inc. Documentation of the Threshold Limit Values and Biological Exposure Indices. 6th ed. Volumes I,II, III. Cincinnati, OH: ACGIH, 1991. 1010]**PEER REVIEWED**

Isolated hepatocytes and liver microsomes incubated with monomethylhydrazine, 1,1-dimethylhydrazine and 1,2-dimethylhydrazine produced free radical intermediates which were detected by ESR spectroscopy by using 4-pyridyl-1-oxide-t-butyl nitrone as spin trapping agent. The spectral features of the spin adducts derived from all three hydrazine derivatives corresponded to the values reported for the methyl free radical adduct of 4-pyridyl-1-oxide-t-butyl nitrone. In the microsomal preparatons, inhibitors of the mixed function oxidase system and the destruction of cytochrome p450 by pretreating the rats with cobalt chloride all decreased the free radical formation. Methimazole, an inhibitor of FAD-containing monoxygenase system, similarly decreased the activation of 1,1-dimethylhydrazine, but not that of monomethylhydrazine and 1,2-dimethylhydrazine. The addition to liver microsomes of physiological concentrations of glutathione (GSH) lowered by approx 80% the intensities of the ESR signals. Consistently, incubation of isolated hepatocytes with methylhydrazine decreased the intracellular GSH content, suggesting that GSH can effectively scavenge the methyl free radicals. The results obtained suggest that methyl free radicals could be the alkylating species responsible for the toxic and/or carcinogenic effect of methylhydrazines.
[Albano E et al; Free Radic Biol Med 6 (1): 3-8 (1989)]**PEER REVIEWED**

The ability of hydrazine, acetylphenylhydrazine, methylhydrazine, and phenylhydrazine to stimulate proteolysis in red cells has been characterized. All four hydrazines effectively stimulated proteolysis in red cells and in hemolysate as evidenced by a two to threefold increase in the rate of tyrosine release. The rate of tyrosine release varied linearly with time, increased with increasing concentration of hydrazine, and also increased as a function of hematocrit. The rank order for stimulation of proteolysis in red cells was phenylhydrazine greater than methylhydrazine greater than hydrazine approximately equal to acetylphenylhydrazine. Inhibitors of glycolysis in red cells only minimally (13-27%) decreased the rate of tyrosine release stimulated by the different hydrazines. Agents which diminished electron transport decreased the rate of tyrosine release. NADP inhibited the rate of tyrosine release stimulated by hydrazine, methylhydrazine, and acetylphenylhydrazine by approximately 36 to 41%; 2'-AMP was less effective. The rate of tyrosine release resulting from insult by the hydrazines was increased slightly by methylene blue, moderately inhibited (approximately 10 to 27%) by the chelator o-phenanthroline and inhibited approximately 30 to 40% by N-ethylmaleimide. Use of an oxygen-depleted atmosphere (nitrogen) increased slightly the rate of tyrosine release stimulated by hydrazines, in contrast, carbon monoxide decreased proteolysis stimulated by hydrazine, methylhydrazine, and acetylphenylhydrazine by approximately 50%. Although the antioxidants dimethylfuran, dimethylthiourea, and methylsulfoxide failed to diminish proteolysis stimulated by the hydrazines, N-acetylcysteine exerted a protective effect, decreasing hydrazine-stimulated tyrosine release in red cells approximately 30 to 50%. Inclusion of 3-amino-1,2,4-triazole in the incubation failed to increase further the rate of hydrazine-stimulated proteolysis. These data suggest that more reactive free radicals generated from the hydrazine are responsible for protein damage, that damaged protein (hemoglobin) is degraded via proteolysis, and that an ATP-independent process primarily participates in the degradation of abnormal proteins in the red cell. Thus, proteolytic enzymes present in the erythrocyte appear to exert a protective effect against cellular damage through the removal of abnormal proteins generated as a consequence of xenobiotic insult. The ability of proteolytic enzymes to recognize and degrade abnormal proteins may be of importance in using protein (hemoglobin)-xenobiotic adducts to assess exposure to toxic agents (risk assessment).
[Runge-Morris MA et al; Toxicol Appl Pharmacol 94 (3): 414-26 (1988)]**PEER REVIEWED**

Non-Human Toxicity Values:

LC50 Rat inhalation 74-78 ppm/4 hr (calculated)
[American Conference of Governmental Industrial Hygienists, Inc. Documentation of the Threshold Limit Values and Biological Exposure Indices. 6th ed. Volumes I,II, III. Cincinnati, OH: ACGIH, 1991. 1009]**PEER REVIEWED**

LC50 Mouse inhalation 56-65 ppm/4 hr (calculated)
[American Conference of Governmental Industrial Hygienists, Inc. Documentation of the Threshold Limit Values and Biological Exposure Indices. 6th ed. Volumes I,II, III. Cincinnati, OH: ACGIH, 1991. 1009]**PEER REVIEWED**

LC50 Hamster inhalation 143 ppm/4 hr (calculated)
[American Conference of Governmental Industrial Hygienists. Documentation of the Threshold Limit Values and Biological Exposure Indices. 5th ed. Cincinnati, OH:American Conference of Governmental Industrial Hygienists, 1986. 398]**PEER REVIEWED**

LD50 Mouse intravenous 33 mg/kg
[Kirk-Othmer Encyclopedia of Chemical Technology. 3rd ed., Volumes 1-26. New York, NY: John Wiley and Sons, 1978-1984.,p. V12 760 (1980)]**PEER REVIEWED**

LD50 Mouse oral 33 mg/kg
[Kirk-Othmer Encyclopedia of Chemical Technology. 3rd ed., Volumes 1-26. New York, NY: John Wiley and Sons, 1978-1984.,p. V12 760 (1980)]**PEER REVIEWED**

LD50 Rat intravenous 33 mg/kg
[Kirk-Othmer Encyclopedia of Chemical Technology. 3rd ed., Volumes 1-26. New York, NY: John Wiley and Sons, 1978-1984.,p. V12 760 (1980)]**PEER REVIEWED**

LD50 Rat oral 33 mg/kg
[Kirk-Othmer Encyclopedia of Chemical Technology. 3rd ed., Volumes 1-26. New York, NY: John Wiley and Sons, 1978-1984.,p. V12 760 (1980)]**PEER REVIEWED**

LD50 Guinea pig percutaneous 49 mg/kg
[Kirk-Othmer Encyclopedia of Chemical Technology. 3rd ed., Volumes 1-26. New York, NY: John Wiley and Sons, 1978-1984.,p. V12 760 (1980)]**PEER REVIEWED**

LD50 Rabbit intravenous 12 mg/kg
[Kirk-Othmer Encyclopedia of Chemical Technology. 3rd ed., Volumes 1-26. New York, NY: John Wiley and Sons, 1978-1984.,p. V12 760 (1980)]**PEER REVIEWED**

LD50 Dog intravenous 12 mg/kg
[Kirk-Othmer Encyclopedia of Chemical Technology. 3rd ed., Volumes 1-26. New York, NY: John Wiley and Sons, 1978-1984.,p. V12 760 (1980)]**PEER REVIEWED**

LC50 Monkey inhalation 162 ppm/1 hour
[American Conference of Governmental Industrial Hygienists, Inc. Documentation of the Threshold Limit Values and Biological Exposure Indices. 6th ed. Volumes I,II, III. Cincinnati, OH: ACGIH, 1991. 1009]**PEER REVIEWED**

LC50 Dog inhalation 96 ppm/1 hour
[American Conference of Governmental Industrial Hygienists, Inc. Documentation of the Threshold Limit Values and Biological Exposure Indices. 6th ed. Volumes I,II, III. Cincinnati, OH: ACGIH, 1991. 1009]**PEER REVIEWED**

LD50 Rabbit dermal 93 mg/kg
[American Conference of Governmental Industrial Hygienists, Inc. Documentation of the Threshold Limit Values and Biological Exposure Indices. 6th ed. Volumes I,II, III. Cincinnati, OH: ACGIH, 1991. 1009]**PEER REVIEWED**

LD50 Guinea pig dermal 47 mg/kg
[American Conference of Governmental Industrial Hygienists, Inc. Documentation of the Threshold Limit Values and Biological Exposure Indices. 6th ed. Volumes I,II, III. Cincinnati, OH: ACGIH, 1991. 1009]**PEER REVIEWED**

LD50 Hamster dermal 239 mg/kg
[American Conference of Governmental Industrial Hygienists, Inc. Documentation of the Threshold Limit Values and Biological Exposure Indices. 6th ed. Volumes I,II, III. Cincinnati, OH: ACGIH, 1991. 1009]**PEER REVIEWED**

LD50 Rat dermal 183 mg/kg
[American Conference of Governmental Industrial Hygienists, Inc. Documentation of the Threshold Limit Values and Biological Exposure Indices. 6th ed. Volumes I,II, III. Cincinnati, OH: ACGIH, 1991. 1009]**PEER REVIEWED**

Ecotoxicity Values:

LC50 Hyalella azteca (amphipod) 1.2 mg/l/48 hr. /Conditions of bioassay not specified/
[USEPA; Health and Environmental Effects Profile for Methylhydrazine p.23 (1987) ECAO-CIN-021]**PEER REVIEWED**

LC50 Guppies 2.6-6.7 mg/l/24 hr. /Conditions of bioassay not specified/
[USEPA; Health and Environmental Effects Profile for Methylhydrazine p.23 (1987) ECAO-CIN-021]**PEER REVIEWED**

Metabolism/Pharmacokinetics:

Metabolism/Metabolites:

N-OXIDATION OF METHYLHYDRAZINE CATALYZED BY PURIFIED MOUSE LIVER MICROSOMAL MIXED FUNCTION AMINE OXIDASE IS SHOWN. AT PH 7.7 & 25 DEG C, METHYLHYDRAZINE HAS NEARLY THE SAME MAXIMAL N-OXIDATION RATE AS DIMETHYLANILINE. ALTHOUGH METHANE CAN BE DETECTED AS A PRODUCT OF N-OXIDATION OF METHYLHYDRAZINE, IT MAY REPRESENT THE CHEMICAL DECOMP PRODUCT OF A N-OXIDIZED INTERMEDIATE.
[PROUGH RA; ARCH BIOCHEM BIOPHYS 158 (1): 442-4 (1973)]**PEER REVIEWED**

FLAVOPROTEIN N-OXYGENASE ... CATALYZES FORMATION OF ... N-OXIDES OF METHYLHYDRAZINE /&/ 1,1-DIMETHYLHYDRAZINE ...
[The Chemical Society. Foreign Compound Metabolism in Mammals Volume 3. London: The Chemical Society, 1975. 470]**PEER REVIEWED**

Absorption, Distribution & Excretion:

METHYLHYDRAZINE IS ABSORBED FROM THE LUNG, GI TRACT, INJECTION SITES, & SKIN.
[Clayton, G. D. and F. E. Clayton (eds.). Patty's Industrial Hygiene and Toxicology: Volume 2A, 2B, 2C: Toxicology. 3rd ed. New York: John Wiley Sons, 1981-1982. 2801]**PEER REVIEWED**

1.5 MG/MIN OF MONOMETHYLHYDRAZINE INFUSED IV INTO DOGS WAS EXCRETED BY COMBINATION OF GLOMERULAR FILTRATION, PASSIVE DIFFUSION MEDIATED REABSORPTION, & SIMULTANEOUS TUBULAR SECRETION.
[COE FL ET AL; J PHARMACOL EXP THER 163 (1): 216-21 (1968)]**PEER REVIEWED**

(14)C LABELED METHYLHYDRAZINE WAS ADMIN TO MICE, DOGS, & MONKEYS. ALL SPECIES EXCRETED 25-40% OF THE DOSE IN URINE WITHIN 24 HR. IN MICE ... APPROX THE SAME AMT WAS EXCRETED IN RESPIRED AIR. BOTH CARBON DIOXIDE AND RADIOACTIVE METHANE WERE FOUND.
[Clayton, G. D. and F. E. Clayton (eds.). Patty's Industrial Hygiene and Toxicology: Volume 2A, 2B, 2C: Toxicology. 3rd ed. New York: John Wiley Sons, 1981-1982. 2796]**PEER REVIEWED**

... WHEN MONOMETHYLHYDRAZINE ... APPLIED TO SKIN OF DOGS, IT IS ABSORBED & CARRIED BY BLOODSTREAM TO EYES WHERE IT ENTERS AQ HUMOR ...
[Grant, W.M. Toxicology of the Eye. 3rd ed. Springfield, IL: Charles C. Thomas Publisher, 1986. 619]**PEER REVIEWED**

The resp & urinary excretion of ip admin monomethylhydrazine (MMH) by rats was studied by means of radiotracer technique. Rats given 0.12 mM/kg respired approx 45% of the labeled carbon during the following 24 hr. Of the respired radioactivity, 20-25% was (14)C labeled carbon dioxide & the remainder was (14)C-methane. At the subconvulsive dose, 40% of the admin radioactivity was excreted in the urine. The percentage of urinary excretion from (14)C from higher doses was less, but the net amt excreted was slightly higher.
[Dost FN et al; Biochem Pharmacol 15 (9): 1325-32 (1966)]**PEER REVIEWED**

Undiluted methyl hydrazine applied to dog skin at doses of 14.7-264.5 mg/kg was detected in the blood within 30 sec following application.
[American Conference of Governmental Industrial Hygienists, Inc. Documentation of the Threshold Limit Values and Biological Exposure Indices. 6th ed. Volumes I,II, III. Cincinnati, OH: ACGIH, 1991. 1009]**PEER REVIEWED**

Mechanism of Action:

The enzyme systems in rat liver and lung responsible for the oxidative metabolism of hydrazine derivatives were studied to determine whether these enzymes, cytochrome p450 and monoamine oxidase, were responsible for metabolically activating hydrazines to carcinogenic/toxic metabolites. Cytochrome p450 preferentially oxidized the nitrogen to nitrogen bond of 1,2-disubstituted hydrazines and hydrazides, while monoamine oxidase oxidized the nitrogen to nitrogen bond of all the classes of hydrazine derivatives that were tested. Oxidation of the nitrogen to nitrogen bond led to the formation of stable azo intemediates in the case of 1,2-disubstituted hydrazines and to unstable monoazo (diazene) metabolites in the case of monosubstituted hydrazines and hydrazides. /Substituted hydrazines/
[Erikson JM, Prough RA; J Biochem Toxicol 1 (1): 41-52 (1986)]**PEER REVIEWED**

Interactions:

ADMIN OF METHYLHYDRAZINE TO MICE DECR SURVIVAL OF ANIMALS AFTER X-IRRADIATION, INHIBITED GROWTH OF EHRLICH ASCITES TUMOR, & INCR NUMBER OF CELLS WITH CHROMOSOME ABERRATIONS. DECR IN THE SH LEVEL WAS SUGGESTED AS RESPONSIBLE FOR RADIOSENSITIZING ACTIVITY.
[LE XUAN TU ET AL; RADIOBIOLOGIYA 15 (5): 754-7 (1975)]**PEER REVIEWED**

METHYLHYDRAZINE WAS TESTED FOR SYNERGISM IN PROMOTING IN VITRO ONCOGENIC TRANSFORMATION OF SWISS MOUSE 3T3 CELLS BY HERPES SIMPLEX TYPE 2 VIRUS (HSV-2). METHYLHYDRAZINE ENHANCED LEVEL OF ONCOGENIC TRANSFORMATION APPROX 2-FOLD.
[JOHNSON FB; US NTIS, AD REP; (AD-A054595): 16 PP (1978)]**PEER REVIEWED**

Several inhibitors of the FAD-containing monooxygenase (FAD-MO) system from rat liver microsomes (imipramine, chloropromazine, mercaptoethylamine, dithiothreitol, naphthylthiourea, phenylthiocarbamide) and one inhibitor of the liver microsomal cytochrome p450-mediated biotransformations, were tested as possible inhibitors of monomethylhydrazine (MMH) biotransformation to carbon dioxide and to reactive metabolites that bind covalently to nucleic acids and proteins. Results confirm previous suggestions that both FAD-containing monooxygenase system and p450 are involved in monomethylhydrazine metabolism to carbon dioxide and suggest a similar participation of both systems for production of reactive metabolites interacting wth macromolecules.
[Diaz Gomez MI, Castro JA; Arch Toxicol 59 (1): 64-6 (1986)]**PEER REVIEWED**

EXPTL USE: SINGLE SC INJECTIONS OF SUBSTITUTED HYDRAZINES WERE GIVEN ALONE & JOINTLY WITH PYRIDOXINE HYDROCHLORIDE TO SWISS MICE. THE CONVULSIVE, TOXIC & LETHAL EFFECTS OF METHYLHYDRAZINE WERE SUCCESSFULLY PREVENTED BY ADMIN OF PYRIDOXINE HYDROCHLORIDE BEFORE &/OR AFTER INJECTION.
[TOTH B, ERICKSON J; TOXICOLOGY 7 (1): 31-6 (1977)]**PEER REVIEWED**

EXPTL USE: THE EFFECTIVENESS OF MUSCIMOL, DIAZEPAM, & PYRIDOXINE & CERTAIN COMBINATIONS OF THESE COMPOUNDS AGAINST CONVULSIONS INDUCED BY MONOMETHYLHYDRAZINE WAS EXAM IN MICE. ALL DRUGS HAD A PROTECTIVE EFFECT BUT COMBINATIONS CONTAINING DIAZEPAM & EITHER PYRIDOXINE OR MUSCIMOL WERE THE MOST EFFECTIVE ANTAGONISTS TO MONOMETHYLHYDRAZINE POISONING.
[GEORGE ME ET AL; TOXICOL APPL PHARMACOL 63 (2): 201-8 (1982)]**PEER REVIEWED**

Repeated, large doses of pyridoxine can control methyl hydrazine-induced convulsions ... The recommended dose of pyridoxine can be reduced when concurrent admin of diazepam is employed.
[American Conference of Governmental Industrial Hygienists, Inc. Documentation of the Threshold Limit Values and Biological Exposure Indices. 6th ed. Volumes I,II, III. Cincinnati, OH: ACGIH, 1991. 1010]**PEER REVIEWED**

Pharmacology:

Interactions:

ADMIN OF METHYLHYDRAZINE TO MICE DECR SURVIVAL OF ANIMALS AFTER X-IRRADIATION, INHIBITED GROWTH OF EHRLICH ASCITES TUMOR, & INCR NUMBER OF CELLS WITH CHROMOSOME ABERRATIONS. DECR IN THE SH LEVEL WAS SUGGESTED AS RESPONSIBLE FOR RADIOSENSITIZING ACTIVITY.
[LE XUAN TU ET AL; RADIOBIOLOGIYA 15 (5): 754-7 (1975)]**PEER REVIEWED**

METHYLHYDRAZINE WAS TESTED FOR SYNERGISM IN PROMOTING IN VITRO ONCOGENIC TRANSFORMATION OF SWISS MOUSE 3T3 CELLS BY HERPES SIMPLEX TYPE 2 VIRUS (HSV-2). METHYLHYDRAZINE ENHANCED LEVEL OF ONCOGENIC TRANSFORMATION APPROX 2-FOLD.
[JOHNSON FB; US NTIS, AD REP; (AD-A054595): 16 PP (1978)]**PEER REVIEWED**

Several inhibitors of the FAD-containing monooxygenase (FAD-MO) system from rat liver microsomes (imipramine, chloropromazine, mercaptoethylamine, dithiothreitol, naphthylthiourea, phenylthiocarbamide) and one inhibitor of the liver microsomal cytochrome p450-mediated biotransformations, were tested as possible inhibitors of monomethylhydrazine (MMH) biotransformation to carbon dioxide and to reactive metabolites that bind covalently to nucleic acids and proteins. Results confirm previous suggestions that both FAD-containing monooxygenase system and p450 are involved in monomethylhydrazine metabolism to carbon dioxide and suggest a similar participation of both systems for production of reactive metabolites interacting wth macromolecules.
[Diaz Gomez MI, Castro JA; Arch Toxicol 59 (1): 64-6 (1986)]**PEER REVIEWED**

EXPTL USE: SINGLE SC INJECTIONS OF SUBSTITUTED HYDRAZINES WERE GIVEN ALONE & JOINTLY WITH PYRIDOXINE HYDROCHLORIDE TO SWISS MICE. THE CONVULSIVE, TOXIC & LETHAL EFFECTS OF METHYLHYDRAZINE WERE SUCCESSFULLY PREVENTED BY ADMIN OF PYRIDOXINE HYDROCHLORIDE BEFORE &/OR AFTER INJECTION.
[TOTH B, ERICKSON J; TOXICOLOGY 7 (1): 31-6 (1977)]**PEER REVIEWED**

EXPTL USE: THE EFFECTIVENESS OF MUSCIMOL, DIAZEPAM, & PYRIDOXINE & CERTAIN COMBINATIONS OF THESE COMPOUNDS AGAINST CONVULSIONS INDUCED BY MONOMETHYLHYDRAZINE WAS EXAM IN MICE. ALL DRUGS HAD A PROTECTIVE EFFECT BUT COMBINATIONS CONTAINING DIAZEPAM & EITHER PYRIDOXINE OR MUSCIMOL WERE THE MOST EFFECTIVE ANTAGONISTS TO MONOMETHYLHYDRAZINE POISONING.
[GEORGE ME ET AL; TOXICOL APPL PHARMACOL 63 (2): 201-8 (1982)]**PEER REVIEWED**

Repeated, large doses of pyridoxine can control methyl hydrazine-induced convulsions ... The recommended dose of pyridoxine can be reduced when concurrent admin of diazepam is employed.
[American Conference of Governmental Industrial Hygienists, Inc. Documentation of the Threshold Limit Values and Biological Exposure Indices. 6th ed. Volumes I,II, III. Cincinnati, OH: ACGIH, 1991. 1010]**PEER REVIEWED**

Environmental Fate & Exposure:

Environmental Fate/Exposure Summary:

Methylhydrazine's production and use as a rocket fuel may result in its direct release to the environment during refueling and transfer operations. It may also be released in various waste streams during the production or use of this compound as an intermediate in chemical synthesis and as a solvent. If released to the atmosphere, methylhydrazine will exist solely in the vapor phase in the ambient atmosphere, based on a measured vapor pressure of 50 mm Hg at 25 deg C. Vapor-phase methylhydrazine is degraded in the atmosphere by reaction with photochemically-produced hydroxyl radicals and ozone with estimated half-lives of about 6 hours and 1-12 minutes, respectively. Both vapor phase methylhydrazine and methylhydrazine dissolved in aerosols are expected to react rapidly with ozone. An estimated Koc value of 6 suggests that methylhydrazine will have very high mobility in soil. Hydrazines are weak bases and should exist predominantly in their protonated form at pH values below their pKa value. A positive charge on the hydrazine could either increase or decrease the adsorption capacity of this compound depending on the soil and pH. Some chemical decomposition of methylhydrazine was reported in soil. Volatilization from moist soil surfaces is not expected to occur based on an estimated Henry's Law constant of 3.2X10-8 atm-cu m/mole. Volatilization from dry soil surfaces may be significant given the vapor pressure of this compound. Methyl hydrazine may also undergo direct photolysis on soil and water surfaces since hydrazines strongly absorb UV light in the environmentally significant range. Based on limited data, methylhydrazine may biodegrade in soil and water under aerobic conditions. In water, methylhydrazine is not expected to adsorb to sediment and particulate matter based on its Koc value although it may adsorb strongly to clay particulates and organic matter based on soil studies. This compound should not volatilize from water surfaces given its estimated Henry's Law constant. Estimated half-lives of methylhydrazine present at 9.5 mM in pond and sea water are 18.0 and 24.1 days, respectively, and at 19.0 mM are 13.1 days in both pond and sea water. Release to water is expected to result in oxidation by dissolved oxygen, especially at high pH values; the half-life of the reaction between methylhydrazine and dissolved oxygen in water is about 2 hr at 30 deg C and pH 9.16. Bioconcentration in aquatic organisms should be low based on an estimated BCF value of 0.1. Occupational exposure may occur through inhalation or dermal contact at sites where methylhydrazine is produced or used. The general population may be exposed to methylhydrazine via dermal contact with vapors and products containing methylhydrazine. (SRC)
**PEER REVIEWED**

Probable Routes of Human Exposure:

Monomethylhydrazine ... is a decomposition product of the mushroom toxin, gyromitrin (Gyromitra esculenta) ... /when/ generated in vivo is believed to be responsible for the toxicity of gyromitrin.
[Gosselin, R.E., R.P. Smith, H.C. Hodge. Clinical Toxicology of Commercial Products. 5th ed. Baltimore: Williams and Wilkins, 1984.,p. II-247]**PEER REVIEWED**

Human exposure to methylhydrazine most likely results from its use as a component of aerospace propellants. NIOSH (NOES Survey 1981-1983) has estimated that 1,473 workers (230 of these are female) are exposed to methylhydrazine in the USA(1). The general population may be exposed to methylhydrazine via dermal contact with vapors and other products containing methylhydrazine(SRC).
[(1) NIOSH: National Occupational Exposure Survey (NOES) (1983)]**PEER REVIEWED**

Natural Pollution Sources:

It has been found in nature in an edible mushroom Gyrimitia esculenta.
[Clayton, G. D. and F. E. Clayton (eds.). Patty's Industrial Hygiene and Toxicology: Volume 2A, 2B, 2C: Toxicology. 3rd ed. New York: John Wiley Sons, 1981-1982. 2801]**PEER REVIEWED**

Artificial Pollution Sources:

Methylhydrazine's use in rocket fuel, as an intermediate in chemical synthesis(1) and as a solvent(2), may result in environmental release in a variety of waste streams(SRC). Methylhydrazine's production and use as a rocket fuel may result in its direct release to the environment during refueling and transfer operations(3).
[(1) Budavari S; The Merck Index - Encyclopedia of Chemicals, Drugs, and Biologicals. 12th Ed. Rahway, NJ: Merck and Co., Inc. p. 1039 (1996) (2) Lewis RJ; Hawley's Condensed Chemical Dictionary. 12th ed. NY, NY: Van Nostrand Reinhold Co. p. 770 (1991) (3) Judeikis HS, Damschen DE; Amer Chem Soc 186th Mtg Preprints Div Environ Chem 23: 281 (1983)]**PEER REVIEWED**

Environmental Fate:

TERRESTRIAL FATE: Based on a recommended classification scheme(1), an estimated Koc value of 6(SRC), determined from a measured log Kow(2) and a recommended regression-derived equation(3), indicates that methylhydrazine will have very high mobility in soil(SRC). Hydrazines are weak bases and should exist predominantly in their protonated form at pH values below their pKa value. A positive charge on the hydrazine could either increase or decrease the adsorption capacity of this compound depending on the soil and pH(SRC). Of the initial amount of methylhydrazine in sand, Vandenburg Air Force Base (VAFB) soil (99.1% sand, 0.4% clay, pH 6.1), organic soil (96.1% sand, 1% clay, 1% carbon, pH 6.4) and clay (69.3% sand, 27.95% clay, pH 3.7) samples, 0%, 5%, 20%, and 8%, respectively, was possibly degraded in less than 1 hour (mainly due to chemical decomposition)(4). Methylhydrazine may decompose in soils high in organic carbon and clay and tightly adsorb to clay soils; it may, however, leach from sandy soils(4). Methylhydrazine's measured value for vapor pressure, 50 mm Hg(5), indicates that volatilization from dry soil surfaces should be significant although adsorption to clay soils and soils containing organic matter may attenuate the rate of this process(SRC). Volatilization from moist soil surfaces is not expected based on the estimated Henry's Law constant, 3.2X10-8(6,SRC), for this compound(SRC). Based on limited data, it is possible that this compound may biodegrade in soil(7,SRC).
[(1) Swann RL et al; Res Rev 85: 23 (1983) (2) Hansch C et al; Exploring QSAR. Hydrophobic, Electronic, and Steric Constants. ACS Prof Ref Book. Amer Chem Soc, Washington, DC. p. 3 (1995) (3) Lyman WJ et al; Handbook of Chemical Property Estimation Methods. Washington DC: Amer Chem Soc pp. 4-9 (1990) (4) Braun BA, Zirrolli JA; Environ Fate of Hydrazine Fuels in Aqueous and Soil Environ, Air Force Report No. ESL-TR-82-45 NTIS AD-A125813 (1983) (5) Boublik T et al; The Vapor Pressures of Pure Substances: Selected Values of the Temperature Dependence of the Vapor Pressures of Some Pure Substances in the Normal and Low Pressure Region Elsevier Sci Publ Vol.17 Amsterdam, Netherlands (1984) (6) Meylan WM, Howard PH; Environ Toxicol Chem 10: 1283-93 (1991) (7) Wachinski AM, Farmwald JA; The Toxicity and Biodegradability of Hydrazine Wastewaters Treated With UV-Chlorinolysis. Final Report December 1978-February 1979. Eng Serv Lab, Air Force Eng Serv Cent, Tyndall AFB, FL USA, AFESC/ESL/ESL-TR-80-31; AD-AO94 187 (1980)]**PEER REVIEWED**

AQUATIC FATE: The estimated half-lives of methylhydrazine present at 9.5 mM in pond and sea water are 18.0 and 24.1 days, respectively, and at 19.0 mM are 13.1 days in both pond and sea water(1). The half-life of the reaction between methylhydrazine and dissolved oxygen in water is about 2 hr at 30 deg C and pH 9.16(2). Based on a recommended classification scheme(3), an estimated Koc value of 6(SRC), determined from a measured log Kow(4) and a recommended regression-derived equation(3), indicates that methylhydrazine should not adsorb to suspended solids and sediment in water(SRC). Based on results from soil studies, however, this compound may adsorb strongly to clay particles and organic matter in water(1). Methylhydrazine is not expected to volatilize from water surfaces(3,SRC) based on an estimated Henry's Law constant of 3.2X10-8 atm-cu m/mole(SRC), developed using a fragment constant estimation method(5). According to a classification scheme(6), an estimated BCF value of 0.1(3,SRC), from a measured log Kow(4), suggests that bioconcentration in aquatic organisms is low(SRC). Based on limited data, it is possible that this compound may biodegrade in water(7,SRC).
[(1) Braun BA, Zirrolli JA; Environ Fate of Hydrazine Fuels in Aqueous and Soil Environments, Air Force Report No. ESL-TR-82-45 NTIS AD-A125813 (1983) (2) Banerjee S et al; Chemosphere 13: 549-59 (1984) (3) Lyman WJ et al; Handbook of Chemical Property Estimation Methods. Washington DC: Amer Chem Soc pp. 4-9, 5-4, 5-10, 15-1 to 15-29 (1990) (4) Hansch C et al; Exploring QSAR. Hydrophobic, Electronic, and Steric Constants. ACS Prof Ref Book. Amer Chem Soc, Washington, DC. p. 3 (1995) (5) Meylan WM, Howard PH; Environ Toxicol Chem 10: 1283-93 (1991) (6) Franke C et al; Chemosphere 29: 1501-14 (1994) (7) Wachinski AM, Farmwald JA; The Toxicity and Biodegradability of Hydrazine Wastewaters Treated With UV-Chlorinolysis. Final Report December 1978-February 1979. Eng Serv Lab, Air Force Eng Serv Cent, Tyndall AFB, FL USA, AFESC/ESL/ESL-TR-80-31; AD-AO94 187 (1980)]**PEER REVIEWED**

ATMOSPHERIC FATE: According to a model of gas/particle partitioning of semivolatile organic compounds in the atmosphere(1), methylhydrazine, which has a measured vapor pressure of 50 mm Hg at 25 deg C(2), will exist solely as a vapor in the ambient atmosphere. Vapor-phase methylhydrazine is degraded in the atmosphere by reaction with photochemically-produced hydroxyl radicals(SRC); the half-life for this reaction in air is estimated to be about 6 hours(3,SRC). Assuming an ozone concentration of 7X10+11 molecules/cu cm, a maximum half life of about 3.3 min for the reaction of methylhydrazine with ozone was estimated from a minimum rate constant of 5X10-15 cu cm/molecule sec(4,SRC). The half life for the reaction between ozone and methylhydrazine was estimated to be <1 min during ozone pollution episodes and <12 min in the 'natural' troposphere(5). Reaction of methylhydrazine with ozone is expected to be the predominant fate of methylhydrazine in the atmosphere(SRC).
[(1) Bidleman TF; Environ Sci Technol 22: 361-367 (1988) (2) Boublik T et al; The Vapor Pressures of Pure Substances: Selected Values of the Temperature Dependence of the Vapor Pressures of Some Pure Substances in the Normal and Low Pressure Region Elsevier Sci Publ Vol.17 Amsterdam, Netherlands (1984) (3) Atkinson R; Kinetics and Mechanisms of the Gas-Phase Reactions of the Hydroxyl Radical With Organic Compounds. J Phys Chem Ref Data. Monograph Nol 1. (1989) (4) Tuazon EC et al; Atmospheric Reaction Mechanisms of Amine Fuels NTIS AD-A118267 (1982) (5) Tuazon EC et al; Environ Sci Technol 15: 823-8 (1981)]**PEER REVIEWED**

Environmental Biodegradation:

No data were available, but the toxicity of methylhydrazine to microbial species was found to be sufficiently high to prevent its degradation by biological waste treatment(1). Large amounts of methylhydrazine, such as might be released from a spill, are not expected to biodegrade. However, biodegradation of lower methylhydrazine concn may occur(SRC). Methylhydrazine at 500 mg/l, present in a wastewater mixture of hydrazine compounds, was incubated with an inoculum prepared from a trickling filter plant; following a 24 hour lag period, this mixture of compounds was biodegraded as measured by oxygen uptake(2). No specific information on the fate of methylhydrazine alone was available(2).
[(1) Kane DA, Williamson KJ; Arch Environ Contam Toxicol 12: 447-53 (1983) (2) Wachinski AM, Farmwald JA; The Toxicity and Biodegradability of Hydrazine Wastewaters Treated With UV-Chlorinolysis. Final Report December 1978-February 1979. Eng Serv Lab, Air Force Eng Serv Cent, Tyndall AFB, FL USA, AFESC/ESL/ESL-TR-80-31; AD-AO94 187 (1980)]**PEER REVIEWED**

Environmental Abiotic Degradation:

The rate constant for the vapor-phase reaction of methylhydrazine with photochemically-produced hydroxyl radicals has been measured as 6.50X10-11 cu cm/molecule-sec at 25 deg C(1). This corresponds to an atmospheric half-life of about 6 hours at an atmospheric concentration of 5X10+5 hydroxyl radicals per cu cm(1,SRC). Dark decay of 11.5 ppm methylhydrazine in a 6400 l chamber at 10% relative humidity (RH) and 24 deg C proceeded with a half life of 19.8 hr(2). Dark decay in a 3800 l chamber of 11.5 ppm methylhydrazine at 10% RH and 24 deg C proceeded with a half life of 49.8 hr and 10.3 ppm methylhydrazine at 17% RH and 22 deg C proceeded with a half life of 30.1 hr(2). The products were ammonia and methyldiazene. Ammonia accounted for only 2% and 4% of the methylhydrazine lost in dry and humidified air, respectively(2). The estimated concentration of methyldiazene in the 3800 l chamber experiments was about 0.3 ppm(2). A minimum reaction rate of about 5X10-15 cu cm/molecule sec was obtained for the reaction between methylhydrazine and ozone in a large chamber with 14-28% RH and from 22-24 deg C(2). Assuming an ozone concentration of 7X10+11 molecules/cu cm, the maximum half-life for the reaction of methylhydrazine with ozone is about 3.3 min(SRC). Major products observed were methylhydroperoxide, methyldiazene, formaldehyde, diazomethane and hydrogen peroxide(2). The half-life for the reaction between ozone and methylhydrazine was estimated to be < 1 min during ozone pollution episodes and < 12 min in the 'natural' troposphere(3). The upper limit for the rate of reaction of methylhydrazine with nitrogen dioxide is about 1.4X10-18 cu cm/molecule sec(2). Nitrous oxide does not react significantly with methylhydrazine(2). The lifetime of methylhydrazine in aerosols upon exposure to ozone is about 1 min(4). The aqueous oxidation of methylhydrazine results in methanol, nitromethane and nitrosodimethylamine(4). At a pH of 9.16 and 30 deg C, the first order rate constant for the reaction between dissolved oxygen and methylhydrazine is 5.6X10-3 1/min giving a half-life of about 2 hr(SRC,5). Methyl hydrazine may also undergo direct photolysis on soil and water surfaces since hydrazines strongly absorb UV light in the environmentally significant range(SRC).
[(1) Atkinson R; Kinetics and Mechanisms of the Gas-Phase Reactions of the Hydroxyl Radical With Organic Compounds. J Phys Chem Ref Data. Monograph Nol 1 (1989) (2) Tuazon EC et al; Atmospheric Reaction Mechanisms of Amine Fuels NTIS AD-A118267 (1982) (3) Tuazon EC et al; Environ Sci Technol 15: 823-8 (1981) (4) Judeikis HS, Damschen DE; Amer Chem Soc 186th Mtg Preprints Div Environ Chem 23: 281 (1983) (5) Banerjee S et al; Chemosphere 13: 549-59 (1984)]**PEER REVIEWED**

Environmental Bioconcentration:

An estimated BCF value of 0.1 was calculated for methylhydrazine(SRC), using a measured log Kow of -1.05(1) and a recommended regression-derived equation(2). According to a classification scheme(3), this BCF value suggests that bioconcentration in aquatic organisms is low(SRC).
[(1) Hansch C et al; Exploring QSAR. Hydrophobic, Electronic, and Steric Constants. ACS Prof Ref Book. Washington, DC: Amer Chem Soc, p. 3 (1995) (2) Lyman WJ et al; Handbook of Chemical Property Estimation Methods. Washington DC: Amer Chem Soc pp. 5-4, 5-10 (1990) (3) Franke C et al; Chemosphere 29: 1501-14 (1994)]**PEER REVIEWED**

Soil Adsorption/Mobility:

Of the initial amount of methylhydrazine in sand, Vandenburg Air Force Base (VAFB) soil (99.1% sand, 0.4% clay, pH 6.1), organic soil (96.1% sand, 1% clay, 1% carbon, pH 6.4) and clay (69.3% sand, 27.95% clay, pH 3.7), 3%, 46%, 26%, and 64% was adsorbed, respectively(1). Passage of 2 liters of distilled, deionized water through columns containing sand, VAFB soil, organic soil and clay (10% clay plus 90% pure sand) treated with 10 ml of a 0.1 v/v solution of methylhydrazine resulted in 86.9%, 5.5%, 6.5%, 6.3% recovery of methylhydrazine, respectively(1). Based on a log Kow of -1.05(2), a Koc of 6 for methylhydrazine has been calculated from a regression-derived equation(3,SRC). According to a recommended classification scheme(3), this estimated Koc value suggests that methylhydrazine has very high mobility in soil(SRC).
[(1) Braun BA, Zirrolli JA; Environ Fate of Hydrazine Fuels in Aqueous and Soil Environments, Air Force Report No. ESL-TR-82-45 NTIS AD-A125813 (1983) (2) Hansch C et al; Exploring QSAR. Hydrophobic, Electronic, and Steric Constants. ACS Prof Ref Book. Amer Chem Soc, Washington, DC. p. 3 (1995) (3) Lyman WJ et al; Handbook of Chemical Property Estimation Methods NY: McGraw-Hill p. 4-9 (1982) (4) Swann RL et al; Res Rev 85: 16-28 (1983)]**PEER REVIEWED**

Volatilization from Water/Soil:

The Henry's Law constant for methylhydrazine is estimated as 3.2X10-8 atm-cu m/mole(SRC) using a fragment constant estimation method(1). This value indicates that methylhydrazine will be essentially nonvolatile from water surfaces(2,SRC). Methylhydrazine's measured value for vapor pressure, 50 mm Hg at 25 deg C(3) indicates that volatilization from dry soil surfaces should be significant although adsorption to clay soils and soils containing organic matter may attenuate the rate of this process(SRC). Volatilization from moist soil surfaces is not expected based on the estimated Henry's Law constant(1,SRC) for this compound(SRC).
[(1) Meylan WM, Howard PH; Environ Toxicol Chem 10: 1283-93 (1991) (2) Lyman WJ et al; Handbook of Chemical Property Estimation Methods. Washington DC: Amer Chem Soc pp. 15-1 to 15-29 (1990) (3) Boublik T et al; The Vapor Pressures of Pure Substances: Selected Values of the Temperature Dependence of the Vapor Pressures of Some Pure Substances in the Normal and Low Pressure Region Elsevier Sci Publ Vol.17 Amsterdam, Netherlands (1984)]**PEER REVIEWED**

Environmental Standards & Regulations:

CERCLA Reportable Quantities:

Persons in charge of vessels or facilities are required to notify the National Response Center (NRC) immediately, when there is a release of this designated hazardous substance, in an amount equal to or greater than its reportable quantity of 10 lb or 4.54 kg. The toll free number of the NRC is (800) 424-8802; In the Washington D.C. metropolitan area (202) 426-2675. The rule for determining when notification is required is stated in 40 CFR 302.4 (section IV. D.3.b).
[40 CFR 302.4 (7/1/95)]**PEER REVIEWED**

Releases of CERCLA hazardous substances are subject to the release reporting requirement of CERCLA section 103, codified at 40 CFR part 302, in addition to the requirements of 40 CFR part 355. Methyl hydrazine is an extremely hazardous substance (EHS) subject to reporting requirements when stored in amounts in excess of its threshold planning quantity (TPQ) of 500 lbs.
[40 CFR 355 (7/1/97)]**QC REVIEWED**

RCRA Requirements:

P068; As stipulated in 40 CFR 261.33, when methyl hydrazine, as a commercial chemical product or manufacturing chemical intermediate or an off-specification commercial chemical product or a manufacturing chemical intermediate, becomes a waste, it must be managed according to federal and/or state hazardous waste regulations. Also defined as a hazardous waste is any container or inner liner used to hold this waste or any residue, contaminated soil, water, or other debris resulting from the cleanup of a spill, into water or on dry land, of this waste. Generators of small quantities of this waste may qualify for partial exclusion from hazardous waste regulations (40 CFR 261.5(e)).
[40 CFR 261.33 (7/1/95)]**PEER REVIEWED**

Atmospheric Standards:

Listed as a hazardous air pollutant (HAP) generally known or suspected to cause serious health problems. The Clean Air Act, as amended in 1990, directs EPA to set standards requiring major sources to sharply reduce routine emissions of toxic pollutants. EPA is required to establish and phase in specific performance based standards for all air emission sources that emit one or more of the listed pollutants. Methyl hydrazine is included on this list.
[Clean Air Act as amended in 1990, Sect. 112 (b) (1) Public Law 101-549 Nov. 15, 1990]**QC REVIEWED**

State Drinking Water Guidelines:

(FL) FLORIDA 10 ug/l
[USEPA/Office of Water; Federal-State Toxicology and Risk Analysis Committee (FSTRAC). Summary of State and Federal Drinking Water Standards and Guidelines (11/93)] **QC REVIEWED**

Chemical/Physical Properties:

Molecular Formula:

C-H6-N2
[The Merck Index. 10th ed. Rahway, New Jersey: Merck Co., Inc., 1983. 872]**PEER REVIEWED**

Molecular Weight:

46.07
[Lide, D.R. (ed.). CRC Handbook of Chemistry and Physics. 76th ed. Boca Raton, FL: CRC Press Inc., 1995-1996.,p. 3-197]**PEER REVIEWED**

Color/Form:

Clear liquid
[Budavari, S. (ed.). The Merck Index - An Encyclopedia of Chemicals, Drugs, and Biologicals. Whitehouse Station, NJ: Merck and Co., Inc., 1996. 1039]**PEER REVIEWED**

Fuming, colorless liquid.
[NIOSH. NIOSH Pocket Guide to Chemical Hazards. DHHS (NIOSH) Publication No. 94-116. Washington, D.C.: U.S. Government Printing Office, June 1994. 210]**PEER REVIEWED**

Odor:

ODOR CHARACTERISTIC OF SHORT CHAIN, ORGANIC AMINES
[Budavari, S. (ed.). The Merck Index - An Encyclopedia of Chemicals, Drugs, and Biologicals. Whitehouse Station, NJ: Merck and Co., Inc., 1996. 1039]**PEER REVIEWED**

Ammonia-like odor.
[NIOSH. NIOSH Pocket Guide to Chemical Hazards. DHHS (NIOSH) Publication No. 94-116. Washington, D.C.: U.S. Government Printing Office, June 1994. 210]**PEER REVIEWED**

Boiling Point:

87.5 DEG C
[Lide, D.R. (ed.). CRC Handbook of Chemistry and Physics. 76th ed. Boca Raton, FL: CRC Press Inc., 1995-1996.,p. 3-197]**PEER REVIEWED**

Melting Point:

-52.4 DEG C
[Lide, D.R. (ed.). CRC Handbook of Chemistry and Physics. 76th ed. Boca Raton, FL: CRC Press Inc., 1995-1996.,p. 3-197]**PEER REVIEWED**

Critical Temperature & Pressure:

CRITICAL TEMPERATURE: 594 DEG F= 312, DEG C= 585 DEG K; CRITICAL PRESSURE: 1,195 PSIA = 81.3 ATM = 8.25 MN/SQ M
[U.S. Coast Guard, Department of Transportation. CHRIS - Hazardous Chemical Data. Volume II. Washington, D.C.: U.S. Government Printing Office, 1984-5.]**PEER REVIEWED**

Density/Specific Gravity:

0.874 @ 25 DEG C
[Budavari, S. (ed.). The Merck Index - An Encyclopedia of Chemicals, Drugs, and Biologicals. Whitehouse Station, NJ: Merck and Co., Inc., 1996. 1039]**PEER REVIEWED**

Heat of Combustion:

-12,178 BTU/LB = -6,766 CAL/G = -283.1X10+5 J/KG
[U.S. Coast Guard, Department of Transportation. CHRIS - Hazardous Chemical Data. Volume II. Washington, D.C.: U.S. Government Printing Office, 1984-5.]**PEER REVIEWED**

Heat of Vaporization:

376 BTU/LB= 209 CAL/G= 8.75X10+5 J/KG
[U.S. Coast Guard, Department of Transportation. CHRIS - Hazardous Chemical Data. Volume II. Washington, D.C.: U.S. Government Printing Office, 1984-5.]**PEER REVIEWED**

Octanol/Water Partition Coefficient:

Log Kow= -1.05
[Hansch, C., Leo, A., D. Hoekman. Exploring QSAR - Hydrophobic, Electronic, and Steric Constants. Washington, DC: American Chemical Society., 1995. 3]**PEER REVIEWED**

pH:

MILDLY ALKALINE BASE
[Budavari, S. (ed.). The Merck Index - An Encyclopedia of Chemicals, Drugs, and Biologicals. Whitehouse Station, NJ: Merck and Co., Inc., 1996. 1039]**PEER REVIEWED**

Solubilities:

>10% in ethyl ether
[Weast, R.C. and M.J. Astle. CRC Handbook of Data on Organic Compounds. Volumes I and II. Boca Raton, FL: CRC Press Inc. 1985.,p. V1 747]**PEER REVIEWED**

>10% in ethanol
[Weast, R.C. and M.J. Astle. CRC Handbook of Data on Organic Compounds. Volumes I and II. Boca Raton, FL: CRC Press Inc. 1985.,p. V1 747]**PEER REVIEWED**

>10% in water
[Weast, R.C. and M.J. Astle. CRC Handbook of Data on Organic Compounds. Volumes I and II. Boca Raton, FL: CRC Press Inc. 1985.,p. V1 747]**PEER REVIEWED**

SOL IN PETROLEUM ETHER
[Dean, J.A. Handbook of Organic Chemistry. New York, NY: McGraw-Hill Book Co., 1987.,p. 1-292]**PEER REVIEWED**

MISCIBLE WITH HYDRAZINE AND WATER, LOW MOL WT MONOHYDRIC ALCOHOLS; SOL IN HYDROCARBONS
[Budavari, S. (ed.). The Merck Index - An Encyclopedia of Chemicals, Drugs, and Biologicals. Whitehouse Station, NJ: Merck and Co., Inc., 1996. 1039]**PEER REVIEWED**

Miscible in alcohol; soluble in water, ether, and carbon tetrachloride.
[Lide, D.R. (ed.). CRC Handbook of Chemistry and Physics. 76th ed. Boca Raton, FL: CRC Press Inc., 1995-1996.,p. 3-197]**PEER REVIEWED**

Spectral Properties:

IR PRISM: 7650 (Sadtler Research Laboratories Prism Collection)
[Weast, R.C. and M.J. Astle. CRC Handbook of Data on Organic Compounds. Volumes I and II. Boca Raton, FL: CRC Press Inc. 1985.,p. V1 747]**PEER REVIEWED**

NMR: 6865 (Sadtler Research Laboratories Spectral Collection)
[Weast, R.C. and M.J. Astle. CRC Handbook of Data on Organic Compounds. Volumes I and II. Boca Raton, FL: CRC Press Inc. 1985.,p. V1 747]**PEER REVIEWED**

MASS: 4 (National Bureau of Standards EPA-NIH Mass Spectra Data Base, NSRDS-NBS-63)
[Weast, R.C. and M.J. Astle. CRC Handbook of Data on Organic Compounds. Volumes I and II. Boca Raton, FL: CRC Press Inc. 1985.,p. V1 747]**PEER REVIEWED**

Index of refraction: 1.4325 @ 20 deg C/d
[Lide, D.R. (ed.). CRC Handbook of Chemistry and Physics. 76th ed. Boca Raton, FL: CRC Press Inc., 1995-1996.,p. 3-197]**PEER REVIEWED**

Surface Tension:

34.3 dynes/cm= 0.0343 N/m at 20 deg C (liquid)
[U.S. Coast Guard, Department of Transportation. CHRIS - Hazardous Chemical Data. Volume II. Washington, D.C.: U.S. Government Printing Office, 1984-5.]**PEER REVIEWED**

Vapor Density:

1.6 (AIR= 1)
[Sax, N.I. Dangerous Properties of Industrial Materials. 6th ed. New York, NY: Van Nostrand Reinhold, 1984. 1858]**PEER REVIEWED**

Vapor Pressure:

50 mm Hg at 25 deg C
[Boublik T et al; The Vapor Pressures of Pure Substances: Selected Values of the Temperature Dependence of the Vapor Pressures of Some Pure Substances in the Normal and Low Pressure Region Elsevier Sci Publ Vol.17 Amsterdam, Netherlands (1984)]**PEER REVIEWED**

Viscosity:

0.771 millipascal second @ 25 deg C
[Kirk-Othmer Encyclopedia of Chemical Technology. 3rd ed., Volumes 1-26. New York, NY: John Wiley and Sons, 1978-1984.,p. V12 739 (1980)]**PEER REVIEWED**

Other Chemical/Physical Properties:

CONVERSION FACTORS: 1 MG/L= 532 PPM; 1 PPM= 1.88 MG/CU M
[Clayton, G. D. and F. E. Clayton (eds.). Patty's Industrial Hygiene and Toxicology: Volume 2A, 2B, 2C: Toxicology. 3rd ed. New York: John Wiley Sons, 1981-1982. 2795]**PEER REVIEWED**

HEAT CAPACITY AT 25 DEG C: 32.25 CAL/MOLE/DEG C; STRONG REDUCING AGENT
[The Merck Index. 10th ed. Rahway, New Jersey: Merck Co., Inc., 1983. 872]**PEER REVIEWED**

HYGROSCOPIC
[Sax, N.I. Dangerous Properties of Industrial Materials. 6th ed. New York, NY: Van Nostrand Reinhold, 1984. 1858]**PEER REVIEWED**

Heat of fusion: 10.42 kJ/mole; heat of formation: 53.97 kJ/mole; free energy of formation: 179.9 kJ/mole; entropy of formation: 165.9 J/mole/deg C
[Kirk-Othmer Encyclopedia of Chemical Technology. 3rd ed., Volumes 1-26. New York, NY: John Wiley and Sons, 1978-1984.,p. V12 739 (1980)]**PEER REVIEWED**

Ionization potential: 7.67 eV
[NIOSH. Pocket Guide to Chemical Hazards. 2nd Printing. DHHS (NIOSH) Publ. No. 85-114. Washington, D.C.: U.S. Dept. of Health and Human Services, NIOSH/Supt.of Documents, GPO, February 1987. 168]**PEER REVIEWED**

The kinetics of oxidation of methylhydrazine and 1,1-dimethylhydrazine by dissolved oxygen in water was measured at various acidities as a function of catalyst (cupric ion) concentration. In dilute solutions the oxidation occurred through a cupric ion catalyzed process and by an uncatalyzed step. The extent of formation of the carcinogen nitrosodimethylamine depended on the initial 1,1-dimethylhydrazine concentration. In dilute solutions nitrosodimethylamine was not formed, but in more concentrated solutions, nitrosodimethylamine formation increased with increasing 1,1-dimethylhydrazine content, reached a maximum at 60-80% 1,1-dimethylhydrazine (by volume) and then decreased. The nitrosodimethylamine yield appeared to approximately parallel the viscosity of the medium, and it was speculated that the factors which controlled viscosity may also have been responsible for governing nitrosodimethylamine formation.
[Banerjee S et al; Chemosphere 13 (4): 549-60 (1984)]**PEER REVIEWED**

Chemical Safety & Handling:

DOT Emergency Guidelines:

Health: Toxic; may be fatal if inhaled, ingested or absorbed through skin. Inhalation or contact with some of these materials will irritate or burn skin and eyes. Fire will produce irritating, corrosive and/or toxic gases. Vapors may cause dizziness or suffocation. Runoff from fire control or dilution water may cause pollution.
[U.S. Department of Transportation. 2000 Emergency Response Guidebook. RSPA P 5800.8 Edition. Washington, D.C: U.S. Government Printing Office, 2000,p. G-131]**QC REVIEWED**

Fire or explosion: Highly flammable: Will be easily ignited by heat, sparks or flames. Vapors may form explosive mixtures with air. Vapors may travel to source of ignition and flash back. Most vapors are heavier than air. They will spread along ground and collect in low or confined areas (sewers, basements, tanks). Vapor explosion and poison hazard indoors, outdoors or in sewers. Those substances designated with a "P" may polymerize explosively when heated or involved in a fire. Runoff to sewer may create fire or explosion hazard. Containers may explode when heated. Many liquids are lighter than water.
[U.S. Department of Transportation. 2000 Emergency Response Guidebook. RSPA P 5800.8 Edition. Washington, D.C: U.S. Government Printing Office, 2000,p. G-131]**QC REVIEWED**

Public safety: Call Emergency Response Telephone Number. ... Isolate spill or leak area immediately for at least 100 to 200 meters (330 to 660 feet) in all directions. Keep unauthorized personnel away. Stay upwind. Keep out of low areas. Ventilate closed spaces before entering.
[U.S. Department of Transportation. 2000 Emergency Response Guidebook. RSPA P 5800.8 Edition. Washington, D.C: U.S. Government Printing Office, 2000,p. G-131]**QC REVIEWED**

Protective clothing: Wear positive pressure self-contained breathing apparatus (SCBA). Wear chemical protective clothing which is specifically recommended by the manufacturer. It may provide little or no thermal protection. Structural firefighters' protective clothing provides limited protection in fire situations ONLY; it is not effective in spill situations.
[U.S. Department of Transportation. 2000 Emergency Response Guidebook. RSPA P 5800.8 Edition. Washington, D.C: U.S. Government Printing Office, 2000,p. G-131]**QC REVIEWED**

Evacuation: ... Fire: If tank, rail car or tank truck is involved in a fire, isolate for 800 meters (1/2 mile) in all directions; also, consider initial evacuation for 800 meters (1/2 mile) in all directions.
[U.S. Department of Transportation. 2000 Emergency Response Guidebook. RSPA P 5800.8 Edition. Washington, D.C: U.S. Government Printing Office, 2000,p. G-131]**QC REVIEWED**

Fire: CAUTION: All these products have a very low flash point. Use of water spray when fighting fire may be inefficient. Small fires: Dry chemical, CO2, water spray or alcohol-resistant foam. Large fires: Water spray, fog or alcohol-resistant foam. Move containers from fire area if you can do it without risk. Dike fire control water for later disposal; do not scatter the material. Use water spray or fog; do not use straight streams. Fire involving tanks or car/trailer loads: Fight fire from maximum distance or use unmanned hose holders or monitor nozzles. Cool containers with flooding quantities of water until well after fire is out. Withdraw immediately in case of rising sound from venting safety devices or discoloration of tank. ALWAYS stay away from tanks engulfed in fire. For massive fire use unmanned hose holders or monitor nozzles; if this is impossible, withdraw from area and let fire burn.
[U.S. Department of Transportation. 2000 Emergency Response Guidebook. RSPA P 5800.8 Edition. Washington, D.C: U.S. Government Printing Office, 2000,p. G-131]**QC REVIEWED**

Spill or leak: Fully encapsulating, vapor protective clothing should be worn for spills and leaks with no fire. ELIMINATE all ignition sources (no smoking, flares, sparks or flames in immediate area). All equipment used when handling the product must be grounded. Do not touch or walk through spilled material. Stop leak if you can do it without risk. Prevent entry into waterways, sewers, basements or confined areas. A vapor suppressing foam may be used to reduce vapors. Small spills: Absorb with earth, sand or other non-combustible material and transfer to containers for later disposal. Use clean non-sparking tools to collect absorbed material. Large spills: Dike far ahead of liquid spill for later disposal. Water spray may reduce vapor; but may not prevent ignition in closed spaces.
[U.S. Department of Transportation. 2000 Emergency Response Guidebook. RSPA P 5800.8 Edition. Washington, D.C: U.S. Government Printing Office, 2000,p. G-131]**QC REVIEWED**

First aid: Move victim to fresh air. Call 911 or emergency medical service. Apply artificial respiration if victim is not breathing. Do not use mouth-to-mouth method if victim ingested or inhaled the substance; induce artificial respiration with the aid of a pocket mask equipped with a one-way valve or other proper respiratory medical device. Administer oxygen if breathing is difficult. Remove and isolate contaminated clothing and shoes. In case of contact with substance, immediately flush skin or eyes with running water for at least 20 minutes. Wash skin with soap and water. Keep victim warm and quiet. Effects of exposure (inhalation, ingestion or skin contact) to substance may be delayed. Ensure that medical personnel are aware of the material(s) involved, and take precautions to protect themselves.
[U.S. Department of Transportation. 2000 Emergency Response Guidebook. RSPA P 5800.8 Edition. Washington, D.C: U.S. Government Printing Office, 2000,p. G-131]**QC REVIEWED**

Odor Threshold:

1.75 mg/cu m (low); 5.25 mg/cu m (high)
[Ruth JH; Am Ind Hyg Assoc J 47: A-142-51 (1986)]**PEER REVIEWED**

The warning properties (irritation & odor) of the hydrazines are probably sufficient to prevent acute poisoning from short exposures. However, in view of the chronic toxicity properties, the warning properties should not be considered adequate for prolonged exposures. They ... have median detectable odor levels of 1 to 10 ppm, but these levels are levels above all the TLVs adopted for hydrazines except phenylhydrazine. /Hydrazines/
[Clayton, G. D. and F. E. Clayton (eds.). Patty's Industrial Hygiene and Toxicology: Volume 2A, 2B, 2C: Toxicology. 3rd ed. New York: John Wiley Sons, 1981-1982. 2797]**PEER REVIEWED**

Skin, Eye and Respiratory Irritations:

Vapor is irritating to eyes, nose & throat.
[U.S. Coast Guard, Department of Transportation. CHRIS - Hazardous Chemical Data. Volume II. Washington, D.C.: U.S. Government Printing Office, 1984-5.]**PEER REVIEWED**

Skin irritation is pronounced with the propellant hydrazines ... /Hydrazine & derivatives/
[International Labour Office. Encyclopedia of Occupational Health and Safety. Vols. I&II. Geneva, Switzerland: International Labour Office, 1983. 1069]**PEER REVIEWED**

All hydrazines have similar toxic local effects due to their irritant properties. The vapor is highly irritating to the eyes, upper respiratory tract, & skin ... /Hydrazines/
[Sittig, M. Handbook of Toxic and Hazardous Chemicals and Carcinogens, 1985. 2nd ed. Park Ridge, NJ: Noyes Data Corporation, 1985. 502]**PEER REVIEWED**

Fire Potential:

DANGEROUS, WHEN EXPOSED TO HEAT OR FLAME.
[Sax, N.I. Dangerous Properties of Industrial Materials. 6th ed. New York, NY: Van Nostrand Reinhold, 1984. 1858]**PEER REVIEWED**

NFPA Hazard Classification:

Health: 4. 4= Materials that, on very short exposure, could cause death or major residual injury, including those that are too dangerous to be approached without specialized protective equipment. A few whiffs of the vapor or gas can cause death, or contact with the vapor or liquid may be fatal, if it penetrates the fire fighter's normal protective gear. The normal full protective clothing and breathing apparatus available to the typical fire fighter will not provide adequate protection against inhalation or skin contact with these materials.
[Fire Protection Guide to Hazardous Materials. 12 ed. Quincy, MA: National Fire Protection Association, 1997.,p. 49-89]**QC REVIEWED**

Flammability: 3. 3= Includes Class IB and IC flammable liquids and materials that can be easily ignited under almost all normal temp conditions. Water may be ineffective in controlling or extinguishing fires in such materials.
[Fire Protection Guide to Hazardous Materials. 12 ed. Quincy, MA: National Fire Protection Association, 1997.,p. 49-89]**QC REVIEWED**

Reactivity: 2. 2= This degree includes materials that are normally unstable and readily undergo violent chemical change, but are not capable of detonation. This includes materials that can undergo chemical change with rapid release of energy at normal temperatures and pressures and materials that can undergo violent chemical changes at elevated temperatures and pressures. This also includes materials that may react violently with water or that may form potentially explosive mixtures with water. In advanced or massive fires involving these materials, fire fighting should be done from a safe distance or from a protected location.
[Fire Protection Guide to Hazardous Materials. 12 ed. Quincy, MA: National Fire Protection Association, 1997.,p. 49-89]**QC REVIEWED**

Flammable Limits:

Lower flammable limit: 2.5% by volume; Upper flammable limit: 97% by volume
[Fire Protection Guide to Hazardous Materials. 12 ed. Quincy, MA: National Fire Protection Association, 1997.,p. 49-89]**QC REVIEWED**

Flash Point:

-8 deg C, 17 deg F (closed cup)
[Fire Protection Guide to Hazardous Materials. 12 ed. Quincy, MA: National Fire Protection Association, 1997.,p. 49-89]**QC REVIEWED**

Autoignition Temperature:

196 DEG C (385 DEG F)
[Fire Protection Guide to Hazardous Materials. 12 ed. Quincy, MA: National Fire Protection Association, 1997.,p. 49-89]**QC REVIEWED**

Fire Fighting Procedures:

If material on fire or involved in fire: Do not extinguish fire unless flow can be stopped. Use water in flooding quantities as fog. Cool all affected containers with flooding quantities of water. Apply water from as far a distance as possible. Solid streams of water may be ineffective. Use "alcohol" foam, dry chemical or carbon dioxide.
[Association of American Railroads. Emergency Handling of Hazardous Materials in Surface Transportation. Washington, DC: Association of American Railroads, Bureau of Explosives, 1994. 730]**PEER REVIEWED**

Toxic Combustion Products:

Toxic oxides of nitrogen are produced during combustion of this material.
[Association of American Railroads. Emergency Handling of Hazardous Materials in Surface Transportation. Washington, DC: Association of American Railroads, Bureau of Explosives, 1994. 730]**PEER REVIEWED**

Firefighting Hazards:

VAPORS ARE HEAVIER THAN AIR & MAY TRAVEL TO A SOURCE OF IGNITION & FLASH BACK.
[Fire Protection Guide to Hazardous Materials. 12 ed. Quincy, MA: National Fire Protection Association, 1997.,p. 49-89]**QC REVIEWED**

Prolonged exposure of the containers of the material to fire or heat may result in the spontaneous decomposition of the material & violent rupture of the container.
[Association of American Railroads. Emergency Handling of Hazardous Materials in Surface Transportation. Washington, D.C.: Assoc. of American Railroads,Hazardous Materials Systems (BOE), 1987. 465]**PEER REVIEWED**

Explosive Limits & Potential:

2.5 & 97% + OR - 2% BY VOL
[American Conference of Governmental Industrial Hygienists. Documentation of the Threshold Limit Values and Biological Exposure Indices. 5th ed. Cincinnati, OH:American Conference of Governmental Industrial Hygienists, 1986. 398]**PEER REVIEWED**

Ignites on contact with hydrogen peroxide or nitrogen dioxlde among other oxidants.
[Armour, M.A. Hazardous Laboratory Chemicals Disposal Guide. Boca Raton, FL: CRC Press Inc., 1991. 230]**PEER REVIEWED**

Hazardous Reactivities & Incompatibilities:

Reacts violently with oxidizing materials, oxygen, & peroxides; sometimes resulting in autoignition.
[Fire Protection Guide to Hazardous Materials. 12 ed. Quincy, MA: National Fire Protection Association, 1997.,p. 49-89]**QC REVIEWED**

Oxides of iron; copper; manganese; lead; copper alloys; porous materials such as earth, asbestos, wood & cloth; strong oxidizers such as fluorine & chlorine; nitric acid; hydrogen peroxide.
[NIOSH. NIOSH Pocket Guide to Chemical Hazards. DHHS (NIOSH) Publication No. 97-140. Washington, D.C. U.S. Government Printing Office, 1997. 210]**QC REVIEWED**

Spontaneous ignition may occur if in contact with oxidizing materials.
[Association of American Railroads. Emergency Handling of Hazardous Materials in Surface Transportation. Washington, DC: Association of American Railroads, Bureau of Explosives, 1994. 730]**PEER REVIEWED**

A powerful reducing agent & fuel, hypergolic with many oxidants such as dinitrogen tetraoxide or hydrogen peroxide.
[Bretherick, L. Handbook of Reactive Chemical Hazards. 4th ed. Boston, MA: Butterworth-Heinemann Ltd., 1990 179]**PEER REVIEWED**

Contact of dicyanofurazan, or its N-oxide (dicyanofuroxan), with hydrazine, mono or dimethylhydrazine ... is instantaneously explosive.
[Bretherick, L. Handbook of Reactive Chemical Hazards. 4th ed. Boston, MA: Butterworth-Heinemann Ltd., 1990 509]**PEER REVIEWED**

IGNITES SPONTANEOUSLY ON CONTACT WITH STRONG OXIDIZING AGENTS SUCH AS FLUORINE, CHLORINE TRIFLUORIDE, NITROGEN TETRAOXIDE, FUMING NITRIC ACID.
[The Merck Index. 10th ed. Rahway, New Jersey: Merck Co., Inc., 1983. 872]**PEER REVIEWED**

Immediately Dangerous to Life or Health:

NIOSH considers methyl hydrazine to be a potential occupational carcinogen.
[NIOSH. NIOSH Pocket Guide to Chemical Hazards. DHHS (NIOSH) Publication No. 97-140. Washington, D.C. U.S. Government Printing Office, 1997. 210]**QC REVIEWED**

Protective Equipment & Clothing:

Wear special protective clothing and positive pressure self-contained breathing apparatus.
[Fire Protection Guide to Hazardous Materials. 12 ed. Quincy, MA: National Fire Protection Association, 1997.,p. 49-89]**QC REVIEWED**

Breakthrough times greater than one hour reported by (normally) two or more testers for butyl rubber and polyvinyl chloride. Some data suggesting breakthrough times of approximately an hour for chlorinated polyethylene and viton.
[ACGIH; Guidelines Select of Chem Protect Clothing Volume #1 Field Guide p.56 (1983)]**PEER REVIEWED**

... VINYL COATED HAND PROTECTION, NATURAL OR RECLAIMED RUBBER PROTECTION, RUBBER APRONS, AND PLASTIC EYE AND FACE PROTECTION ... USED WHEN WORKING WITH SMALL QUANTITIES. WHERE POSSIBILITY OF GROSS SPLASHING EXISTS, FULL PROTECTIVE CLOTHING MADE OF RUBBER, NEOPRENE OR VINYL-COATED MATERIALS SHOULD BE WORN. FOR RESPIRATORY PROTECTION IN SITUATIONS WHERE RECOMMENDED TOLERANCE LIMITS ... EXCEEDED, RESPIRATORY PROTECTIVE EQUIPMENT SUCH AS APPROVED CANISTERS OR A GAS MASK OR SELF CONTAINED BREATHING APPARATUS MUST BE USED. /HYDRAZINE & DERIVATIVES/
[International Labour Office. Encyclopedia of Occupational Health and Safety. Vols. I&II. Geneva, Switzerland: International Labour Office, 1983. 1069]**PEER REVIEWED**

All systems or equipment containing the hydrazines shall be designed to minimize the possibility of vapor or aerosol inhalation, skin or eye contact, and spill or leaks; such as full face shields, goggles, and full body protection clothing, including gloves and boots. /Hydrazines/
[NIOSH; Criteria Document: Hydrazine p.7 (1978) DHEW Pub. NIOSH 78-172]**PEER REVIEWED**

Wear appropriate personal protective clothing to prevent skin contact.
[NIOSH. NIOSH Pocket Guide to Chemical Hazards. DHHS (NIOSH) Publication No. 97-140. Washington, D.C. U.S. Government Printing Office, 1997. 211]**QC REVIEWED**

Wear appropriate eye protection to prevent eye contact.
[NIOSH. NIOSH Pocket Guide to Chemical Hazards. DHHS (NIOSH) Publication No. 97-140. Washington, D.C. U.S. Government Printing Office, 1997. 211]**QC REVIEWED**

Eyewash fountains should be provided in areas where there is any possibility that workers could be exposed to the substance; this is irrespective of the recommendation involving the wearing of eye protection.
[NIOSH. NIOSH Pocket Guide to Chemical Hazards. DHHS (NIOSH) Publication No. 97-140. Washington, D.C. U.S. Government Printing Office, 1997. 211]**QC REVIEWED**

Facilities for quickly drenching the body should be provided within the immediate work area for emergency use where there is a possibility of exposure. (Note: It is intended that these facilities provide a sufficient quantity or flow of water to quickly remove the substance from any body areas likely to be exposed. The actual determination of what constitutes an adequate quick drench facility depends on the specific circumstances. In certain instances, a deluge shower should be readily available, whereas in others, the availability of water from a sink or hose could be considered adequate.)
[NIOSH. NIOSH Pocket Guide to Chemical Hazards. DHHS (NIOSH) Publication No. 97-140. Washington, D.C. U.S. Government Printing Office, 1997. 211]**QC REVIEWED**

Recommendations for respirator selection. Condition: At concentrations above the NIOSH REL, or where there is no REL, at any detectable concentration. Respirator Class(es): Any self-contained breathing apparatus that has a full facepiece and is operated in a pressure-demand or other positive-pressure mode. Any supplied-air respirator that has a full facepiece and is operated in a pressure-demand or other positive-pressure mode in combination with an auxiliary self-contained breathing apparatus operated in pressure-demand or other positive-pressure mode.
[NIOSH. NIOSH Pocket Guide to Chemical Hazards. DHHS (NIOSH) Publication No. 97-140. Washington, D.C. U.S. Government Printing Office, 1997. 211]**QC REVIEWED**

Recommendations for respirator selection. Condition: Escape from suddenly occurring respiratory hazards: Respirator Class(es): Any appropriate escape-type, self-contained breathing apparatus.
[NIOSH. NIOSH Pocket Guide to Chemical Hazards. DHHS (NIOSH) Publication No. 97-140. Washington, D.C. U.S. Government Printing Office, 1997. 211]**QC REVIEWED**

Preventive Measures:

Contact lenses should not be worn when working with this chemical.
[NIOSH. NIOSH Pocket Guide to Chemical Hazards. DHHS (NIOSH) Publication No. 97-140. Washington, D.C. U.S. Government Printing Office, 1997. 211]**QC REVIEWED**

SRP: The scientific literature for the use of contact lenses in industry is conflicting. The benefit or detrimental effects of wearing contact lenses depend not only upon the substance, but also on factors including the form of the substance, characteristics and duration of the exposure, the uses of other eye protection equipment, and the hygiene of the lenses. However, there may be individual substances whose irritating or corrosive properties are such that the wearing of contact lenses would be harmful to the eye. In those specific cases, contact lenses should not be worn. In any event, the usual eye protection equipment should be worn even when contact lenses are in place.
**PEER REVIEWED**

Evacuation: If fire becomes uncontrollable or container is exposed to direct flame consider evacuation of one (1/3) mile radius.
[Association of American Railroads. Emergency Handling of Hazardous Materials in Surface Transportation. Washington, DC: Association of American Railroads, Bureau of Explosives, 1994. 730]**PEER REVIEWED**

Personnel protection: Avoid breathing vapors. Keep upwind. ... Avoid bodily contact with the material. ... Do not handle broken packages unless wearing appropriate personal protective equipment. Wash away any material which may have contacted the body with copious amounts of water or soap and water.
[Association of American Railroads. Emergency Handling of Hazardous Materials in Surface Transportation. Washington, DC: Association of American Railroads, Bureau of Explosives, 1994. 730]**PEER REVIEWED**

SRP: Contaminated protective clothing should be segregated in such a manner so that there is no direct personal contact by personnel who handle, dispose, or clean the clothing. Quality assurance to ascertain the completeness of the cleaning procedures should be implemented before the decontaminated protective clothing is returned for reuse by the workers. Contaminated clothing should not be taken home at end of shift, but should remain at employee's place of work for cleaning.
**PEER REVIEWED**

Inhalation of salt dusts should be avoided. /Hydrazine & derivatives/
[Kirk-Othmer Encyclopedia of Chemical Technology. 3rd ed., Volumes 1-26. New York, NY: John Wiley and Sons, 1978-1984.,p. V12 758 (1980)]**PEER REVIEWED**

Engineering controls, such as process enclosure or local exhaust ventilation, shall be used when needed to keep concentrations of airborne hydrazines within acceptable levels. Ventilation systems shall be designed to prevent accumulation or recirculation of airborne hydrazines in the workplace environment and to remove hydrazines from the breathing zone of workers. /Hydrazines/
[NIOSH; Criteria Document: Hydrazine p.10 (1978) DHEW Pub. NIOSH 78-172]**PEER REVIEWED**

If material not on fire and not involved in fire: Keep sparks, flames, and other sources of ignition away. Keep material out of water sources and sewers. Build dikes to contain flow as necessary. Attempt to stop leak if without undue personnel hazard. Use water spray to diperse vapors and dilute standing pools of liquid.
[Association of American Railroads. Emergency Handling of Hazardous Materials in Surface Transportation. Washington, DC: Association of American Railroads, Bureau of Explosives, 1994. 730]**PEER REVIEWED**

The worker should immediately wash the skin when it becomes contaminated.
[NIOSH. NIOSH Pocket Guide to Chemical Hazards. DHHS (NIOSH) Publication No. 97-140. Washington, D.C. U.S. Government Printing Office, 1997. 211]**QC REVIEWED**

Work clothing that becomes wet should be immediately removed due to its flammability hazard.
[NIOSH. NIOSH Pocket Guide to Chemical Hazards. DHHS (NIOSH) Publication No. 97-140. Washington, D.C. U.S. Government Printing Office, 1997. 211]**QC REVIEWED**

Shipment Methods and Regulations:

No person may /transport,/ offer or accept a hazardous material for transportation in commerce unless that person is registered in conformance ... and the hazardous material is properly classed, described, packaged, marked, labeled, and in condition for shipment as required or authorized by ... /the hazardous materials regulations (49 CFR 171-177)./
[49 CFR 171.2 (7/1/96)]**PEER REVIEWED**

The International Air Transport Association (IATA) Dangerous Goods Regulations are published by the IATA Dangerous Goods Board pursuant to IATA Resolutions 618 and 619 and constitute a manual of industry carrier regulations to be followed by all IATA Member airlines when transporting hazardous materials.
[IATA. Dangerous Goods Regulations. 38th ed. Montreal, Canada and Geneva, Switzerland: International Air Transport Association, Dangerous Goods Board, January, 1997. 179]**PEER REVIEWED**

The International Maritime Dangerous Goods Code lays down basic principles for transporting hazardous chemicals. Detailed recommendations for individual substances and a number of recommendations for good practice are included in the classes dealing with such substances. A general index of technical names has also been compiled. This index should always be consulted when attempting to locate the appropriate procedures to be used when shipping any substance or article.
[IMDG; International Maritime Dangerous Goods Code; International Maritime Organization p.3091 (1988)]**PEER REVIEWED**

Storage Conditions:

Store in a cool, dry, well-ventilated location. Separate from acids, oxidizing materials, halogens, & air. Outside or detached storage is preferred.
[Fire Protection Guide to Hazardous Materials. 12 ed. Quincy, MA: National Fire Protection Association, 1997.,p. 49-89]**QC REVIEWED**

Cleanup Methods:

Wear butyl rubber gloves, self-contained breathing apparatus, eye protection and impervious clothing. Body shield should be available. Eliminate all sources of ignition and flammables. On skin or clothing. Wash skin immediately. Remove contaminated clothing at once. Spills: Cover spill with a 1:1:1 mixture by weight of sodium carbonate or calcium carbonate, clay cat litter (bentonite) and sand. Scoop the solid into a container, transport to the fume hood and slowly add to water allowing 20 ml water for each 1 g of methylhydrazine. Filter off the clay and sand. For each 1 g of methylhydrazine, place 41 ml (about 25% excess) of commercial laundry bleach (containing about 5.25% sodium hypochlorite) into a 3-necked round-bottom flask equipped with a stirrer, thermometer and dropping funnel. Add the aqueous methylhydrazine dropwise to the stirred hypochlorite solution, monitoring the rate of addition by rise in temperature. The temperature is maintained at 45-50 deg C and addition takes about 1 hour. Stirring is continued for 2 hours until the temperature gradually falls to room temperature.
[Armour, M.A. Hazardous Laboratory Chemicals Disposal Guide. Boca Raton, FL: CRC Press Inc., 1991. 230]**PEER REVIEWED**

Disposal Methods:

Generators of waste (equal to or greater than 100 kg/mo) containing this contaminant, EPA hazardous waste number P068, must conform with USEPA regulations in storage, transportation, treatment and disposal of waste.
[40 CFR 240-280, 300-306, 702-799 (7/1/92)]**PEER REVIEWED**

Methyl hydrazine is a good candidate for liquid injection incineration with a temperature range of 650 to 1600 deg C and a residence time of 0.1 to 2 seconds. Also a good candidate for rotary kiln incineration with a temperature range of 820 to 1,600 deg C and residence times of seconds for liquids and gases; for solids hours. Also a good candidate fluidized bed incineration with a temperature range of 450 to 980 deg C and residence times of seconds for liquids and gases; longer for solids.
[USEPA; Engineering Handbook for Hazardous Waste Incineration p.3-9 (1981) EPA 68-03-3025]**PEER REVIEWED**

Small Quantities. Wear butyl rubber gloves, laboratory coat and eye prolection. Work in the fume hood. Prepare a dilute (5%) aqueous solution of methylhydrazine by adding slowly to the appropriate volume of water. For each 1 g of methylhydrazine, place 41 ml (about 25% excess) of household laundry bleach (5.25% sodium hypochlorite) into a 3-necked round-bottom flask equipped with a stirrer, thermometer and dropping funnel. Add the aqueous methylhydrazi