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HYDROGEN SULFIDE
CASRN: 7783-06-4

See Occupational Exposure Standards

 

Human Health Effects:

Evidence for Carcinogenicity:

There are no published reports of carcinogenesis, mutagenesis, or teratogenesis attributable to hydrogen sulfide exposure.
[Sullivan, J.B. Jr., G.R. Krieger (eds.). Hazardous Materials Toxicology-Clinical Principles of Environmental Health. Baltimore, MD: Williams and Wilkins, 1992. 714]**PEER REVIEWED**

Human Toxicity Excerpts:

SYMPTOMATOLOGY: A. LOW TO MODERATELY HIGH VAPOR CONCENTRATIONS: 1. IRRITANT ACTIONS. EYES: PAINFUL CONJUNCTIVITIS, PHOTOPHOBIA, LACRIMATION, & CORNEAL OPACITY. RESP TRACT: RHINITIS WITH ANOSMIA, TRACHEOBRONCHITIS WITH PAIN AND COUGH, PULMONARY EDEMA WITH DYSPNEA, SOMETIMES LATE BRONCHOPNEUMONIA. SKIN: DIRECT CONTACT (AS SOLN) MAY PRODUCE ERYTHEMA & PAIN. B. VERY HIGH VAPOR CONCENTRATIONS: 1. SUDDEN COLLAPSE & UNCONSCIOUSNESS, WITH OR WITHOUT A WARNING CRY. 2. DEATH FROM PROMPT RESP PARALYSIS, USUALLY WITH TERMINAL ASPHYXIAL CONVULSION. 3. AFTER SUBLETHAL EXPOSURES COMA MAY DISAPPEAR PROMPTLY, BUT FULL RECOVERY IS USUALLY SLOW; THE PATIENT MAY HAVE A RESIDUAL COUGH, CARDIAC DILATATION, SLOW PULSE, PERIPHERAL ... /NEUROPATHY/, ALBUMINURIA AND SOME DEGREE OF AMNESIA OR OF PSYCHIC DISTURBANCE. RECOVERY IS EVENTUALLY COMPLETE IN MOST NONFATAL CASES.
[Gosselin, R.E., R.P. Smith, H.C. Hodge. Clinical Toxicology of Commercial Products. 5th ed. Baltimore: Williams and Wilkins, 1984.,p. III-200]**PEER REVIEWED**

A CASE OF POLYNEURITIS AND ENCEPHALOPATHY FROM 1 DAY EXPOSURE TO A CONCN INSUFFICIENT TO CAUSE LOSS OF CONSCIOUSNESS HAS BEEN REPORTED.
[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. 318]**PEER REVIEWED**

ANALYSIS OF RETICULOCYTES FOR DELTA-AMINO-LEVULINIC ACID SYNTHASE (AMLEV SYNTHASE) AND HEME SYNTHASE ACTIVITY IN WORKERS IN PULP PRODUCTION WITH LOW-LEVEL HYDROGEN SULFIDE AND METHYLMERCAPTAN EXPOSURE SHOWED DECREASED ACTIVITIES. ERYTHROCYTE PROTOPORPHYRIN CONCENTRATION WAS BELOW THE CONTROL RANGE IN 7 CASES. LOW AMLEV SYNTHASE AND HEME SYNTHASE ACTIVITIES WERE FOUND IN 1 PATIENT WITH HYDROGEN SULFIDE INTOXICATION 1 WEEK AFTER THE EVENT. THE ACTIVITIES HAD RETURNED TO THE CONTROL LEVELS 2 MONTHS LATER, THOUGH ERYTHROCYTE PROTOPORPHYRIN REMAINED ABNORMALLY LOW. IN VITRO, HYDROGEN SULFIDE INHIBITED HEME SYNTHASE WITH AN APPARENT KI OF 3.4 MMOL/L. SULFIDE ANION INHIBITED AMLEV SYNTHASE ACTIVITY 85% AT 10 MMOL/L.
[TENHUNEN P ET AL; CLIN SCI 64 (2): 187-91 (1983)]**PEER REVIEWED**

SPONTANEOUS ABORTIONS WERE ANALYZED IN AN INDUSTRIAL COMMUNITY IN FINLAND IN WOMEN WHO WERE EMPLOYED IN RAYON TEXTILE JOBS AND PAPER PRODUCTS JOBS. AN INCREASED RATE OF SPONTANEOUS ABORTIONS WAS NOTED IN ALL SOCIOECONOMIC CLASSES IN AREAS WHERE THE MEAN ANNUAL LEVEL OF HYDROGEN SULFIDE EXCEEDED 4 UG/CU M. HOWEVER, THE DIFFERENCE (TOTAL RATES 7.6 AND 9.3, RESPECTIVELY) WAS NOT STATISTICALLY SIGNIFICANT.
[HEMMINKI K, NIEMI ML; INT ARCH OCCUP ENVIRON HEALTH 51 (1): 55-63 (1982)]**PEER REVIEWED**

HYDROGEN SULFIDE IS ASSOCIATED WITH DEATHS CAUSED BY FERMENTING MANURE.
[MORSE DL ET AL; JAMA 25 (1): 63-4 (1981)]**PEER REVIEWED**

HYDROGEN SULFIDE CAN PENETRATE SKIN & CAUSE TOXICOSIS IN PEOPLE EXPOSED TO LARGE CONCN OVER LONG PERIOD ... SPEED OF ONSET OF ACUTE HYDROGEN SULFIDE POISONING & POTENCY OF HYDROGEN SULFIDE ARE ALMOST SAME AS FOR CYANIDE GAS ...
[Jones, L.M., et al. Veterinary Pharmacology & Therapeutics. 4th ed. Ames: Iowa State University Press, 1977. 1161]**PEER REVIEWED**

Low concentrations of 20-150 ppm cause irritation of the eyes; slightly higher concentrations may cause irritation of the upper respiratory tract, and if exposure is prolonged, pulmonary edema may result. The irritant action has been explained on the basis that hydrogen sulfide combines with the alkali present in moist surface tissues to form sodium sulfide, a caustic.
[Lewis, R.J. Sax's Dangerous Properties of Industrial Materials. 9th ed. Volumes 1-3. New York, NY: Van Nostrand Reinhold, 1996. 1843]**PEER REVIEWED**

... OF 174 EXPOSURES TO HYDROGEN SULFIDE IN A HEAVY WATER PLANT ... EYE IRRITATION WAS RELATIVELY UNCOMMON. MORE COMMON FINDINGS WERE NERVOUSNESS, COUGH, NAUSEA, HEADACHE & INSOMNIA.
[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. 787]**PEER REVIEWED**

As concentrations approach 100 ppm,...odor becomes imperceptible because of olfactory fatigue. At these levels, the gas disrupts cellular respiration and may cause profound respiratory depression as well as cardiac dysrhythmias.
[Zenz, C., O.B. Dickerson, E.P. Horvath. Occupational Medicine. 3rd ed. St. Louis, MO., 1994 886]**PEER REVIEWED**

At a concentration of 150 ppm, the olfactory nerve is paralyzed.
[USEPA; Health and Environmental Effects Profile for Hydrogen Sulfide p.118-8 (1980) ECAO-CIN-026A]**PEER REVIEWED**

Hydrogen sulfide is an extremely hazardous gas which can be immediately life threatening at high concentrations (300 mg/cu m or 200 ppm).
[NIOSH: Occupational Exposure to Hydrogen Sulfide p.79 (1977) DHEW (NIOSH) Publication # 77-158]**PEER REVIEWED**

1400-2,800 mg/cu m inhalation <20 min number of subjects 342, hospitalization of 320, death of 22, residual nervous system damage in 4.
[McCabe LC, Clayton GD; Arch Ind Hyg Occup Med (6): 199-213 (1952) as cited in NIOSH: Occupational Exposure to Hydrogen Sulfide; p.61 (l977) DHEW (NIOSH) Publication # 77-l58]**PEER REVIEWED**

Concentrations of 20-50 ppm irritates the eyes. Inhalation of 500 ppm for 30 minutes produces headache, dizziness, excitement, staggering, and gastroenteric disorders followed in some cases by bronchitis or bronchial pneumonia. Concentrations above 600 ppm can be fatal within 30 minutes through respiratory paralyses.
[Matheson; Guide to Safe Handling of Compressed Gases 2nd ED p.15 (1983)]**PEER REVIEWED**

Prolonged exposure may cause pulmonary edema at 250 pp.
[Sullivan, J.B. Jr., G.R. Krieger (eds.). Hazardous Materials Toxicology-Clinical Principles of Environmental Health. Baltimore, MD: Williams and Wilkins, 1992. 712]**PEER REVIEWED**

AT HIGH CONCN HYDROGEN SULFIDE PRODUCES PARALYSIS OF OLFACTORY NERVES (ANOSMIA) & ODOR DETECTION IS INEFFECTIVE AS A WARNING FOR HYDROGEN SULFIDE.
**PEER REVIEWED**

A group of 9 men and 10 women inhaled medical air or 10 ppm hydrogen sulfide for 15 min during cycle exercise at 50% of their maximal aerobic power. Routine pulmonary function tests were administered at rest and immediately after the two exposure conditions. No significant changes in pulmonary function variables were /noted/ and none of the subjects experienced any signs or symptoms as a result of hydrogen sulfide exposure. Oral inhalation of 10 ppm hydrogen sulfide at an elevated metabolic and ventilation rate does not significantly alter pulmonary function in healthy men and women.
[Bhambhani Y, et al; J Occupat Environ Med 38 (10): 1012-17 (1996)]**PEER REVIEWED**

In the 19th century, deaths from acute exposure to hydrogen sulfide portended permanent brain injury from non-lethal /exposures/. The neurobehavioral effects of H2S exposures lasting from moments to years were compared in 16 healthy subjects, 2 yr to 22 yr afterward. Neurophysiologic and psychologic tests were used to appraise mood status and frequencies of 35 symptoms. Functions and frequencies, described as percent predicted adjusted for age, sex, educational achievement, and other factors, were compared with those in an unexposed population. ... Frequencies were elevated for 31 of 33 symptoms. Balance was impaired (246% predicted with eyes closed, 159% predicted with eyes open), and simple and choice reaction times were prolonged (151% and 130% predicted, respectively). Visual fields performance was decr to 72% predicted (right) and 55% predicted (left), color discrimination was abnormal, and hearing was decr.Psychologic domains showed cognitive disability, reduced perceptual motor speed, impaired verbal recall and remote memory, and abnormal mood status. ...
[Kilburn KH; South Med J 90 (10): 997-1006 (1997)]**PEER REVIEWED**

Respiratory symptoms and lung function in relation to hydrogen sulfide exposure was assessed in oil and natural gas workers in Alberta, Canada. 175 workers were questioned about gas exposures strong enough to cause respiratory symptoms and those that caused loss of consciousness (knockdowns); assessments included spirometry and skin prick testing. Exposures strong enough to cause symptoms were reported by 34% of the workers. These exposures were not associated with lower spirometric values or incr prevalence of symptoms. Exposures strong enough to cause unconsciousness were reported by 8% of the workers. while these knockdowns were not associated with lower spirometric values, they were associated with excesses of shortness of breath while hurrying, wheeze with chest tightness, and attacks of wheeze. Respiratory symptoms were consistent with bronchial hyperactivity. ...
[Hessel PA, et al; Amer J Indust Med 31 (5): 554-7 (1997)]**PEER REVIEWED**

The acute effects of hydrogen sulfide (H2S) on the cardiovascular, metabolic and biochemical responses of exercising men and women were /evaluated/. The maximal aerobic power (VO2max) of 15 male and 13 female subjects was determined during the first exercise session. During two subsequent exercise sessions, the subjects inhaled either medical air or an H2S dose of 10 ppm while performing at 50% of their VO2max. A number of physiological parameters were monitored, including blood pressure and expiratory gasses. Muscle biopsies, blood analyses, and tissue analyses were performed. Muscle lactate, lactate dehydrogenase (LDH), citrate synthase (CS) and cytochrome oxidase quantities were analyzed. H2S inhalation had no significant effect on partial pressures of oxygen or carbon dioxide, hemoglobin saturation, or arterial blood pH. H2S inhalation significantly reduced the VO2 and significantly incr the delta blood in both men and women. Neither heart rate nor blood pressure was affected by H2S inhalation. Muscle lactate incr, although not significantly in men and women exposed to H2S. The LDH and CS activities decr by about 7% each after H2S inhalation. Following H2S inhalation, cytochrome oxidase activity decr by 16% in men and incr by 11% in women. ...
[Bhambhani Y, et al; J Occupat Environ Med 39 (2): 122-9 (1997)]**PEER REVIEWED**

Human Toxicity Values:

Man: severe toxic effects 200 ppm = 280 mg/cu m 1 min; symptoms of illness 50 ppm = 70 mg/cu m; unsatisfactory: 20 ppm = 28 mg/cu m
[Verschueren, K. Handbook of Environmental Data of Organic Chemicals. 2nd ed. New York, NY: Van Nostrand Reinhold Co., 1983. 745]**PEER REVIEWED**

Man: lethal: 600 ppm/30 min; 800 ppm, immediate /lethality/
[Verschueren, K. Handbook of Environmental Data of Organic Chemicals. 2nd ed. New York, NY: Van Nostrand Reinhold Co., 1983. 745]**PEER REVIEWED**

Lethal blood concentration: 0.092 mg %.
[Winek, C.L. Drug and Chemical Blood-Level Data 1985. Pittsburgh, PA: Allied Fischer Scientific, 1985.]**PEER REVIEWED**

Skin, Eye and Respiratory Irritations:

The direct action of H2S on mucous membranes is usually observed first by symptoms of eye irritation, resulting from local inflammation of the conjunctiva and cornea. Acute inflammation of conjunctiva accompanied by lacrimation and mucopurulent exudate is not uncommon. In severe cases, corneal erosion with blurred vision may also occur. Occasionally, corneal ulceration may occur, resulting in impaired vision. Since the cornea is affected together with the conjunctiva in many instances, keratoconjunctivitis rather than conjunctivitis more accurately describes the ophthalmologic effects of H2S exposure. In general, irritation of the eyes occurs at a concentration of H2S of 50 ppm; however, conjunctivitis or "sore eyes" have been observed upon exposures in the range of 5-100 ppm.
[Sullivan, J.B. Jr., G.R. Krieger (eds.). Hazardous Materials Toxicology-Clinical Principles of Environmental Health. Baltimore, MD: Williams and Wilkins, 1992. 713]**PEER REVIEWED**

Eye and respiratory tract irritation is noticeable at 50 ppm. ...
[Sullivan, J.B. Jr., G.R. Krieger (eds.). Hazardous Materials Toxicology-Clinical Principles of Environmental Health. Baltimore, MD: Williams and Wilkins, 1992. 712]**PEER REVIEWED**

Irritant to eyes and mucuous membranes ...
[Lewis, R.J. Sax's Dangerous Properties of Industrial Materials. 9th ed. Volumes 1-3. New York, NY: Van Nostrand Reinhold, 1996. 1843]**PEER REVIEWED**

The irritant effect of H2S extends rather uniformly throughout the entire respiratory tract, resulting in rhinitis, pharyngitis, laryngitis, bronchitis, and pneumonia. Cough, sore throat, hoarseness, runny nose, and chest tightness are the most common symptoms of exposure between 50 and 250 ppm.
[Sullivan, J.B. Jr., G.R. Krieger (eds.). Hazardous Materials Toxicology-Clinical Principles of Environmental Health. Baltimore, MD: Williams and Wilkins, 1992. 713]**PEER REVIEWED**

Medical Surveillance:

Placement medical examinations should evaluate any existing neurological, eye and respiratory conditions and any history of fainting seizures. It is recommended by NIOSH that placement and periodic examinations (once every 3 years) be made available to all workers occupationally exposed to hydrogen sulfide.
[Sittig, M. Handbook of Toxic and Hazardous Chemicals and Carcinogens, 1985. 2nd ed. Park Ridge, NJ: Noyes Data Corporation, 1985. 513]**PEER REVIEWED**

Probable Routes of Human Exposure:

Inhalation of gas, ingestion, eye, and skin contact.
[Sittig, M. Handbook of Toxic and Hazardous Chemicals and Carcinogens, 1985. 2nd ed. Park Ridge, NJ: Noyes Data Corporation, 1985. 513]**PEER REVIEWED**

MAJORITY OF OCCUPATIONAL EXPOSURES TO HYDROGEN SULFIDE RESULTED FROM ITS OCCURRENCE IN PETROLEUM, NATURAL GAS, SOIL, SEWER GAS & AS BYPRODUCT OF CHEM REACTIONS, SUCH AS MAY TAKE PLACE IN VISCOSE RAYON & CERTAIN LEATHER TANNING PROCESSES.
[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. 786]**PEER REVIEWED**

... /GAS/ RELEASED FROM SLURRY TANKS IN PIGGERIES WHEN THE SLURRY HAS AGITATED PRIOR TO PUMPING. UNDER THESE CONDITIONS GAS CAN BUILD UP TO TOXIC LEVEL (80-800 PPM); ON OCCASIONS MEN WORKING ON SITE HAVE BEEN OVERCOME.
[Humphreys, D.J. Veterinary Toxicology. 3rd ed. London, England: Bailliere Tindell, 1988. 83]**PEER REVIEWED**

LIQUID MANURE STORAGE IS A COMMON COMPONENT OF CONFINEMENT SYSTEMS FOR SWINE, BEEF, DAIRY, AND VEAL OPERATIONS. MORE THAN 85,000 PEOPLE IN IOWA AND 500,000 IN THE REST OF THE THE US WORK IN LIVESTOCK CONFINEMENT SYSTEMS THAT USE LIQUID MANURE STORAGE. ... TOXIC GASES EMANATING FROM THE LIQUID MANURE /MAY INCLUDE HYDROGEN SULFIDE/
[DONHAM KJ ET AL; J OCCUP MED 24 (2): 142-5 (1982)]**PEER REVIEWED**

GAS EXPOSURE RISK FROM COAL GASIFICATION PRODUCTS AT THE UCG PROJECT, RAWLINS, WYOMING IS DISCUSSED.
[MOORE J ET AL; PROC INT GAS RES CONF, 2ND: 1645-50 (1982)]**PEER REVIEWED**

Emergency Medical Treatment:

Emergency Medical Treatment:

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The following Overview, *** HYDROGEN SULFIDE ***, 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   Hydrogen sulfide is a highly toxic, flammable,
         colorless gas produced by decaying organic matter and
         has a characteristic odor of rotten eggs at low
         concentrations however, the sense of smell is paralyzed
         at airborne levels above 50 to 150 ppm.
      1.  Exposure to concentrations of near 250 ppm causes
          irritation of mucous membranes, conjunctivitis,
          photophobia, lacrimation, corneal opacity, rhinitis,
          bronchitis, cyanosis, and acute lung injury.
      2.  At concentrations of 250 to 500 ppm, signs and
          symptoms include headache, nausea, vomiting, diarrhea,
          vertigo, amnesia, dizziness, apnea, palpitations,
          tachycardia, hypotension, muscle cramps, weakness,
          disorientation, and coma.
      3.  At concentrations of 750 to 1000 ppm, victims may
          experience abrupt physical collapse or "knock down".
          Higher concentrations may also result in result in
          respiratory paralysis, asphyxial seizures, and death.
          The mortality rate is in the range of 6 percent.
       a.  Characteristics of a fatal exposure are rapid "knock
           down," respiratory depression, tremors, blurred
           vision, cyanosis, seizures and tachycardia.
  VITAL SIGNS
   0.2.3.1 ACUTE EXPOSURE
     o   Patients may acutely present with bradycardia,
         tachycardia, hyperventilation, respiratory depression
         even to the point of apnea, and/or hypo-/hypertension.
  HEENT
   0.2.4.1 ACUTE EXPOSURE
     o   Injection of the conjunctivae, seeing colored halos,
         ocular pain, corneal bullae, blurred vision and
         blepharospasm may be noted following exposure to 150 to
         300 ppm.
   0.2.4.2 CHRONIC EXPOSURE
     o   Rhinitis may be seen with chronic exposure.
  CARDIOVASCULAR
   0.2.5.1 ACUTE EXPOSURE
     o   Tachycardia, bradycardia, cardiac dysrhythmias, and
         either hyper or hypotension may be seen.
  RESPIRATORY
   0.2.6.1 ACUTE EXPOSURE
     o   Respiratory depression, cyanosis, pulmonary edema,
         bronchitis, and dyspnea may be noted following exposure
         to non-fatal concentrations.
     o   Exposure to high concentrations will result in rapid
         respiratory paralysis leading to sudden collapse.
  NEUROLOGIC
   0.2.7.1 ACUTE EXPOSURE
     o   Asphyxial seizures, coma, and death associated with
         rapid respiratory paralysis may be noted following
         exposure to high concentrations.
     o   Headache, sweating, vertigo, anosmia, irritability,
         staggering gait, disorientation, somnolence, weakness,
         confusion, and delirium may be noted following exposure
         to non-fatal levels.
  GASTROINTESTINAL
   0.2.8.1 ACUTE EXPOSURE
     o   Nausea and vomiting may be noted.  Weight loss can be
         seen with chronic exposure.
  GENITOURINARY
   0.2.10.1 ACUTE EXPOSURE
     o   Exposure may rarely cause albuminuria, cylindruria, and
         hematuria.
  ACID-BASE
   0.2.11.1 ACUTE EXPOSURE
     o   Transient lactic acidosis may be noted following
         significant exposure.
  DERMATOLOGIC
   0.2.14.1 ACUTE EXPOSURE
     o   Skin exposure may result in severe pain, itching, and
         erythema, especially in moist areas.  Cyanosis may be
         noted following severe exposure.
  REPRODUCTIVE HAZARDS
    o   Spontaneous abortions have occurred after exposure to
        life-threatening concentrations.
  CARCINOGENICITY
   0.2.21.2 HUMAN OVERVIEW
     o   In Rotorua, New Zealand (an active geothermal zone
         where hydrogen sulfide is released to the atmosphere),
         cancer deaths were not related to the extent of
         hydrogen sulfide exposure and there was no overall
         excess mortality found.
  GENOTOXICITY
    o   Hydrogen sulfide exposure was associated with an
        increased risk of chromosome aberrations in chemical
        workers.  Other factors may be involved in these
        multiply-exposed cohort populations.
Laboratory:
  o   Monitor vital signs.  Monitor pulse oximetry and/or
      arterial blood  gases and chest radiograph in patients
      with respiratory signs or symptoms.
  o   Measuring blood sulfide or thiosulfate levels may be done
      to document the exposure but are not useful for emergent
      diagnosis or to guide emergency treatment.
  o   Monitor methemoglobin levels if nitrite antidotes are
      administered.                             
Treatment Overview:
  SUMMARY EXPOSURE
    o   Move the victim to an area of fresh air and immediately
        provide respiratory support using 100 percent humidified
        oxygen.
    o   Although its efficacy is still unproven, nitrite therapy
        is recommended if it can be started early.
    o   Hyperbaric oxygen may be given to those who continue to
        be symptomatic after standard therapy.
    o   Measures should be taken to control seizures, pulmonary
        edema, and arrhythmias and to correct hypotension.
    o   Exposed mucocutaneous surfaces should be thoroughly
        washed with copious amounts of water and/or soap.
    o   Rescuers should wear a self-contained breathing
        apparatus, special chemical protective clothing, and a
        safety line during rescue operations.  Many would-be
        rescuers have become victims when entering contaminated
        enclosed areas without proper protective equipment.
    o   Observe for delayed onset (up to 72 hours) acute
        respiratory effects.
  ORAL EXPOSURE
    o   Hydrogen sulfide is a gas at room temperature (Harbison,
        1998), making ingestion unlikely.
  INHALATION EXPOSURE
    o   IMMEDIATELY MOVE PATIENT TO FRESH AIR AND ADMINISTER 100
        PERCENT OXYGEN.  PREVENT SELF-EXPOSURE and possible
        death by wearing a self-contained breathing apparatus to
        rescue the victim.
    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   HYPOTENSION:  Infuse 10 to 20 mL/kg isotonic fluid,
        place in Trendelenburg position.  If hypotension
        persists, administer dopamine (5 to 20 mcg/kg/min) or
        norepinephrine (0.1 to 0.2 mcg/kg/min), titrate to
        desired response.
    o   NITRITE THERAPY - Amyl nitrite by inhalation and IV
        sodium nitrite (found in cyanide antidote kit) may be
        beneficial by forming sulfmethemoglobin, thus removing
        sulfide from combination in tissue.  Do NOT use sodium
        thiosulfate.  The antidotal efficacy of nitrite therapy
        is controversial; it should be  considered in patients
        with severe symptoms who present soon after exposure.
    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.
  DERMAL EXPOSURE
    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.     
Range of Toxicity:
  o   At an airborne concentration of 0.05 ppm, hydrogen sulfide
      produces a characteristic rotten eggs odor.  At 50 to 150
      ppm the sense of smell is paralyzed after a short time and
      gradually worsening symptoms are noted.
  o   Exposure to greater than 500 ppm results in severe
      toxicity and death.  Respiratory paralysis and death may
      be noted within 30 to 60 minutes.  At 800 to 1000 ppm,
      death may be nearly immediate after 1 or more breaths.

[Rumack BH: POISINDEX(R) Information System. Micromedex, Inc., Englewood, CO, 2003; CCIS Volume 116, edition exp May, 2003. Hall AH & Rumack BH (Eds):TOMES(R) Information System. Micromedex, Inc., Englewood, CO, 2003; CCIS Volume 116, edition exp May, 2003.] **PEER REVIEWED**

Antidote and Emergency Treatment:

NITRITE AS AN ANTIDOTE FOR ACUTE HYDROGEN SULFIDE INTOXICATION CAN ONLY BE EFFECTIVE WITHIN THE FIRST FEW MINUTES AFTER THE EXPOSURE, AT WHICH TIME RESUSCITATION AND/OR VENTILATION OF THE VICTIM ARE LIKELY TO PRODUCE CONDITIONS IN WHICH THE NITRITE ACTUALLY SLOWS SULFIDE REMOVAL /SRP: DUE TO DECR BINDING OF THE SULFIDE TO METHEMOGLOBIN/.
[BECK JF ET AL; AM J IND HYG ASSOC J 42 (11): 805-9 (1981)]**PEER REVIEWED**

Immediately remove person from exposure and ensure that the airway is clear. Given 100% oxygen by tight-fitting oronasal mask or endotracheal tube. Hyperbaric oxygen at 3 atm has been successful.
[Zenz, C., O.B. Dickerson, E.P. Horvath. Occupational Medicine. 3rd ed. St. Louis, MO., 1994 667]**PEER REVIEWED**

A CASE REPORT OF A 34-YEAR-OLD MALE RENDERED UNCONSCIOUS BY EXPOSURE TO A HIGH CONCENTRATION OF HYDROGEN SULFIDE FUMES IS PRESENTED TO ILLUSTRATE THE ADVANTAGES OF OXYGEN THERAPY. SIGNIFICANT IMPROVEMENT IN BLOOD GASES WAS ACHIEVED WITHIN 1 HOUR OF STARTING OXYGEN. THE RISKS OF NITRITE THERAPY ARE DISCUSSED.
[RAVIZZA G ET AL; VET HUM TOXICOL 24 (AUG): 241-2 (1982)]**PEER REVIEWED**

For basic treatment: Establish a patent airway. Suction if necessary. Watch for signs of respiratory insufficiency and assist ventilations if necessary. Administer oxygen by nonrebreather mask at 10 to 15 L/min. Monitor for pulmonary edema and treat if necessary ... . Monitor for shock and treat if necessary ... . Anticipate seizures and treat if necessary ... . For eye contamination, flush eyes immediately with water. Irrigate each eye continuously with normal saline during transport ... . Treat with rapid rewarming techniques ... if frostbite occurs. /Hydrogen sulfide and related compounds/
[Bronstein, A.C., P.L. Currance; Emergency Care for Hazardous Materials Exposure. 2nd ed. St. Louis, MO. Mosby Lifeline. 1994.,p. 391-2]**PEER REVIEWED**

For advanced treatment: Consider orotracheal or nasotracheal intubation for airway control in the patient who is unconscious or in respiratory arrest. Positive-pressure ventilation techniques with a bag-valve-mask device may be beneficial. Monitor cardiac rhythm and treat arrhythmias if necessary ... . Start an IV with D5W TKO /SRP: To keep open, "minimal flow rate"/. Use lactated Ringer's if signs of hypovolemia are present. Watch for signs of fluid overload. Consider drug therapy for pulmonary edema ... . For hypotension with signs of hypovolemia, administer fluid cautiously. Watch for signs of pulmonary edema. Consider vasopressors to treat hypotension without signs of hypovolemia ... . Treat seizures with diazepam (Valium) ... . In severe cases use amyl nitrite and sodium nitrite ... as described for cyanide poisoning; omit the sodium thiosulfate injection. Early administration will be the most effective. DIRECT PHYSICIAN ORDER ONLY ... . Use proparacaine hydrochloride to assist eye irrigation ... . /Hydrogen sulfide and related compounds/
[Bronstein, A.C., P.L. Currance; Emergency Care for Hazardous Materials Exposure. 2nd ed. St. Louis, MO. Mosby Lifeline. 1994. 392]**PEER REVIEWED**

In two separate incidents, 6 patients were poisoned with hydrogen sulfide (H2S) in sewer gas. In the first incident, mixing acid and sodium hydroxide based drain cleaners in a confined space resulted in 4 poisonings and 2 deaths. Three ... rescuers were seriously poisoned and 1 died. Two survivors had neurological sequelae. Sodium nitrite appeared to have some clinical efficacy in 1 case. The second incident involved 2 patients working on a pump in a sewage pond. A patient lying on a raft close to the pond was seriously poisoned; sodium nitrite was clinically efficacious and this patient survived without developing neurological sequelae. Sodium nitrate /needs/ further clinical study as a potential H2S antidote.
[Halll AH, Rumack BH; Vet Hum Toxicol 39 (3): 152-4 (1997)]**PEER REVIEWED**

A worker in a chemical synthetic factory had a presumed acute hydrogen sulfide intoxication and suffered from repetitive generalized tonic convulsions, cyanosis, shock and respiratory arrest. Dramatic response was obtained with amyl nitrate inhalation followed by intravenous administration of sodium nitrate and sodium thiosulfate. The rapid recovery without medical and neurological sequelae supports the efficacy of nitrite treatment in acute hydrogen sulfide intoxication.
[Huang CC, Chu NS; J Formosan Med Assoc 86 (9): 1018-20 (1987)]**PEER REVIEWED**

Animal Toxicity Studies:

Evidence for Carcinogenicity:

There are no published reports of carcinogenesis, mutagenesis, or teratogenesis attributable to hydrogen sulfide exposure.
[Sullivan, J.B. Jr., G.R. Krieger (eds.). Hazardous Materials Toxicology-Clinical Principles of Environmental Health. Baltimore, MD: Williams and Wilkins, 1992. 714]**PEER REVIEWED**

Non-Human Toxicity Excerpts:

IF EXPOSURE IS NOT TOO GREAT, COUGHING, LACRIMATION, MUCOUS NASAL DISCHARGE, DYSPNEA, DEPRESSION, FLUID SOUNDS IN LUNGS, & TERMINAL CYANOSIS & POSSIBLE CONVULSIONS MAY OCCUR. LARGE CONCN OF HYDROGEN SULFIDE MAY CAUSE SUDDEN COLLAPSE, CYANOSIS, DYSPNEA, ANOXIC CONVULSIONS, & RAPID DEATH. THERE MAY BE PULMONARY EDEMA & EDEMA OF INTESTINES & BRAIN. BLOOD IS DARK & FAILS TO CLOT. HEMORRHAGES MAY OCCUR IN VARIOUS ORGANS. LIVER & KIDNEY MAY MANIFEST DEGENERATIVE CHANGES.
[Booth, N.H., L.E. McDonald (eds.). Veterinary Pharmacology and Therapeutics. 5th ed. Ames, Iowa: Iowa State University Press, 1982. 9602]**PEER REVIEWED**

IN ANIMAL EXPT TEMPORARY DAMAGING EFFECT ... ON CORNEAL EPITHELIUM HAS ... BEEN DEMONSTRATED ON ... DOGS, CATS, RABBITS, & GUINEA PIGS ... USUALLY BY EXPOSURE TO 50 TO 100 PPM FOR SEVERAL HR OR DAYS.
[Grant, W.M. Toxicology of the Eye. 3rd ed. Springfield, IL: Charles C. Thomas Publisher, 1986. 496]**PEER REVIEWED**

THERE HAVE BEEN NUMEROUS RECORDS OF PIGS HAVING BEEN FATALLY POISONED BY HYDROGEN SULFIDE RELEASED /GAS/ FROM SLURRY TANKS IN PIGGERIES WHEN SLURRY HAS BEEN AGITATED PRIOR TO PUMPING. UNDER THESE CONDITIONS GAS CAN RAPIDLY BUILD UP TO A TOXIC LEVEL (80-800 PPM). CATTLE HAVE ALSO BEEN POISONED IN THIS WAY; CALVES SHOWED ATAXIA & ENTERITIS. ... ALTHOUGH SUDDEN EXPOSURE TO CONCN OF 0.04% MIGHT BE FATAL TO PIGS, THERE WERE NO PERMANENT ILL EFFECTS IN ANIMALS SURVIVING EXPOSURE TO 0.1% /OBSERVED/.
[Humphreys, D.J. Veterinary Toxicology. 3rd ed. London, England: Bailliere Tindell, 1988. 83]**PEER REVIEWED**

CASES POULTRY POISONING HAVE ... BEEN RECORDED. /AN/ EPISODE OCCURRED IN A BATTERY LAYING HOUSE; BIRDS AFFECTED WERE NEAREST /TO/ THE GROUND & TO A LEAKING MANHOLE COVER.
[Humphreys, D.J. Veterinary Toxicology. 3rd ed. London, England: Bailliere Tindell, 1988. 83]**PEER REVIEWED**

EXPOSURE OF CHANNEL CATFISH TO 0.5 MG/L HYDROGEN SULFIDE AT 20 DEG C RESULTED IN HYPERPNEA, FOLLOWED BY APNEA AND RESPIRATORY ARREST.
[TORRANS EL, CLEMENS HP; COMP BIOCHEM PHYSIOL C COMP PHARMACOL 71 (2): 183-190 (1982)]**PEER REVIEWED**

/Ten species of weeds 3 to 6 weeks of age were/ fumigated with 100 to 500 ppm hydrogen sulfide for four hours. /Results suggested that/ differences in susceptibility to injury /existed/ and ... that younger plants were more sensitive to damage than older ones. /Data also suggested/ that increases in temperature exacerbated the damage, as did dry soil.
[Benedict HM et al; National Air Pollution Symposium p. 177-90 (1955) as cited in USEPA; Health Assessment Document for Hydrogen Sulfide (Draft) p. 5-2 (1986)]**PEER REVIEWED**

In high concentrations (1000 to 3000 ppm) hydrogen sulfide was lethal to dogs. At 3000 ppm, respiration ceased after a few breaths; death occurred within 15 to 20 minutes at 1000 ppm.
[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. 786]**PEER REVIEWED**

...exposed monkeys at 500 ppm for durations of 22 to 35 min. Each of three monkeys lost consciousness abruptly in about 15 min.; microscopic examination revealed that the brain, particularly the motor cells of the cerebellum, was the principal target organ ...
[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. 786]**PEER REVIEWED**

POISONING WITH HYDROGEN SULFIDE ... HAS BEEN DESCRIBED FROM DRINKING CONTAMINATED WATER.
[Clarke, M. L., D. G. Harvey and D. J. Humphreys. Veterinary Toxicology. 2nd ed. London: Bailliere Tindall, 1981. 82]**PEER REVIEWED**

... The central nervous system (CNS) appears to be the major target organ /for hydrogen sulfide toxicity/. There is great potential for insult or injury to the developing or immature CNS. The risk of chronic or repeated exposures to low concn have not been well defined. Exposure to low concn of H2S to time pregnant rats from day 5 post coitus until day 21 postnatal results in architectural modification of cerebellar Purkinje cells, alteration of putative amino acid neurotransmitters and changes in monoamine levels in the developing rat brain up day 21 postnatal. H2S induced alterations in monoamine tissue levels observed in the developing rat brain return to control values if exposure is discontinued during development, that is, at day 21 postnatal.
[Roth SH, et al; Clin Exp Pharmacol Physiol 22 (5): 379-80 (1995)]**PEER REVIEWED**

Hydrogen sulfide (H2S) may produce deleterious effects on the developing central nervous system. The dendritic fields of developing Purkinje cells were analyzed to determine the effects of chronic exposure to low concn of H2S during perinatal development. Treatment with the two concn (20 and 50 ppm) of H2S produced severe alterations in the architecture and growth characteristics of the Purkinje cell dendritic fields. The ... modifications included longer branches, an incr in the vertex path length and variations in the number of branches in particular areas of the dendritic field.The treated cells ... exhibited a non-symmetrical growth pattern at a time when random terminal branching is normally occurring. ...
[Hannah RS, Roth SH; Neurosci Lett 122 (2): 225-8 (1991)]**PEER REVIEWED**

IN ADDN TO INCR VENTILATION, SMALL PARENTERAL DOSES OF SULFIDE IN LAB ANIMALS PRODUCE FLEETING RISE FOLLOWED BY PROFOUND (PERHAPS IRREVERSIBLE) FALL IN BLOOD PRESSURE. DEATH ... IS INVARIABLY RESULT OF CENTRAL RESP PARALYSIS. /HYDROGEN SULFIDE/
[Gosselin, R.E., H.C. Hodge, R.P. Smith, and M.N. Gleason. Clinical Toxicology of Commercial Products. 4th ed. Baltimore: Williams and Wilkins, 1976.,p. III-170]**PEER REVIEWED**

Non-Human Toxicity Values:

LC50 Rhesus monkey inhalation 700 mg/cu m/35 min.
[Lund OE, Wieland H; Int Arch Gewerbepathol Gewerbehyg 22: 46-54 (1966)]**PEER REVIEWED**

LC50 Mouse inhalation 1500 mg/cu m/18 min
[Verschueren, K. Handbook of Environmental Data of Organic Chemicals. 2nd ed. New York, NY: Van Nostrand Reinhold Co., 1983. 745]**PEER REVIEWED**

LC50 Mouse inhalation 380 mg/cu m/410 min
[Verschueren, K. Handbook of Environmental Data of Organic Chemicals. 2nd ed. New York, NY: Van Nostrand Reinhold Co., 1983. 745]**PEER REVIEWED**

LC50 Mouse inhalation 96 mg/cu m/804 min
[Verschueren, K. Handbook of Environmental Data of Organic Chemicals. 2nd ed. New York, NY: Van Nostrand Reinhold Co., 1983. 745]**PEER REVIEWED**

LC50 Mouse inhalation 24 mg/cu m/ > 960 min
[Verschueren, K. Handbook of Environmental Data of Organic Chemicals. 2nd ed. New York, NY: Van Nostrand Reinhold Co., 1983. 745]**PEER REVIEWED**

LC50 Rat inhalation 1500 mg/cu m/14 min
[Verschueren, K. Handbook of Environmental Data of Organic Chemicals. 2nd ed. New York, NY: Van Nostrand Reinhold Co., 1983. 745]**PEER REVIEWED**

LC50 Rat inhalation 380 mg/ cu m > 960 min
[Verschueren, K. Handbook of Environmental Data of Organic Chemicals. 2nd ed. New York, NY: Van Nostrand Reinhold Co., 1983. 745]**PEER REVIEWED**

Ecotoxicity Values:

TLm Asellus sp 0.111 mg/l/96 hr /Conditions of bioassay not specified/
[Verschueren, K. Handbook of Environmental Data of Organic Chemicals. 2nd ed. New York, NY: Van Nostrand Reinhold Co., 1983. 744]**PEER REVIEWED**

TLm Crangonyx sp 1.07 mg/l/96 hr /Conditions of bioassay not specified/
[Verschueren, K. Handbook of Environmental Data of Organic Chemicals. 2nd ed. New York, NY: Van Nostrand Reinhold Co., 1983. 744]**PEER REVIEWED**

TLm Gammarus sp 0.84 mg/l/96 hr /Conditions of bioassay not specified/
[Verschueren, K. Handbook of Environmental Data of Organic Chemicals. 2nd ed. New York, NY: Van Nostrand Reinhold Co., 1983. 744]**PEER REVIEWED**

LC50 Fly inhalation 380 mg/cu m/ > 960 min
[Verschueren, K. Handbook of Environmental Data of Organic Chemicals. 2nd ed. New York, NY: Van Nostrand Reinhold Co., 1983. 745]**PEER REVIEWED**

LC50 Fly inhalation 1500 mg/cum/7 min
[Verschueren, K. Handbook of Environmental Data of Organic Chemicals. 2nd ed. New York, NY: Van Nostrand Reinhold Co., 1983. 745]**PEER REVIEWED**

TLm Lepomis macrochirus (bluegill sunfish) eggs 0.0190 mg/l/72 hr at 21-22 deg C in a flow through bioassay
[Verschueren, K. Handbook of Environmental Data of Organic Chemicals. 2nd ed. New York, NY: Van Nostrand Reinhold Co., 1983. 745]**PEER REVIEWED**

TLm Lepomis macrochirus (bluegill sunfish) 35 day old fry 0.0131 mg/l/96 hr at 21-22 deg C in a flow through bioassay
[Verschueren, K. Handbook of Environmental Data of Organic Chemicals. 2nd ed. New York, NY: Van Nostrand Reinhold Co., 1983. 745]**PEER REVIEWED**

TLm Lepomis macrochirus (bluegill sunfish) juveniles 0.0478 mg/l/96 hr at 21-22 deg C in a flow through bioassay
[Verschueren, K. Handbook of Environmental Data of Organic Chemicals. 2nd ed. New York, NY: Van Nostrand Reinhold Co., 1983. 745]**PEER REVIEWED**

TLm Lepomis macrochirus (bluegill sunfish) adults 0.0448 mg/l/96 hr at 21-22 deg C in a flow through bioassay
[Verschueren, K. Handbook of Environmental Data of Organic Chemicals. 2nd ed. New York, NY: Van Nostrand Reinhold Co., 1983. 745]**PEER REVIEWED**

TLm Pimephales promelas (fathead minnow) 0.0071-0.55 mg/l/96 hr at 6-24 deg C in a flow through bioassay
[Verschueren, K. Handbook of Environmental Data of Organic Chemicals. 2nd ed. New York, NY: Van Nostrand Reinhold Co., 1983. 745]**PEER REVIEWED**

TLm Salvelinus fontinalis (brook trout) 0.0216-0.038 mg/l/96 hr at 8-12.5 deg C in a flow through bioassay
[Verschueren, K. Handbook of Environmental Data of Organic Chemicals. 2nd ed. New York, NY: Van Nostrand Reinhold Co., 1983. 745]**PEER REVIEWED**

Metabolism/Pharmacokinetics:

Metabolism/Metabolites:

With the body, H2S is metabolized by oxidation, methylation, and reaction with metallo- or disulfide-containing proteins.
[Sullivan, J.B. Jr., G.R. Krieger (eds.). Hazardous Materials Toxicology-Clinical Principles of Environmental Health. Baltimore, MD: Williams and Wilkins, 1992. 712]**PEER REVIEWED**

... In the bloodstream the gas is converted to alkali sulfide. The hydrosulfide radical is excreted by the lungs and in urine. Part of the sulfide is oxidized to sulfate and thiosulfate ... .
[Booth, N.H., L.E. McDonald (eds.). Veterinary Pharmacology and Therapeutics. 5th ed. Ames, Iowa: Iowa State University Press, 1982. 959]**PEER REVIEWED**

Absorption, Distribution & Excretion:

...the lung rather than the skin is the primary route of absorption. The dermal absorption of hydrogen sulfide is minimal. Results from animal inhalation studies indicate that H2S is distributed in the body to the brain, liver, kidneys, pancreas, and small intestine.
[Sullivan, J.B. Jr., G.R. Krieger (eds.). Hazardous Materials Toxicology-Clinical Principles of Environmental Health. Baltimore, MD: Williams and Wilkins, 1992. 712]**PEER REVIEWED**

... Hydrogen sulfide is readily absorbed through the skin, lung and digestive tract lining. ... Some of the sulfide may be trapped by natural disulfides in the bloodstream. Some sulfide is also excreted as iron sulfide in feces.
[Booth, N.H., L.E. McDonald (eds.). Veterinary Pharmacology and Therapeutics. 5th ed. Ames, Iowa: Iowa State University Press, 1982. 959]**PEER REVIEWED**

FIRST ACID DISSOCIATION CONSTANT OF HYDROGEN SULFIDE IS ABOUT 1X10-7 MOLAR SO THAT IN BODY FLUIDS DISSOCIATED & UNDISSOCIATED HYDROGEN SULFIDE EXIST IN ABOUT EQUAL PROPORTIONS. UNDISSOCIATED ACID, HOWEVER, PENETRATES BIOLOGICAL MEMBRANES MORE RAPIDLY THAN THE HYDROSULFIDE ANION. /HYDROGEN SULFIDE/
[Gosselin, R.E., R.P. Smith, H.C. Hodge. Clinical Toxicology of Commercial Products. 5th ed. Baltimore: Williams and Wilkins, 1984.,p. III-200]**PEER REVIEWED**

Mechanism of Action:

HYDROSULFIDE ANION (HS-) ... FORMS COMPLEX WITH METHEMOGLOBIN KNOWN AS SULFMETHEMOGLOBIN, WHICH IS ANALOGOUS TO CYANMETHEMOGLOBIN. ... DISSOCIATION CONSTANT FOR SULFMETHEMOGLOBIN HAS BEEN EST AS 6X10-6 MOLES/L WHERE AS THE DISSOCIATION CONSTANT FOR CYANMETHEMOGLOBIN IS ABOUT 2X10-8 MOLES/L. DESPITE LOWER BINDING AFFINITY FOR SULFIDE, INDUCED METHEMOGLOBINEMIA PROVIDES UNEQUIVOCAL PROTECTION AGAINST DEATH FROM ACUTE SULFIDE POISONING IN ANIMALS.
[Klaassen, C.D., M.O. Amdur, Doull J. (eds.). Casarett and Doull's Toxicology. The Basic Science of Poisons. 5th ed. New York, NY: McGraw-Hill, 1995. 351]**PEER REVIEWED**

THE ABSORPTION OF HYDROGEN SULFIDE (H2S) GAS BY SCIATIC NERVE BUNDLES FROM RANA PIPIENS PRODUCES AN ANESTHETIC EFFECT OF SHORT DURATION. UNLIKE HYDROGEN CYANIDE THERE IS NO INDICATION THAT HYDROGEN SULFIDE INHIBITS THE ENERGY METABOLISM OF THE NERVE CELLS, EXCEPT POSSIBLY WHEN THE NERVES ARE EXPOSED TO EXTREMELY HIGH SULFIDE CONCENTRATIONS. A MODE OF ACTION FOR HYDROGEN SULFIDE IS PROPOSED.
[BECK JF ET AL; TOXICOLOGY 26 (1): 37-45 (1983)]**PEER REVIEWED**

...interferes with the function of oxidative enzymes, mainly cytochrome oxidase, and results in tissue hypoxia.
[Rom, W.N. (ed.). Environmental and Occupational Medicine. 2nd ed. Boston, MA: Little, Brown and Company, 1992. 546]**PEER REVIEWED**

Hydrogen sulfide is a ... potent inhibitor of the cytochrome oxidase system ... .
[Ellenhorn, M.J., S. Schonwald, G. Ordog, J. Wasserberger. Ellenhorn's Medical Toxicology: Diagnosis and Treatment of Human Poisoning. 2nd ed. Baltimore, MD: Williams and Wilkins, 1997. 1491]**PEER REVIEWED**

SUDDEN DEATH FROM INHALATION OF LARGE CONCN OF HYDROGEN SULFIDE DUE TO INHIBITION OF CELLULAR RESP IN VITAL TISSUES, PARTICULARLY BRAIN. ... APPARENTLY ... INHIBIT/S/ CYTOCHROME OXIDASE, THUS INHIBITING ELECTRON-TRANSPORT SYSTEM.
[Booth, N.H., L.E. McDonald (eds.). Veterinary Pharmacology and Therapeutics. 5th ed. Ames, Iowa: Iowa State University Press, 1982. 9602]**PEER REVIEWED**

Interactions:

Pregnant rats were exposed to 0, 100, 200, 400 or 800 ppm of carbon disulfide (CS2), 100 ppm hydrogen sulfide (H2S) alone or in combination with 400 or 800 ppm CS2, 6 hr/day during days 6-20 gestation. Maternal reproduction and fetal parameters were evaluated on gestational day 21. Treatment with 100 or 200 ppm CS2 or with 100 ppm H2S caused no maternal toxicity or adverse effects on the developing embryo or fetus. Exposure to 400 or 800 ppm CS2 resulted in a low incidence of club foot and in a significant reduction of maternal weight gain. Significant incr in unossified sternebrae occurred at 800 ppm CS2 and reduction of fetal body weight at 400 and 800 ppm CS2. The latter effect was enhanced by combination with 100 ppm H2S. ... At levels of exposure associated with maternal toxicity, CS2 leads to an incr in incidence of club foot and to fetal toxicity which is enhanced by simultaneous exposure to H2S.
[Saillenfait AM, et al; Toxicol Lett 48 (1): 57-66 (1989)]**PEER REVIEWED**

Hydrogen sulfide ... is produced endogenously in mammalian tissues from L-cysteine mainly by two pyridoxal-5'-phosphate dependent enzymes, cystathionine beta-synthetase and cystathionine gamma-lyase. ... Cystathionine beta-synthetase in the brain produces H2S, and that H2S facilitates the induction of hippocampal long term potentiation by enhancing NMDA receptor activity. ... mRNA for another H2S producing enzyme, cystathionine gamma-lyase is expressed in the ileum, portal vein and thoracic aorta. The ileum also expresses cystathionine beta-synthetase mRNA. These tissues produce H2S, and this production is blocked by cystathionine beta-synthetase and cystathionine gamma-lyase specific inhibitors. Although exogenously applied H2S alone relaxed these smooth muscles, much lower concn of H2S greatly enhanced the smooth muscle relaxation induced by NO in the thoracic aorta. These observations suggest that the endogenous H2S may regulate smooth muscle tone in synergy with NO.
[Hosoki R, et al; Biochem Biophys Res Commun 237 (3): 527-31 (1997)]**PEER REVIEWED**

Pharmacology:

Interactions:

Pregnant rats were exposed to 0, 100, 200, 400 or 800 ppm of carbon disulfide (CS2), 100 ppm hydrogen sulfide (H2S) alone or in combination with 400 or 800 ppm CS2, 6 hr/day during days 6-20 gestation. Maternal reproduction and fetal parameters were evaluated on gestational day 21. Treatment with 100 or 200 ppm CS2 or with 100 ppm H2S caused no maternal toxicity or adverse effects on the developing embryo or fetus. Exposure to 400 or 800 ppm CS2 resulted in a low incidence of club foot and in a significant reduction of maternal weight gain. Significant incr in unossified sternebrae occurred at 800 ppm CS2 and reduction of fetal body weight at 400 and 800 ppm CS2. The latter effect was enhanced by combination with 100 ppm H2S. ... At levels of exposure associated with maternal toxicity, CS2 leads to an incr in incidence of club foot and to fetal toxicity which is enhanced by simultaneous exposure to H2S.
[Saillenfait AM, et al; Toxicol Lett 48 (1): 57-66 (1989)]**PEER REVIEWED**

Hydrogen sulfide ... is produced endogenously in mammalian tissues from L-cysteine mainly by two pyridoxal-5'-phosphate dependent enzymes, cystathionine beta-synthetase and cystathionine gamma-lyase. ... Cystathionine beta-synthetase in the brain produces H2S, and that H2S facilitates the induction of hippocampal long term potentiation by enhancing NMDA receptor activity. ... mRNA for another H2S producing enzyme, cystathionine gamma-lyase is expressed in the ileum, portal vein and thoracic aorta. The ileum also expresses cystathionine beta-synthetase mRNA. These tissues produce H2S, and this production is blocked by cystathionine beta-synthetase and cystathionine gamma-lyase specific inhibitors. Although exogenously applied H2S alone relaxed these smooth muscles, much lower concn of H2S greatly enhanced the smooth muscle relaxation induced by NO in the thoracic aorta. These observations suggest that the endogenous H2S may regulate smooth muscle tone in synergy with NO.
[Hosoki R, et al; Biochem Biophys Res Commun 237 (3): 527-31 (1997)]**PEER REVIEWED**

Environmental Fate & Exposure:

Probable Routes of Human Exposure:

Inhalation of gas, ingestion, eye, and skin contact.
[Sittig, M. Handbook of Toxic and Hazardous Chemicals and Carcinogens, 1985. 2nd ed. Park Ridge, NJ: Noyes Data Corporation, 1985. 513]**PEER REVIEWED**

MAJORITY OF OCCUPATIONAL EXPOSURES TO HYDROGEN SULFIDE RESULTED FROM ITS OCCURRENCE IN PETROLEUM, NATURAL GAS, SOIL, SEWER GAS & AS BYPRODUCT OF CHEM REACTIONS, SUCH AS MAY TAKE PLACE IN VISCOSE RAYON & CERTAIN LEATHER TANNING PROCESSES.
[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. 786]**PEER REVIEWED**

... /GAS/ RELEASED FROM SLURRY TANKS IN PIGGERIES WHEN THE SLURRY HAS AGITATED PRIOR TO PUMPING. UNDER THESE CONDITIONS GAS CAN BUILD UP TO TOXIC LEVEL (80-800 PPM); ON OCCASIONS MEN WORKING ON SITE HAVE BEEN OVERCOME.
[Humphreys, D.J. Veterinary Toxicology. 3rd ed. London, England: Bailliere Tindell, 1988. 83]**PEER REVIEWED**

LIQUID MANURE STORAGE IS A COMMON COMPONENT OF CONFINEMENT SYSTEMS FOR SWINE, BEEF, DAIRY, AND VEAL OPERATIONS. MORE THAN 85,000 PEOPLE IN IOWA AND 500,000 IN THE REST OF THE THE US WORK IN LIVESTOCK CONFINEMENT SYSTEMS THAT USE LIQUID MANURE STORAGE. ... TOXIC GASES EMANATING FROM THE LIQUID MANURE /MAY INCLUDE HYDROGEN SULFIDE/
[DONHAM KJ ET AL; J OCCUP MED 24 (2): 142-5 (1982)]**PEER REVIEWED**

GAS EXPOSURE RISK FROM COAL GASIFICATION PRODUCTS AT THE UCG PROJECT, RAWLINS, WYOMING IS DISCUSSED.
[MOORE J ET AL; PROC INT GAS RES CONF, 2ND: 1645-50 (1982)]**PEER REVIEWED**

Natural Pollution Sources:

IN SULFUR SPRINGS, volcanic gas, natural gas, and a component of crude petroleum.
[Budavari, S. (ed.). The Merck Index - An Encyclopedia of Chemicals, Drugs, and Biologicals. Whitehouse Station, NJ: Merck and Co., Inc., 1996. 823]**PEER REVIEWED**

HIGH LEVELS OF HYDROGEN SULFIDE IN A FLORIDA WELL WATER SOURCE WERE APPARENTLY RESPONSIBLE FOR ATTACKING /CORRODING/ A/C PIPE.
[National Research Council. Drinking Water & Health, Volume 4. Washington, DC: National Academy Press, 1981. 53]**PEER REVIEWED**

... GAS /PRODUCED/ FROM DECOMP MANURE ... /&/ LEAKING /SEWER/ MANHOLE COVER.
[Humphreys, D.J. Veterinary Toxicology. 3rd ed. London, England: Bailliere Tindell, 1988. 83]**PEER REVIEWED**

... /FROM/ VOLCANIC GASES IN HIGH CONCN.
[Klaassen, C.D., M.O. Amdur, Doull J. (eds.). Casarett and Doull's Toxicology. The Basic Science of Poisons. 5th ed. New York, NY: McGraw-Hill, 1995. 352]**PEER REVIEWED**

Artificial Pollution Sources:

... POLLUTANT IN ATMOSPHERE IN /VICINITY/ OF INDUSTRIAL PAPER PLANTS USING KRAFT PROCESS.
[Klaassen, C.D., M.O. Amdur, Doull J. (eds.). Casarett and Doull's Toxicology. The Basic Science of Poisons. 5th ed. New York, NY: McGraw-Hill, 1995. 353]**PEER REVIEWED**

In cigarette smoke: 40 ppm; combustion of coal: 0.0045 lb/lb coal; combustion of fuel oil: 1 lb/1,000 lb gas; combustion of natural gas: 0.13 lb/1,000 lb gas; In municipal sewer air: 0.2-10 ppm.
[Verschueren, K. Handbook of Environmental Data of Organic Chemicals. 2nd ed. New York, NY: Van Nostrand Reinhold Co., 1983. 744]**PEER REVIEWED**

THERMAL DEGRADATION OF POLYPHENYLENE SULFIDE MAY YIELD HYDROGEN SULFIDE ... .
[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. 4447]**PEER REVIEWED**

Hydrogen sulfide is a by product of many industrial operations, eg, coking and the hydrodesulfurization of crude oil and of coal
[Kirk-Othmer Encyclopedia of Chemical Technology. 3rd ed., Volumes 1-26. New York, NY: John Wiley and Sons, 1978-1984.,p. V26 1131 (1985)]**PEER REVIEWED**

Guidotti TL; Occupat Med 46 (5): 367-71 (1996)... Hydrogen sulfide is produced in pulp mills. ...
**PEER REVIEWED**

Environmental Fate:

Atmospheric Fate: The lifetime of hydrogen sulfide (H2S) is affected by ambient temperature and other atmospheric variables including humidity, sunshine, and presence of other pollutants. The decreased temperatures and decreased levels of hydroxide in northern regions (e.g. Alberta, Canada) in winter increase the residence time of H2S in air.
[Bottenheim JW, Strausz OP; Environ Sci Technol (14): 709-718 (1980) as cited in USEPA; Health and Environmental Effects Profile for Hydrogen Sulfide p.4-4 (1986) ECAO-CIN-026A]**PEER REVIEWED**

Once released into the atmosphere, hydrogen sulfide will behave like many other gaseous pollutants and be dispersed and eventually removed. Residence times in the atmosphere range from about one day to more than 40 days, depending upon season, latitude, and atmospheric conditions.
[Nat'l Research Council Canada; Hydrogen Sulfide in the Atmospheric Environment p.52 (1981) NRCC No. 18467]**PEER REVIEWED**

Environmental Biodegradation:

Microorganisms in soil and water are involved in oxidation-reduction reactions which oxidize hydrogen sulfide to elemental sulfur. Members of the genera Beggiatoa, Thioploca, and Thiotrix function in transition zones between aerobic and anaerobic conditions where both molecular oxygen and hydrogen sulfide are found. /Also/ some photosynthetic bacteria oxidize hydrogen sulfide to elemental sulfur. Members of the families Chlorobiaceae and Chromatiaceae (purple sulfur bacteria) are obligate aerobes and are phototropic, and are found in waters with high H2S concentrations. The interactions of these organisms form part of the global sulfur cycle.
[USEPA; Health and Environmental Effects Profile for Hydrogen Sulfide p.4-4 (1986) ECAO-CIN-026A]**PEER REVIEWED**

Environmental Abiotic Degradation:

Hydrogen sulfide does not absorb solar radiation reaching the tropsphere. It does not, therefore, undergo photolysis or react photochemically with oxygen. ... The primary chemical transformation of hydrogen sulfide in the atmosphere is oxidation by oxygen containing radicals to sulfur dioxide and sulfates.
[Nat'l Research Council Canada; Hydrogen Sulfide in the Atmospheric Environment p.52, 54 (1981) NRCC No. 18467]**PEER REVIEWED**

Environmental Bioconcentration:

Does not have bioaccumulation or food chain contamination potential.
[Environment Canada; Tech Info for Problem Spills: Hydrogen Sulphide (Draft) p.1 (1981)]**PEER REVIEWED**

Soil Adsorption/Mobility:

Anhydrous hydrogen sulfide has a boiling point of 60.3 deg C at 1 atm. Consequently, when it is spilled onto soil, much will evaporate. However, since it is very soluble in water, the presence of water in soil or falling as precipitation at the time of the spill may contribute to movement in the soil. If the soil surface is saturated with moisture at the time of the spill as might be the case after a rainfall, the spill chemical will runoff and/or evaporate away.
[Environment Canada; Tech Info for Problem Spills: Hydrogen Sulphide (Draft) p.66 (1981)]**PEER REVIEWED**

Volatilization from Water/Soil:

Anhydrous hydrogen sulfide has a boiling point of -60.3 deg C at a pressure of 1 atmosphere. Consequently, when it is spilled onto soil, much will evaporate.
[Environment Canada; Tech Info for Problem Spills: Hydrogen Sulphide (Draft) p.66 (l981)]**PEER REVIEWED**

Atmospheric Concentrations:

Ambient levels of hydrogen sulfide tend to be low, in the range of 0.001 mg/m3. Pollution episodes have reached levels of nearly 0.5 mg/cu m (0.7 ppm) in levels as high as 14.3 mg/cu m (20 ppm). At least one release in Poza Rica, Mexico emitted lethal levels of gas.
[USEPA; Health Assessment Document for Hydrogen Sulfide p. 1-2 (1986) ECAO-CIN-026A (Draft)]**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 100 lb or 45.4 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 (7/1/97)]**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. Hydrogen sulfide 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:

U135; As stipulated in 40 CFR 261.33, when hydrogen sulfide, 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 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).
[40 CFR 261.33 (7/1/97)]**PEER REVIEWED**

Clean Water Act Requirements:

Designated as a hazardous substance under section 311(b)(2)(A) of the Federal Water Pollution Control Act and further regulated by the Clean Water Act Amendments of 1977 and 1978. These regulations apply to discharges of this substance.
[40 CFR 116.4 (7/1/88)] **QC REVIEWED**

State Drinking Water Guidelines:

(WI) WISCONSIN 30 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:

H2-S
[The Merck Index. 10th ed. Rahway, New Jersey: Merck Co., Inc., 1983. 697]**PEER REVIEWED**

Molecular Weight:

34.08
[Lide, D.R. (ed.). CRC Handbook of Chemistry and Physics. 76th ed. Boca Raton, FL: CRC Press Inc., 1995-1996. 823]**PEER REVIEWED**

Color/Form:

Colorless gas [Shipped as a liquefied compressed gas].
[NIOSH. NIOSH Pocket Guide to Chemical Hazards. DHHS (NIOSH) Publication No. 94-116. Washington, D.C.: U.S. Government Printing Office, June 1994. 170]**PEER REVIEWED**

Odor:

Strong odor of rotten eggs [Note: Sense of smell becomes rapidly fatigued & can NOT be relied upon to warn of the continuous presense of hydrogen sulfide].
[NIOSH. NIOSH Pocket Guide to Chemical Hazards. DHHS (NIOSH) Publication No. 94-116. Washington, D.C.: U.S. Government Printing Office, June 1994. 170]**PEER REVIEWED**

Offensive odor.
[Lewis, R.J., Sr (Ed.). Hawley's Condensed Chemical Dictionary. 12th ed. New York, NY: Van Nostrand Rheinhold Co., 1993 617]**PEER REVIEWED**

Taste:

SWEETISH TASTE
[Budavari, S. (ed.). The Merck Index - An Encyclopedia of Chemicals, Drugs, and Biologicals. Whitehouse Station, NJ: Merck and Co., Inc., 1996. 823]**PEER REVIEWED**

Boiling Point:

-60.33 DEG C
[Budavari, S. (ed.). The Merck Index - An Encyclopedia of Chemicals, Drugs, and Biologicals. Whitehouse Station, NJ: Merck and Co., Inc., 1996. 823]**PEER REVIEWED**

Melting Point:

-85.49 DEG C
[Budavari, S. (ed.). The Merck Index - An Encyclopedia of Chemicals, Drugs, and Biologicals. Whitehouse Station, NJ: Merck and Co., Inc., 1996. 823]**PEER REVIEWED**

Corrosivity:

Anhydrous hydrogen sulfide has low general corrosivity toward carbon steel, aluminum, Inconel, Stellite and 300-series stainless steels at moderate temperatures. Temperatures greater than ca 260 deg C can produce severe sulfidation of carbon steel. Wet hydrogen sulfide can be quite corrosive to carbon steel.
[Kirk-Othmer Encyclopedia of Chemical Technology. 4th ed. Volumes 1: New York, NY. John Wiley and Sons, 1991-Present.,p. V23 281]**PEER REVIEWED**

Critical Temperature & Pressure:

Critical temperature: 373.56K; 100.4 deg C; 212.7 deg F Critical pressure; 9010 KPa; 90.1 bar; 1 306.5 psia; 88.9 atm
[Matheson Gas Products; Matheson Gas Data Book 6th Ed p.408 (1980)]**PEER REVIEWED**

Critical temperature: 373.2 K; critical pressure: 8.94 MPa.
[Lide, D.R. (ed.). CRC Handbook of Chemistry and Physics. 76th ed. Boca Raton, FL: CRC Press Inc., 1995-1996.,p. 6-56]**PEER REVIEWED**

Density/Specific Gravity:

1.5392 G/L AT 0 DEG C @ 760 MM HG; GAS: 1.19 (AIR= 1.00)
[Budavari, S. (ed.). The Merck Index - An Encyclopedia of Chemicals, Drugs, and Biologicals. Whitehouse Station, NJ: Merck and Co., Inc., 1996. 823]**PEER REVIEWED**

Dissociation Constants:

pKa1 = 7.04; pKa2 = 11.96
[Budavari, S. (ed.). The Merck Index - An Encyclopedia of Chemicals, Drugs, and Biologicals. Whitehouse Station, NJ: Merck and Co., Inc., 1996. 823]**PEER REVIEWED**

Heat of Vaporization:

Molar enthalpy of vaporization: 14.08 kJ/mol at 25 deg C; 18.67 kJ/mol at -59.55 deg C.
[Lide, D.R. (ed.). CRC Handbook of Chemistry and Physics. 76th ed. Boca Raton, FL: CRC Press Inc., 1995-1996.,p. 6-116]**PEER REVIEWED**

pH:

FRESHLY PREPARED WATER SOLN: 4.5
[Budavari, S. (ed.). The Merck Index - An Encyclopedia of Chemicals, Drugs, and Biologicals. Whitehouse Station, NJ: Merck and Co., Inc., 1996. 823]**PEER REVIEWED**

Solubilities:

SOL IN CARBON DISULFIDE
[Weast, R.C. (ed.) Handbook of Chemistry and Physics. 69th ed. Boca Raton, FL: CRC Press Inc., 1988-1989.,p. B-95]**PEER REVIEWED**

1 G DISSOLVES IN 94.3 ML ABSOLUTE ALCOHOL @ 20 DEG C
[Budavari, S. (ed.). The Merck Index - An Encyclopedia of Chemicals, Drugs, and Biologicals. Whitehouse Station, NJ: Merck and Co., Inc., 1996. 823]**PEER REVIEWED**

1 G DISSOLVES IN 48.5 ML ETHER AT 20 DEG C
[Budavari, S. (ed.). The Merck Index - An Encyclopedia of Chemicals, Drugs, and Biologicals. Whitehouse Station, NJ: Merck and Co., Inc., 1996. 823]**PEER REVIEWED**

In water, 3980 mg/l at 20 deg C.
[Kirk-Othmer Encyclopedia of Chemical Technology. 4th ed. Volumes 1: New York, NY. John Wiley and Sons, 1991-Present.,p. V23 277]**PEER REVIEWED**

Soluble in glycerol, gasoline, kerosene, carbon disulfide, crude oil.
[Budavari, S. (ed.). The Merck Index - An Encyclopedia of Chemicals, Drugs, and Biologicals. Whitehouse Station, NJ: Merck and Co., Inc., 1996. 823]**PEER REVIEWED**

Soluble in certain polar organic solvents, notably methanol, acetone, propylene carbonate, sulfolane, tributyl phosphate, various glycols, and glycol ethers. N-Methylpyrrolidine dissolves 49 ml/g at 20 deg C at atmospheric pressure.
[Kirk-Othmer Encyclopedia of Chemical Technology. 4th ed. Volumes 1: New York, NY. John Wiley and Sons, 1991-Present.,p. V23 276]**PEER REVIEWED**

Spectral Properties:

INDEX OF REFRACTION (LIQ): 1.374
[Weast, R.C. (ed.) Handbook of Chemistry and Physics. 69th ed. Boca Raton, FL: CRC Press Inc., 1988-1989.,p. B-95]**PEER REVIEWED**

Vapor Density:

1.189
[Sax, N.I. Dangerous Properties of Industrial Materials. 6th ed. New York, NY: Van Nostrand Reinhold, 1984. 1552]**PEER REVIEWED**

Vapor Pressure:

1.56X10+4 mm Hg @ 25 deg C /from experimentally-derived coefficients/
[Daubert, T.E., R.P. Danner. Physical and Thermodynamic Properties of Pure Chemicals Data Compilation. Washington, D.C.: Taylor and Francis, 1989.]**PEER REVIEWED**

Viscosity:

Gas at 101.325 KPa at 25 deg C; 0.012 8 m Pa.S; 0.012 8 cP.
[Matheson Gas Products; Matheson Gas Data Book 6th Ed p.408 (1980)]**PEER REVIEWED**

Other Chemical/Physical Properties:

Triple Point; 187.62 K; -85.5 deg C; -122.0 deg F: Absolute density, Gas at 101.325 kPa at 25 deg C 1.506 kg/cu m: Relative density, Gas at 101.325 kPa at 25 deg C (Air = 1) 1.188: Density, Liquid at Saturation Pressure at -60.3 deg C 0.960 kg/l: Critical Temperature 373.56 K; 100.4 deg C; 212.7 deg F: Critical Volume 2.867 dm3/kg: Critical Density 0.349 kg/dm3: Critical Compressibility Factor 0.283: Latent Heat of Fusion at -85.5 deg C 2 376.5 J/mol; 69 741.2 J/kg; 16.67 kcal/kg Thermal Conductivity, Gas at 101.325 kPa at 15.6 deg C 0.014 004 W/(m.K); 33.5 x 10-6 cal/(sq cm deg C) Solubility In Water at 101.325 kOPa at 25 deg C 2.257 cu m/1 cu m water: Index of Refraction, Gas at 101.325 kPa, ND at 25 deg C 1.000 584 5: Dielectric Constant; Gas at 0 deg C, 101.325 kPa 1.004: Liquid at -78.5 deg C 9.05.
[Matheson Gas Products; Matheson Gas Data Book 6th Ed p.408 (1980)]**PEER REVIEWED**

Water solutions of hydrogen sulfide are not stable, absorbed oxygen causes the formation of elemental sulfur and the solutions become turbid rapidly. In a 50:50 v/v mixture of glycerol and water the precipitation of sulfur is retarded considerably.
[Budavari, S. (ed.). The Merck Index - An Encyclopedia of Chemicals, Drugs, and Biologicals. Whitehouse Station, NJ: Merck and Co., Inc., 1996. 823]**PEER REVIEWED**

Burns in air with a pale blue flame.
[Budavari, S. (ed.). The Merck Index - An Encyclopedia of Chemicals, Drugs, and Biologicals. Whitehouse Station, NJ: Merck and Co., Inc., 1996. 823]**PEER REVIEWED**

Chemical Safety & Handling:

DOT Emergency Guidelines:

Health: TOXIC; Extremely Hazardous. May be fatal if inhaled or absorbed through skin. Initial odor may be irritating or foul and may deaden your sense of smell. Contact with gas or liquefied gas may cause burns, severe injury and/or frostbite. Fire will produce irritating, corrosive and/or toxic gases. Runoff from fire control may cause pollution. /Hydrogen sulfide; Hydrogen sulfide, liquefied/
[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-117]**QC REVIEWED**

Fire or explosion: These materials are extremely flammable. May form explosive mixtures with air. May be ignited by heat, sparks or flames. Vapors from liquefied gas are initially heavier than air and spread along ground. Vapors may travel to source of ignition and flash back. Runoff may create fire or explosion hazard. Containers may explode when heated. Ruptured cylinders may rocket. /Hydrogen sulfide; Hydrogen sulfide, liquefied/
[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-117]**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. Many gases are heavier than air and will spread along ground and collect in low or confined areas (sewers, basements, tanks). Keep out of low areas. Ventilate closed spaces before entering. /Hydrogen sulfide; Hydrogen sulfide, liquefied/
[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-117]**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. /Hydrogen sulfide; Hydrogen sulfide, liquefied/
[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-117]**QC REVIEWED**

Evacuation: ... Fire: If tank, rail car or tank truck is involved in a fire, ISOLATE for l600 meters (1 mile) in all directions; also, consider initial evacuation for 1600 meters (1 mile) in all directions. /Hydrogen sulfide; Hydrogen sulfide, liquefied/
[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-117]**QC REVIEWED**

Fire: DO NOT EXTINGUISH A LEAKING GAS FIRE UNLESS LEAK CAN BE STOPPED. Small fires: Dry chemical, CO2, water spray or regular foam. Large fires: Water spray, fog or regular foam. Move containers from fire area if you can do it without risk. Damaged cylinders should be handled only by specialists. Fire involving tanks: 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. Do not direct water at source of leak or safety devices; icing may occur. Withdraw immediately in case of rising sound from venting safety devices or discoloration of tank. ALWAYS stay away from tanks engulfed in fire. /Hydrogen sulfide; Hydrogen sulfide, liquefied/
[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-117]**QC REVIEWED**

Spill or leak: ELIMINATE all ignition sources (no smoking, flares, sparks or flames in immediate area). All equipment used when handling the product must be grounded. Fully encapsulating, vapor protective clothing should be worn for spills and leaks with no fire. Do not touch or walk through spilled material. Stop leak if you can do it without risk. Use water spray to reduce vapors or divert vapor cloud drift. Avoid allowing water runoff to contact spilled material. Do not direct water at spill or source of leak. If possible, turn leaking containers so that gas escapes rather than liquid. Prevent entry into waterways, sewers, basements or confined areas. Isolate area until gas has dispersed. Consider igniting spill or leak to eliminate toxic gas concerns. /Hydrogen sulfide; Hydrogen sulfide, liquefied/
[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-117]**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. In case of contact with liquefied gas, thaw frosted parts with lukewarm water. Keep victim warm and quiet. Keep victim under observation. Effects of contact or inhalation may be delayed. Ensure that medical personnel are aware of the material(s) involved, and take precautions to protect themselves. /Hydrogen sulfide; Hydrogen sulfide, liquefied/
[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-117]**QC REVIEWED**

Initial Isolation and Protective Action Distances: Small Spills (from a small package or small leak from a large package): First, ISOLATE in all Directions 30 meters (100 feet); then, PROTECT persons Downwind during DAY 0.2 kilometers (0.1 miles) and NIGHT 0.3 kilometers (0.2 miles). LARGE SPILLS (from a large package or from many small packages): First, ISOLATE in all Directions 215 meters (700 feet); then, PROTECT persons Downwind during DAY 1.4 kilometers (0.9 miles) and NIGHT 4.3 kilometers (2.7 miles).
[U.S. Department of Transportation. 2000 Emergency Response Guidebook. RSPA P 5800.8 Edition. Washington, D.C: U.S. Government Printing Office, 2000,p. TABLE]**QC REVIEWED**

Odor Threshold:

0.05 ppm
[Dreisbach, R.H. Handbook of Poisoning. 12th ed. Norwalk, CT: Appleton and Lange, 1987. 257]**PEER REVIEWED**

Detection limit in air: 1.30x10-1 ppm (purity not specified)
[Fazzalari, F.A. (ed.). Compilation of Odor and Taste Threshold Values Data. ASTM Data Series DS 48A (Committee E-18). Philadelphia, PA: American Society for Testing and Materials, 1978. 87]**PEER REVIEWED**

Detection limit in air: 1.80x10-4 ppm (purity not specified)
[Fazzalari, F.A. (ed.). Compilation of Odor and Taste Threshold Values Data. ASTM Data Series DS 48A (Committee E-18). Philadelphia, PA: American Society for Testing and Materials, 1978. 87]**PEER REVIEWED**

Detection limit in air: 4.7x10-3 ppm (chemically pure)
[Fazzalari, F.A. (ed.). Compilation of Odor and Taste Threshold Values Data. ASTM Data Series DS 48A (Committee E-18). Philadelphia, PA: American Society for Testing and Materials, 1978. 87]**PEER REVIEWED**

Odor low = 0.0007 cu m; Odor high = 0.0140 cu m; irritating conc. 14.00 mg/cu m.
[Ruth JH; Am Ind Hyg Assoc J 47: A-142-51 (1986)]**PEER REVIEWED**

... Olfactory fatigue level: 100 ppm. Olfactory nerve paralysis: 150 ppm. ...
[Sullivan, J.B. Jr., G.R. Krieger (eds.). Hazardous Materials Toxicology-Clinical Principles of Environmental Health. Baltimore, MD: Williams and Wilkins, 1992. 712]**PEER REVIEWED**

Skin, Eye and Respiratory Irritations:

The direct action of H2S on mucous membranes is usually observed first by symptoms of eye irritation, resulting from local inflammation of the conjunctiva and cornea. Acute inflammation of conjunctiva accompanied by lacrimation and mucopurulent exudate is not uncommon. In severe cases, corneal erosion with blurred vision may also occur. Occasionally, corneal ulceration may occur, resulting in impaired vision. Since the cornea is affected together with the conjunctiva in many instances, keratoconjunctivitis rather than conjunctivitis more accurately describes the ophthalmologic effects of H2S exposure. In general, irritation of the eyes occurs at a concentration of H2S of 50 ppm; however, conjunctivitis or "sore eyes" have been observed upon exposures in the range of 5-100 ppm.
[Sullivan, J.B. Jr., G.R. Krieger (eds.). Hazardous Materials Toxicology-Clinical Principles of Environmental Health. Baltimore, MD: Williams and Wilkins, 1992. 713]**PEER REVIEWED**

Eye and respiratory tract irritation is noticeable at 50 ppm. ...
[Sullivan, J.B. Jr., G.R. Krieger (eds.). Hazardous Materials Toxicology-Clinical Principles of Environmental Health. Baltimore, MD: Williams and Wilkins, 1992. 712]**PEER REVIEWED**

Irritant to eyes and mucuous membranes ...
[Lewis, R.J. Sax's Dangerous Properties of Industrial Materials. 9th ed. Volumes 1-3. New York, NY: Van Nostrand Reinhold, 1996. 1843]**PEER REVIEWED**

The irritant effect of H2S extends rather uniformly throughout the entire respiratory tract, resulting in rhinitis, pharyngitis, laryngitis, bronchitis, and pneumonia. Cough, sore throat, hoarseness, runny nose, and chest tightness are the most common symptoms of exposure between 50 and 250 ppm.
[Sullivan, J.B. Jr., G.R. Krieger (eds.). Hazardous Materials Toxicology-Clinical Principles of Environmental Health. Baltimore, MD: Williams and Wilkins, 1992. 713]**PEER REVIEWED**

Fire Potential:

FLAMMABLE GAS. LOW IGNITION ENERGY.
[Fire Protection Guide to Hazardous Materials. 12 ed. Quincy, MA: National Fire Protection Association, 1997.,p. 49-79]**QC REVIEWED**

NFPA Hazard Classification:

FLAMMABILITY: 4. 4= VERY FLAMMABLE GASES, VERY VOLATILE FLAMMABLE LIQ, & MATERIALS THAT IN FORM OF DUSTS OR MISTS READILY FORM EXPLOSIVE MIXTURES WHEN DISPERSED IN AIR. SHUT OFF FLOW OF GAS OR LIQ & KEEP COOLING WATER STREAMS ON EXPOSED TANKS OR CONTAINERS. USE WATER SPRAY CAREFULLY IN VICINITY OF DUSTS SO AS NOT TO CREATE DUST CLOUDS.
[Fire Protection Guide to Hazardous Materials. 12 ed. Quincy, MA: National Fire Protection Association, 1997.,p. 325-59]**QC REVIEWED**

Flammability: 4. 4= This degree includes flammable gases, pyrophoric liquids, and Class IA flammable liquids. The preferred method of fire attack is to stop the flow of material or to protect exposures while allowing the fire to burn itself out.
[Fire Protection Guide to Hazardous Materials. 12 ed. Quincy, MA: National Fire Protection Association, 1997.,p. 325-8]**QC REVIEWED**

REACTIVITY: 0. 0= MATERIALS WHICH ARE NORMALLY STABLE EVEN UNDER FIRE EXPOSURE CONDITIONS & WHICH ARE NOT REACTIVE WITH WATER. NORMAL FIRE FIGHTING PROCEDURES MAY BE USED.
[Fire Protection Guide to Hazardous Materials. 12 ed. Quincy, MA: National Fire Protection Association, 1997.,p. 325-59]**QC REVIEWED**

Flammable Limits:

LOWER: 4.0; UPPER: 44% (1% by vol)
[Fire Protection Guide to Hazardous Materials. 12 ed. Quincy, MA: National Fire Protection Association, 1997.,p. 325-59]**QC REVIEWED**

Autoignition Temperature:

500 DEG F (260 DEG C)
[Fire Protection Guide to Hazardous Materials. 12 ed. Quincy, MA: National Fire Protection Association, 1997.,p. 325-59]**QC REVIEWED**

Fire Fighting Procedures:

STOP FLOW OF GAS. USE WATER TO KEEP FIRE EXPOSED CONTAINERS COOL & TO PROTECT MEN EFFECTING SHUT OFF.
[National Fire Protection Association. Fire Protection Guide on Hazardous Materials. 9th ed. Boston, MA: National Fire Protection Association, 1986.,p. 49-54]**PEER REVIEWED**

Do not extinguish fire unless flow can be stopped. Use water in flooding quantities as fog. Apply water from as far a distance as possible. Cool all affected containers with flooding quantities of water. Use water spray to knock-down vapors.
[Association of American Railroads. Emergency Handling of Hazardous Materials in Surface Transportation. Washington, DC: Association of American Railroads, Bureau of Explosives, 1994. 586]**PEER REVIEWED**

Evacuation: If fire becomes uncontrollable or container is exposed to direct flame - consider evacuation of one-half (1/2) mile radius.
[Association of American Railroads. Emergency Handling of Hazardous Materials in Surface Transportation. Washington, DC: Association of American Railroads, Bureau of Explosives, 1994. 586]**PEER REVIEWED**

Firefighting Hazards:

HEAVIER THAN AIR ... & MAY TRAVEL CONSIDERABLE DISTANCE TO SOURCE OF IGNITION & FLASHBACK.
[National Fire Protection Association. Fire Protection Guide on Hazardous Materials. 9th ed. Boston, MA: National Fire Protection Association, 1986.,p. 49-54]**PEER REVIEWED**

Explosive Limits & Potential:

Lower explosive limit: 4.3% Upper explosive limit: 45.5%
[Sullivan, J.B. Jr., G.R. Krieger (eds.). Hazardous Materials Toxicology-Clinical Principles of Environmental Health. Baltimore, MD: Williams and Wilkins, 1992. 716]**PEER REVIEWED**

Moderately explosive when exposed to heat or flame. Explodes on contact with oxygen difluoride; nitrogen trichloride; bromine pentafluoride; chlorine trifluoride; dichlorine oxide; silver fulminate. Potentially explosive reaction with copper + oxygen. Explosive reaction when heated with perchloryl fluoride (above 100 degrees C); oxygen (above 280 degrees C).
[Lewis, R.J. Sax's Dangerous Properties of Industrial Materials. 9th ed. Volumes 1-3. New York, NY: Van Nostrand Reinhold, 1996. 1844]**PEER REVIEWED**

FORMS EXPLOSIVE MIXTURES WITH AIR OVER WIDE RANGE.
[Fire Protection Guide to Hazardous Materials. 12 ed. Quincy, MA: National Fire Protection Association, 1997.,p. 49-79]**QC REVIEWED**

Hazardous Reactivities & Incompatibilities:

Fuming nitric acid reacts with incandescence with hydrogen sulfide.
[Fire Protection Guide to Hazardous Materials. 12 ed. Quincy, MA: National Fire Protection Association, 1997.,p. 491-99]**QC REVIEWED**

FORMS EXPLOSIVE REACTIONS WITH BROMINE PENTAFLUORIDE, CHLORINE TRIFLUORIDE, NITROGEN TRIIODIDE, NITROGEN TRICHLORIDE, OXYGEN DIFLUORIDE & PHENYL DIAZONIUM CHLORIDE.
[Fire Protection Guide to Hazardous Materials. 12 ed. Quincy, MA: National Fire Protection Association, 1997.,p. 491-99]**QC REVIEWED**

Addition of powdered copper to 1:2 mixture of hydrogen sulfide and oxygen causes the metal to become incandescent and ignite the explosive mixture.
[Bretherick, L. Handbook of Reactive Chemical Hazards. 4th ed. Boston, MA: Butterworth-Heinemann Ltd., 1990 1224]**PEER REVIEWED**

A mixture of /hydrogen sulfide/ with air passed over copper powder may attain red heat. Finely divided tungsten glows red hot in a stream of hydrogen sulfide.
[Bretherick, L. Handbook of Reactive Chemical Hazards. 4th ed. Boston, MA: Butterworth-Heinemann Ltd., 1990 1224]**PEER REVIEWED**

Hydrogen sulfide is rapidly oxidized and may ignite in contact with a range of metal oxides, including barium peroxide, ... copper oxide, lead dioxide, manganese dioxide, nickel oxide, silver(I)oxide, silver(II)oxide, sodium peroxide and thallium(III)oxide. In the presence of air, contact with mixtures of calcium oxide or barium oxide with mercury oxide or nickel oxide may cause vivid incandescence or explosion.
[Bretherick, L. Handbook of Reactive Chemical Hazards. 4th ed. Boston, MA: Butterworth-Heinemann Ltd., 1990 1224]**PEER REVIEWED**

When hydrogen sulfide is passed over heated chromium trioxide, decomposition occurs with incandescence.
[National Fire Protection Association. Fire Protection Guide on Hazardous Materials. 9th ed. Boston, MA: National Fire Protection Association, 1986.,p. 491M-65]**PEER REVIEWED**

Fluorine ignites in contact with hydrogen sulfide.
[Fire Protection Guide to Hazardous Materials. 12 ed. Quincy, MA: National Fire Protection Association, 1997.,p. 491-87]**QC REVIEWED**

Hydrogen sulfide ignites in contact with chlorine monoxide.
[Fire Protection Guide to Hazardous Materials. 12 ed. Quincy, MA: National Fire Protection Association, 1997.,p. 491-99]**QC REVIEWED**

Strong oxidizers, strong nitric acid, metals.
[NIOSH. NIOSH Pocket Guide to Chemical Hazards. DHHS (NIOSH) Publication No. 97-140. Washington, D.C. U.S. Government Printing Office, 1997. 170]**QC REVIEWED**

Hazardous Decomposition:

When heated to decomposition it emits highly toxic fumes of sulfoxides.
[Lewis, R.J. Sax's Dangerous Properties of Industrial Materials. 9th ed. Volumes 1-3. New York, NY: Van Nostrand Reinhold, 1996. 1844]**PEER REVIEWED**

Immediately Dangerous to Life or Health:

100 ppm
[NIOSH. NIOSH Pocket Guide to Chemical Hazards. DHHS (NIOSH) Publication No. 97-140. Washington, D.C. U.S. Government Printing Office, 1997. 170]**QC REVIEWED**

Protective Equipment & Clothing:

/WEAR/ RUBBER-FRAMED GOGGLES; APPROVED RESP PROTECTION.
[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**

THE USE OF LIQUID MANURE STORAGE FACILITIES POSES SEVERAL SERIOUS THREATS: TOXIC GAS INHALATION, ASPHYXIATION, ASPIRATION OF LIQUID MANURE, AND INFECTION. HYDROGEN SULFIDE POISONING IN A MANURE STORAGE PIT RESULTED IN THREE DEATHS. THESE ACCIDENTS CAN BE PREVENTED BY THE USE OF A SELF-CONTAINED BREATHING APPARATUS AND A SAFETY LINE, AS WELL AS THE PRESENCE OF A SECOND PERSON FOR RESCUE IF NECESSARY.
[OSBERN LN, CRAPO RO; ANN INTERN MED 95 (3): 312-4 (1981)]**PEER REVIEWED**

Wear appropriate chemical protective clothing. Wear positive pressure self-contained breathing apparatus.
[Association of American Railroads. Emergency Handling of Hazardous Materials in Surface Transportation. Washington, DC: Association of American Railroads, Bureau of Explosives, 1994. 586]**PEER REVIEWED**

Safety devices by the DOT and approved by The Bureau of Explosives are required in hydrogen sulfide service, but are prohibited on DOT 106-A800X containers. The type approved is fusible metal having a melting point of approximately 73.9 deg C (165 deg F). When the cylinder is over 30 inches long, this type of device is required in both ends of the cylinder. When this device is placed in a valve it must either be poured into the valve, making it inaccessible, or put into a round plug which screws into the back of the valve. Due to the fact that many of the fusible devices in hydrogen sulfide cylinder valves were developing pin hole leaks, Matheson has gained approval from the Bureau of Explosives to ship cylinders with valves having safety devices containing a frangible disc that is gold plated, and prevents any corrosion from taking place at the interface between the valve body and the fusible metal, thus preventing leaks from developing.
[Matheson Gas Products; Matheson Gas Data Book 6th Ed p.410 (1980)]**PEER REVIEWED**

Wear appropriate personal protective clothing to prevent the skin from becoming frozen from contact with the liquid or from contact with vessels containing the liquid.
[NIOSH. NIOSH Pocket Guide to Chemical Hazards. DHHS (NIOSH) Publication No. 97-140. Washington, D.C. U.S. Government Printing Office, 1997. 170]**QC REVIEWED**

Wear appropriate eye protection to prevent eye contact with the liquid that could result in burns or tissue damage from frostbite.
[NIOSH. NIOSH Pocket Guide to Chemical Hazards. DHHS (NIOSH) Publication No. 97-140. Washington, D.C. U.S. Government Printing Office, 1997. 170]**QC REVIEWED**

Quick drench facilities and/or eyewash fountains should be provided within the immediate work area for emergency use where there is any possibility of exposure to liquids that are extremely cold or rapidly evaporating.
[NIOSH. NIOSH Pocket Guide to Chemical Hazards. DHHS (NIOSH) Publication No. 97-140. Washington, D.C. U.S. Government Printing Office, 1997. 170]**QC REVIEWED**

Recommendations for respirator selection. Max concn for use: 100 ppm. Respirator Class(es): Any powered, air-purifying respirator with cartridge(s) providing protection against the compound of concern. Any air-purifying, full-facepiece respirator (gas mask) with a chin-style, front- or back-mounted canister providing protection against the compound of concern. Any supplied-air respirator. May require eye protection. Any self-contained breathing apparatus with a full facepiece.
[NIOSH. NIOSH Pocket Guide to Chemical Hazards. DHHS (NIOSH) Publication No. 97-140. Washington, D.C. U.S. Government Printing Office, 1997. 170]**QC REVIEWED**

Recommendations for respirator selection. Condition: Emergency or planned entry into unknown concn or IDLH conditions: 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. 170]**QC REVIEWED**

Recommendations for respirator selection. Condition: Escape from suddenly occurring respiratory hazards: Respirator Class(es): Any air-purifying, full-facepiece respirator (gas mask) with a chin-style, front- or back-mounted canister providing protection against the compound of concern. 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. 170]**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. 170]**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**

If material /is/ 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. Attempt to stop leak if without undue personnel hazard. Use water spray to knock down vapors.
[Association of American Railroads. Emergency Handling of Hazardous Materials in Surface Transportation. Washington, DC: Association of American Railroads, Bureau of Explosives, 1994. 586]**PEER REVIEWED**

Avoid breathing vapors. Keep upwind. ... 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. Approach fire with caution.
[Association of American Railroads. Emergency Handling of Hazardous Materials in Surface Transportation. Washington, DC: Association of American Railroads, Bureau of Explosives, 1994. 586]**PEER REVIEWED**

Evacuation: If material leaking (not on fire) consider evacuation of one half (1/2) mile. Radius based on amount of material spilled, location and weather conditions.
[Association of American Railroads. Emergency Handling of Hazardous Materials in Surface Transportation. Washington, DC: Association of American Railroads, Bureau of Explosives, 1994. 586]**PEER REVIEWED**

HYDROGEN SULFIDE SHOULD NEVER BE USED FROM CYLINDER WITHOUT REDUCING PRESSURE THROUGH SUITABLE REGULATOR ATTACHED DIRECTLY TO CYLINDER.
[National Research Council. Prudent Practices for Handling Hazardous Chemicals in Laboratories. Washington, DC: National Academy Press, 1981. 99]**PEER REVIEWED**

Personnel using hydrogen sulfide should work in pairs. They should wear for instantaneous use a gas mask with an all purpose canister or a light three minute unit with a self contained air supply, which can be donned quickly before evacuating the area. Operators should carry wet lead acetate paper (turns black in the presence of minute amounts of hydrogen sulfide) on their wrists or belt for detection of dangerous concentrations of gas. In addition, there should be provided multipoint air samplers with alarms for plant production units to constantly monitor the air in and around the units.
[Matheson Gas Products; Matheson Gas Data Book 6th Ed p.409 (1980)]**PEER REVIEWED**

The following specific precautions should be observed: 1. Do not store reserve stocks of hydrogen sulfide cylinders with cylinders containing oxygen or other highly oxidizing or combustible materials. 2. Ground all lines and equipment used with hydrogen sulfide. 3. Use check valves or traps to prevent suckback into the cylinder. 4. Use a cylinder size which can be conveniently emptied in a reasonably short amount of time. 5. Keep gas masks approved for hydrogen sulfide service in an area not likely to be contaminated, ready for use in case of emergency.
[Matheson Gas Products; Matheson Gas Data Book 6th Ed p.409 (1980)]**PEER REVIEWED**

Hydrogen sulfide may readily cause pipes and valves to corrode or become brittle, lines and fittings likely to contain hydrogen sulfide should be inspected frequently and receive special attention, monitoring, and maintenance to prevent leaks.
[NIOSH: Occupational Exposure to Hydrogen Sulfide; p.85 (1977) DHEW (NIOSH) Publication # 77-158]**PEER REVIEWED**

EARLY EVALUATION OF PROCESS PLANTS, SUCH AS THE CLAUS TYPE SRU (SULFUR RECOVERY UNIT), IN THE DESIGN STAGE MINIMIZES WORKER EXPOSURE TO TOXIC CHEMICALS. THE CLAUS TYPE SRU CONVERTS THE HYDROGEN SULFIDE IN REFINERY ACID GAS INTO ELEMENTAL SULFUR. THE SRU HANDLES HIGH CONCENTRATIONS OF HYDROGEN SULFIDE, SULFUR DIOXIDE AND OTHER SULFUR COMPOUNDS.
[AMARNAMI SH, POWELL RW; AM IND HYG ASSOC J 43 (1): 49-53 (1982)]**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**

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. 170]**QC REVIEWED**

Stability/Shelf Life:

WATER SOLN ARE NOT STABLE
[Budavari, S. (ed.). The Merck Index - An Encyclopedia of Chemicals, Drugs, and Biologicals. Whitehouse Station, NJ: Merck and Co., Inc., 1996. 823]**PEER 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. 162]**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.2078 (1988)]**PEER REVIEWED**

Storage Conditions:

Store in a cool, dry, well-ventilated location. Separate from oxidizing materials.
[Fire Protection Guide to Hazardous Materials. 12 ed. Quincy, MA: National Fire Protection Association, 1997.,p. 49-79]**QC REVIEWED**

Cleanup Methods:

1) REMOVE ALL IGNITION SOURCES. 2) VENTILATE AREA OF SPILL OR LEAK TO DISPERSE GAS. 3) IF IN GASEOUS FORM, STOP FLOW OF GAS. IF SOURCE OF LEAK IS CYLINDER & ... CANNOT BE STOPPED IN PLACE, REMOVE THE LEAKING CYLINDER TO A SAFE PLACE IN THE OPEN AIR, & REPAIR THE LEAK OR ALLOW THE CYCLINDER TO EMPTY. 4) IF IN LIQ FORM, ALLOW TO VAPORIZE.
[Mackison, F. W., R. S. Stricoff, and L. J. Partridge, Jr. (eds.). NIOSH/OSHA - Occupational Health Guidelines for Chemical Hazards. DHHS(NIOSH) PublicationNo. 81-123 (3 VOLS). Washington, DC: U.S. Government Printing Office, Jan. 1981. 1]**PEER REVIEWED**

METHODS FOR THE BIOLOGICAL TREATMENT OF ACID MINE DRAINAGE WERE EVALUATED. HYDROGEN SULFIDE PRODUCED BY SULFATE REDUCTION CAN POTENTIALLY REACT WITH METALS IN SOLUTION TO FORM METAL SULFIDE PRECIPITATES. THE UTILITY OF A PILOT PLANT DESIGN INCORPORATING ANAEROBIC DIGESTION, SULFATE REDUCTION, AERATION AND FINAL CLARIFICATION AND SETTLING WAS DEMONSTRATED.
[HERRICKS EE; UNIV ILL URBANA-CHAMPAIGN WATER RESOUR CENT RES REP 0 (173): 1-88 (1982)]**PEER REVIEWED**

Land spill: Dike surface flow using soil, sand bags, foamed polyurethane, or foamed concrete. Absorb bulk liquid with fly ash or cement powder. Neutralize with agricultural lime (CaO), crushed limestone (CaCO3) or sodium bicarbonate (NaHCO3).
[Association of American Railroads. Emergency Handling of Hazardous Materials in Surface Transportation. Washington, DC: Association of American Railroads, Bureau of Explosives, 1994. 586]**PEER REVIEWED**

Water spill: Neutralize with agricultural lime (CaO), crushed limestone (CaCO3), or sodium bicarbonate (NaHCO3).
[Association of American Railroads. Emergency Handling of Hazardous Materials in Surface Transportation. Washington, DC: Association of American Railroads, Bureau of Explosives, 1994. 586]**PEER REVIEWED**

Air spill: Apply water spray or mist to knock down vapors. Vapor knockdown water is corrosive or toxic and should be diked for containment.
[Association of American Railroads. Emergency Handling of Hazardous Materials in Surface Transportation. Washington, DC: Association of American Railroads, Bureau of Explosives, 1994. 586]**PEER REVIEWED**

Disposal Methods:

Generators of waste (equal to or greater than 100 kg/mo) containing this contaminant, EPA hazardous waste number U135, must conform with USEPA regulations in storage, transportation, treatment and disposal of waste.
[40 CFR 240-280, 300-306, 702-799 (7/1/89)]**PEER REVIEWED**


[USEPA; Engineering Handbook for Hazardous Waste Incineration p.3-14 (1981) EPA 68-03-3025]**PEER REVIEWED**

A potential candidate for rotary kiln incineration at a temperature range of 820 to 1,600 deg C and residence times of seconds for liquids and gases, and hours for solids.
**PEER REVIEWED**

A potential candidate for fluidized bed incineration at a temperature range of 450 to 980 deg C and residence times of seconds for liquids and gases, and longer for solids.
**PEER REVIEWED**

Occupational Exposure Standards:

OSHA Standards:

Permissible Exposure Limit: Table Z-2 Acceptable Ceiling Concentration: 20 ppm.
[29 CFR 1910.1000 (7/1/98)]**QC REVIEWED**

Permissible Exposure Limit: Table Z-2 Acceptable maximum peak above the acceptable ceiling concentration for an 8-hour shift. Concentration: 50 ppm. Maximum Duration: 10 minutes once, only if no other meas. exp. occurs.
[29 CFR 1910.1000 (7/1/98)]**QC REVIEWED**

Vacated 1989 OSHA PEL TWA 10 ppm (14 mg/cu m); STEL 15 ppm (21 mg/cu m) is still enforced in some states.
[NIOSH. NIOSH Pocket Guide to Chemical Hazards. DHHS (NIOSH) Publication No. 97-140. Washington, D.C. U.S. Government Printing Office, 1997. 365]**QC REVIEWED**

Threshold Limit Values:

8 hr Time Weighted Avg (TWA): 10 ppm; 15 min Short Term Exposure Limit (STEL): 15 ppm.
[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. 36]**QC REVIEWED**

Notice of Intended Change for 2002: These substances, with their corresponding values and notations, comprise those for which a limit has been proposed for the first time or for which a change in the Adopted value is proposed. In each case, the proposed values should be considered trial values for the year following ratification by the ACGIH Board of Directors. If, during the year, no evidence comes to light that questions the appropriateness of these proposals, the values will be reconsidered for adoption as TLVs. 8 hr Time Weighted Avg (TWA): 5 ppm.
[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. 63]**QC REVIEWED**

NIOSH Recommendations:

Recommended Exposure Limit: 10 Min Ceiling Value: 10 ppm (15 mg/cu m).
[NIOSH. NIOSH Pocket Guide to Chemical Hazards. DHHS (NIOSH) Publication No. 97-140. Washington, D.C. U.S. Government Printing Office, 1997. 170]**QC REVIEWED**

Immediately Dangerous to Life or Health:

100 ppm
[NIOSH. NIOSH Pocket Guide to Chemical Hazards. DHHS (NIOSH) Publication No. 97-140. Washington, D.C. U.S. Government Printing Office, 1997. 170]**QC REVIEWED**

Other Occupational Permissible Levels:

Emergency Response Planning Guidelines (ERPG): ERPG(1) 0.1 ppm (no more than mild, transient effects) for up to 1 hr exposure; ERPG(2) 30 ppm (without serious, adverse effects) for up to 1 hr exposure; ERPG(3) 100 ppm (not life threatening) up to 1 hr exposure.
[American Industrial Hygiene Association. The AIHA 1999 Emergency Response Planning Guidelines and Workplace Environmental Exposure Level Guides Handbook.American Industrial Hygiene Association. Fairfax, VA 1999. 26]**QC REVIEWED**

Manufacturing/Use Information:

Major Uses:

To produce elemental sulfur and sulfuric acid; in manuf of heavy water and other chemicals; in metallurgy; as analytical reagent.
[Budavari, S. (ed.). The Merck Index - An Encyclopedia of Chemicals, Drugs, and Biologicals. Whitehouse Station, NJ: Merck and Co., Inc., 1996. 823]**PEER REVIEWED**

IN AGRICULTURE IT IS USED AS A DISINFECTANT
[International Labour Office. Encyclopedia of Occupational Health and Safety. Vols. I&II. Geneva, Switzerland: International Labour Office, 1983. 1090]**PEER REVIEWED**

INT FOR SULFURIC ACID, ELEMENTAL SULFUR, SODIUM SULFIDE, OTHER INORGANIC SULFIDES, ADDITIVES IN EXTREME PRESSURE LUBRICANTS & CUTTING OILS & INT FOR ORGANIC SULFUR COMPD
[SRI]**PEER REVIEWED**

Manufacturers:

Elf Atochem North America, Inc., Hq, 2000 Market Street, 21st Floor, Philadelphia, PA 19103-3222, (215) 419-7000; Organic Chemicals Division; Production site: 2231 Haden Road, Houston, TX 77015, (713) 455-1211.
[SRI. 1997 Directory of Chemical Producers - United States of America. Menlo Park, CA: SRI International 1997. 677]**PEER REVIEWED**

Montana Sulphur and Chemical Co., P.O. Box 31118, Billings, MT 59107, (406) 252-9324.
[SRI. 1997 Directory of Chemical Producers - United States of America. Menlo Park, CA: SRI International 1997. 677]**PEER REVIEWED**

Morton International, Inc., Hq, 100 N. Riverside Plaza, Randolph Street and the River, Chicago, IL 60606-1598, (312) 807-2000; Adhesives and Chemical Specialties; Production site: 5724 Elder Ferry Road, P.O. Box 666, Moss Point, MS 39563.
[SRI. 1997 Directory of Chemical Producers - United States of America. Menlo Park, CA: SRI International 1997. 677]**PEER REVIEWED**

Methods of Manufacturing:

PRODUCED BY REACTING DIL SULFURIC ACID WITH IRON SULFIDE, BY HEATING HYDROGEN & SULFUR IN VAPOR PHASE, BY HEATING SULFUR WITH PARAFFIN.
[The Merck Index. 10th ed. Rahway, New Jersey: Merck Co., Inc., 1983. 697]**PEER REVIEWED**

Derivation: 1) By the action of dilute sulfuric acid on a sulfide, usually iron sulfide; 2) by direct union of hydrogen and sulfur vapor at a definite temperature and pressure; 3) as a by-product of petroleum refining.
[Lewis, R.J., Sr (Ed.). Hawley's Condensed Chemical Dictionary. 12th ed. New York, NY: Van Nostrand Rheinhold Co., 1993 617]**PEER REVIEWED**

Natural gas/synthesis gas/refinery gas/coke oven gas (solvent extraction); hydrogen + sulfur (reaction); natural gas (Lacq distillation process); natural gas + sulfur (reaction; by-product of carbon disulfide production); metallurgic coke + sulfur (reaction; coproduced with carbon disulfide).
[Ashford, R.D. Ashford's Dictionary of Industrial Chemicals. London, England: Wavelength Publications Ltd., 1994. 479]**PEER REVIEWED**

Formulations/Preparations:

Grades: Technical, 98.5%; purified, 99.5% min; CP
[Lewis, R.J., Sr (Ed.). Hawley's Condensed Chemical Dictionary. 12th ed. New York, NY: Van Nostrand Rheinhold Co., 1993 617]**PEER REVIEWED**

Consumption Patterns:

8.85X10+11 G AS AN INT FOR SULFURIC ACID (1966)
[SRI]**PEER REVIEWED**

Laboratory Methods:

Analytic Laboratory Methods:

THE TRACOR MODEL 700A HALL ELECTROLYTIC CONDUCTIVITY DETECTOR (HECD) WAS EVALUATED FOR ITS USE AS A SULFUR-SELECTIVE DETECTOR (FOR NATURAL GAS OR PESTICIDE ANALYSIS). THE OVERALL MINIMUM SELECTIVITY FOUND WAS 5.5X10+3. THE RESPONSE WAS LINEAR FOR 2-4 ORDERS OF MAGNITUDE AND THE DYNAMIC RANGE WAS 6 ORDERS OF MAGNITUDE. THE SENSITIVITY RANGED FROM 0.21-1.3 PG SULFUR/S FOR DIFFERENT COMPOUNDS ON DIFFERENT DAYS.
[GLUCK S; J CHROMATOGR SCI 20 (3): 103-8 (1982)]**PEER REVIEWED**

NIOSH S296: DETECTED IN AIR BY GAS CHROMATOGRAPHY EQUIPPED WITH FLAME PHOTOMETRIC DETECTOR IN SULFUR MODE; RANGE: 15-60 MG/CU M; PRECISION: 0.069.
[U.S. Department of Health, Education Welfare, Public Health Service. Center for Disease Control, National Institute for Occupational Safety Health. NIOSH Manual ofAnalytical Methods. 2nd ed. Volumes 1-7. Washington, DC: U.S. Government Printing Office, 1977-present.,p. V6 S296]**PEER REVIEWED**

DETECTED IN AIR BY SPECTROPHOTOMETRY AT 670 NM; SAMPLE PREPARATION: ABSORPTION & REACTION WITH METHYLENE BLUE. RANGE 8.5 TO 63 MG/CU M; PRECISION: 0.121.
[U.S. Department of Health, Education Welfare, Public Health Service. Center for Disease Control, National Institute for Occupational Safety Health. NIOSH Manual ofAnalytical Methods. 2nd ed. Volumes 1-7. Washington, DC: U.S. Government Printing Office, 1977-present.,p. V2 S4]**PEER REVIEWED**

PASSIVE COLORIMETRIC DOSIMETER TUBES FOR SUBSTANCES INCLUDING HYDROGEN SULFIDE.
[MCCONNAUGHEY PW ET AL; ASTM SPEC TECH PUBL 786 (TOXIC MATER ATMOS) 113 (1982)]**PEER REVIEWED**

Qualitative hydrogen sulfide detection has been based on the blackening of coins, keys, lead based paint, and paper moistened with lead acetate solution.
[NIOSH: Occupational Exposure to Hydrogen Sulfide; p.68 (1977) DHEW (NIOSH) Publication # 77-158]**PEER REVIEWED**

EPA Method 9030: Iodometric Method. The method is used to measure the concentration of total and dissolved sulfides in drinking, surface, and saline waters. The method does not measure acid-insoluble sulfides. Excess iodine is added to a sample which has been treated with zinc acetate to produce zinc sulfide. The excess iodine is back-titrated with sodium thiosulfate or phenylarsine oxide. The precision of the end point varies with the sample. In clean waters, it should be determined within 1 drop, which is equivalent to 0.1 mg/l in a 200 ml sample. /Total sulfide/
[USEPA/Office of Solid Waste (OSW); Test Methods for Evaluating Solid Waste, Physical/Chemical Methods SW846 Methods (1986)]**PEER REVIEWED**

Method 427C: Methylene Blue Method. The procedure is applicable at sulfide concn up to 20 mg/l. It is based on the reaction of sulfide, ferric chloride, and dimethyl-p-phenylenediamine to produce methylene blue. Ammonium phosphate is added after color development to remove ferric chlloride color. The accuracy is about + or - 10%. The standard deviation has not been determined. /Total sulfide/
[Franson MA (Ed); Standard Methods for the Examination of Water and Wastewater p.475-6 (1985)]**PEER REVIEWED**

OAQPS Method 15. Determination of Hydrogen Sulfide, Carbonyl Sulfide and Carbon Disulfide Emissions from Stationary Sources, GCFPD, emissions from tail gas control units or sulfur recovery plants.
[USEPA; EMMI. EPA's Environmental Monitoring Methods Index. Version 1.1. PC# 4082. Rockville, MD: Government Institutes (1997)]**PEER REVIEWED**

Sampling Procedures:

NIOSH S296: Analyte: Sulfide; Matrix: Air; Procedure: Adsorption on molecular sieve, thermal desorption GC-FPD.
[U.S. Department of Health, Education Welfare, Public Health Service. Center for Disease Control, National Institute for Occupational Safety Health. NIOSH Manual ofAnalytical Methods. 2nd ed. Volumes 1-7. Washington, DC: U.S. Government Printing Office, 1977-present.,p. V6 S296]**PEER REVIEWED**

ANALYTE: HYDROGEN SULFIDE; MATRIX: AIR; PROCEDURE: ABSORPTION-METHYLENE BLUE SPECTROPHOTOMETRIC; /KEEP OUT OF LIGHT/.
[U.S. Department of Health, Education Welfare, Public Health Service. Center for Disease Control, National Institute for Occupational Safety Health. NIOSH Manual ofAnalytical Methods. 2nd ed. Volumes 1-7. Washington, DC: U.S. Government Printing Office, 1977-present.,p. V2 S4]**PEER REVIEWED**

Special References:

Special Reports:

WHO; Environ Health Criteria: Hydrogen Sulfide (1981)

USEPA; Health and Environmental Effects Profile for Hydrogen Sulfide (1980) ECAO-CIN-118

NIOSH; Occupational Exposure to Hydrogen Sulfide (1977) DHEW (NIOSH) Publication #77-158

Environment Canada; Tech Info for Problem Spills: Hydrogen Sulphide (Draft) (1981)

USEPA; Health and Environmental Effects Profile for Hydrogen Sulfide (1986) ECAO-CIN-026A

Nat'l Research Council Canada; Hydrogen Sulfide in the Atmospheric Environment (1981) NRCC No. 18467

Guidotti TL; Occupat Med 46 (5): 367-71 (1996). The toxicological properties of hydrogen sulfide are reviewed.

Synonyms and Identifiers:

Synonyms:

Acide sulphhydrique
**PEER REVIEWED**

ACIDE SULFHYDRIQUE (FRENCH)
**PEER REVIEWED**

DIHYDROGEN MONOSULFIDE
**PEER REVIEWED**

DIHYDROGEN SULFIDE
**PEER REVIEWED**

Hydrogene sulphure
**PEER REVIEWED**

HYDROGEN SULFURE (FRENCH)
**PEER REVIEWED**

HYDROGEN SULPHIDE
**PEER REVIEWED**

HYDROSULFURIC ACID
**PEER REVIEWED**

IDROGENO SOLFORATO (ITALIAN)
**PEER REVIEWED**

SCHWEFELWASSERSTOFF (GERMAN)
**PEER REVIEWED**

SEWER GAS
**PEER REVIEWED**

SIARKOWODOR (POLISH)
**PEER REVIEWED**

STINK DAMP
**PEER REVIEWED**

SULFURETED HYDROGEN
**PEER REVIEWED**

SULFUR HYDRIDE
**PEER REVIEWED**

ZWAVELWATERSTOF (DUTCH)
**PEER REVIEWED**

Formulations/Preparations:

Grades: Technical, 98.5%; purified, 99.5% min; CP
[Lewis, R.J., Sr (Ed.). Hawley's Condensed Chemical Dictionary. 12th ed. New York, NY: Van Nostrand Rheinhold Co., 1993 617]**PEER REVIEWED**

Shipping Name/ Number DOT/UN/NA/IMO:

UN 1053; Hydrogen sulfide

IMO 2.1; Hydrogen sulfide

Standard Transportation Number:

49 054 10; Hydrogen sulfide

EPA Hazardous Waste Number:

U135; A toxic waste when a discarded commercial chemical product or manufacturing chemical intermediate or an off specification commercial chemical product or manufacturing chemical intermediate.

RTECS Number:

NIOSH/MX1225000

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