CHLORINE
DIOXIDE CASRN: 10049-04-4 See Occupational Exposure Standards Human Health Effects:
Evidence for Carcinogenicity: Under the current guidelines (USEPA, 1986), chlorine
dioxide is classified as Group D; not classifiable as to human
carcinogenicity because of inadequate data in humans and animals. Under the
draft Carcinogen Assessment Guidelines (USEPA, 1996), the human carcinogenicity
of chlorine dioxide cannot be determined
because no satisfactory human or animal studies assessing the chronic
carcinogenic potential of chlorine dioxide
have been located. Concentrates prepared from drinking water
treated with chlorine dioxide did not
increase the incidence of lung adenomas in strain A mice, the skin tumor
frequency in mice, or the incidence of gamma-glutamyl transpeptidase positive
foci (a measure of preneoplastic changes) in rat livers. However, chlorine dioxide did induce a hyperplastic
response in the mouse skin. Both postive and negative results have been found in
genotoxicity studies. HUMAN CARCINOGENICITY DATA: None. ANIMAL CARCINOGENICITY
DATA: None.
Human Toxicity Excerpts: ... A CONCENTRATION OF CHLORINE DIOXIDE
OF 5 PPM WAS DEFINITELY IRRITATING ... 19 PPM OF THE GAS INSIDE
A BLEACH TANK WAS MORE THAN SUFFICIENT TO CAUSE THE DEATH OF 1 WORKER (TIME OF
EXPOSURE NOT SPECIFIED) ... /INVESTIGATORS/ SUGGEST IN 1950 A MAXIMAL ACCEPTABLE
CONCENTRATION OF 1 PPM ... FOUND CONCENTRATIONS AVERAGING ... BETWEEN TRACES AND
0.25 PPM ASSOCIATED WITH SLIGHT EFFECTS ON RESPIRATORY AILMENTS ... REPORTED
BRONCHITIS AND PRONOUNCED EMPHYSEMA IN A CHEMIST AFTER REPEATEDLY EXPOSED ...
SYMPTOMS WERE INCREASING DYSPNEA AND ASTHMATIC BRONCHITIS ... .
... INVESTIGATION OF WORKERS EXPOSED FOR 5 YR TO CHLORINE DIOXIDE IN SULFITE-CELLULOSE PLANT.
CHLORINE ... ALSO PRESENT, AS WAS SULFUR DIOXIDE... SYMPTOMS & SIGNS OF
IRRITATION OF EYES & RESPIRATORY TRACT LEADING TO SLIGHT BRONCHITIS ... IN
MAJORITY ... OF WORKERS. /SOME WORKERS/ ... SHOWED IRRITATION OF GI TRACT ... .
EPIDEMIOLOGIC STUDY OF 198 PERSONS EXPOSED FOR 3 MO TO DRINKING WATER
DISINFECTED WITH CHLORINE DIOXIDE WAS
CONDUCTED, DATA FAILED TO IDENTIFY ANY SIGNIFICANT EXPOSURE-RELATED EFFECTS.
Two adults ingested 250 ml of chlorine dioxide
in water containing concn of 40 mg/l. Within 5 min of ingestion,
sudden headache, nausea, abdominal discomfort, and light-headedness were
observed ... effects disappeared within 5 min. An assessment of the safety of chronically admin chlorine water disinfectants
in man was conducted in 3 phases. Phase I, a rising dose tolerance
investigation, examined the effects of single dose incr concn admin of
disinfectants to normal healthy adult male volunteers. Phase II considered the
impact on normal subjects of 12 wk daily ingestion of the disinfectants at a
concn of 5 mg/l. In phase III, chlorite, at a concn of 5 mg/l, was admin daily
to glucose 6-phosphate dehydrogenase (G-6-PD)-deficient subjects. The study
affirmed the relative safety and tolerance of normal healthy adult males and
normal healthy adult male G-6-PD-deficient individuals to daily 12 wk ingestion
of 500 ml of chlorine disinfectants at a concn of 5 mg/l.
CHLORINE DIOXIDE & ITS ORG
REACTION PRODUCTS MAY PRESENT A HIGHER RISK FROM ACUTE TOXICITY THAN CHLORINE,
COMBINED CHLORINE, OR OZONE, BUT ITS USE MAY BE ADVANTAGEOUS WHEN THE GENERATION
OF POSSIBLY CARCINOGENIC BYPRODUCTS BY OTHER DISINFECTANTS IS CONSIDERED. /SRP:
THIS IS CURRENTLY A SUBJECT OF DEBATE/ Using records from the 1940's, the morbidity and mortality experience of
infants born in a MA community using relatively high levels of chlorine dioxide for water disinfection was
compared to that of infants in a suitable comparison community using
conventional chlorination of water. A statistically significant pos association
was found between exposure of the mother to chlorine
dioxide-treated water during pregnancy and prematurity of the
newborn. The rates of jaundice, birth defects and fetal and neonatal mortality
did not differ significantly between communities. Since chlorine dioxide represents an
alternate method of drinking water disinfection its systematic toxicity as well
as that of its disproportionation products, chlorite and chlorate, was
investigated in controlled clinical studies with volunteers and with subjects
exhibiting a low activity of glucose-6-phosphate dehydrogenase. At the dosages
applied, no adverse health effects and no changes of any of the biochemical
parameters tested could be found. Industrially men exposed to low concentrations of the gas in air have been
noted occasionally to suffer from irritation of the eyes and to see haloes about
lights, but these effects have been minor compared to respiratory irritation.
The corneas of workers seeing haloes have not been examined to determine whether
epithelial edema is present and responsible for this symptom.
Irritation of the eyes and respiratory tract leading to slight bronchitis ...
in workers. A study of the blood chemistry parameters of 20 renal dialysis patients was
undertaken when a local water district introduced chlorine dioxide as a disinfectant at the
filtration plant headworks for 12 months without informing the renal dialysis
clinic in the area of this potentially adverse change. Due to data limitations,
including changes in clinical laboratories and lack of pre-exposure data for
some patients, the analysis was focused on 17 patients for whom data was
produced by the s clinical laboratory, for 3 months of pre-exposure and 1 month
of exposure. Least-squares means of each parameter by chlorine dioxide levels of 0.0 and 1.0 mg/l at
the treatment plant were adjusted for age, sex, and creatinine. Water
purification at the clinic included passing the water through granular activated
carbon, filtration by 5 micron filters, and the use of reverse osmosis.
Chlorination products measured at the clinic after this purification and prior
to preparation of the dialysate consisted only of chlorite at the 0.02-0.08 mg/l
level. No evidence of chlorine dioxide
induced anemia was found, nor were any other biologically
significant responses observed. Study limitations include several potentially
important hematologic parameters which were not measured, the small sample size,
and three clinical laboratory changes. Workers in pulpmills can be exposed to a multitude of gases hazardous to
respiratory function, the most common of which is chlorine gas. First aid
reports of acute gas overexposure incidents (gassings) over an 8 year period
were used to generate exposure data on a group of pulpmill workers whose
respiratory function had been studied cross sectionally in 1981 and 1988. Three
hundred forty eight incidents representing 174 workers were identified, 78% of
these being treated solely by the first aid attendant with the administration of
O2 and cough suppression medication. Among 316 workers tested during a 1988
respiratory health survey, 78 had at least one chlorine or chlorine dioxide gassing incident. There was a
significant decrease in the FEV1/FVC ratio (p <0.05) as well as increased
risk for workplace associated chest symptoms in this group with at least one
gassing incident. In an age and smoking matched analysis, among workers tested
both in 1981 and 1988, there was a greater decline in FEV1/FVC ratio and MMF (p
<0.05) in the gassed group than in the nonexposed group over the 7 year
period of observation. These results emphasize the need for worker protection
against accidental chlorine gas exposures. A womangardener of 49 years of age suffered an inhalational intoxication from
chlorine dioxide while bleaching dried
flowers. Preparation of the bleaching solutions was associated with a sharp
pungent smell, coughing, pharyngeal irritation and headache. Seven hours later
increasing cough and dyspnea led to hospitalisation. Clinical findings were
tachypnoea, tachycardia, and rales of auscultation; clinical chemistry revealed
marked leucocytosis. Chest X-ray did not yield any abnormal findings. Initially
the vital capacity and forced expiratory volume in 1 sec markedly reduced and
the resistance correspondingly enhanced. Blood gas analysis showed hypoxemia
despite alveolar hyperventilation. Administration of corticosteroids resulted in
significant alleviation of complaints and in improved lung function with
stabilization in a highly normal range, as confirmed by follow-up examination
two years later. The chlorine dioxide
intoxication had been due to pH level reduction resulting from
an incorrect proportioning and handling of the individual bleaching agent
components when preparing the solution.
Human Toxicity Values: ... A CONCENTRATION OF CHLORINE DIOXIDE
OF 5 PPM WAS DEFINITELY IRRITATING ... 19 PPM OF THE GAS INSIDE
A BLEACH TANK WAS MORE THAN SUFFICIENT TO CAUSE THE DEATH OF 1 WORKER (TIME OF
EXPOSURE NOT SPECIFIED) ... .
Skin, Eye and Respiratory Irritations: MAY BE HIGHLY IRRITATING TO SKIN AND MUCOUS MEMBRANES OF RESPIRATORY TRACT.
... ... Irritation of the eyes ... respiratory irritation.
May cause irritation of the eyes, nose, & throat. ...
Medical Surveillance: Protect/ from exposure those individuals with pulmonary diseases.
Emergency Medical Treatment:
Emergency Medical Treatment:
Animal Toxicity Studies:
Evidence for Carcinogenicity: Under the current guidelines (USEPA, 1986), chlorine
dioxide is classified as Group D; not classifiable as to human
carcinogenicity because of inadequate data in humans and animals. Under the
draft Carcinogen Assessment Guidelines (USEPA, 1996), the human carcinogenicity
of chlorine dioxide cannot be determined
because no satisfactory human or animal studies assessing the chronic
carcinogenic potential of chlorine dioxide
have been located. Concentrates prepared from drinking water
treated with chlorine dioxide did not
increase the incidence of lung adenomas in strain A mice, the skin tumor
frequency in mice, or the incidence of gamma-glutamyl transpeptidase positive
foci (a measure of preneoplastic changes) in rat livers. However, chlorine dioxide did induce a hyperplastic
response in the mouse skin. Both postive and negative results have been found in
genotoxicity studies. HUMAN CARCINOGENICITY DATA: None. ANIMAL CARCINOGENICITY
DATA: None.
Non-Human Toxicity Excerpts: ... CONCENTRATIONS APPROXIMATING 0.1 PPM CHLORINE
DIOXIDE ... NO ABNORMAL REACTION IN RATS EXPOSED ... /FOR 10
WEEKS AT 5 HR/DAY/. A 90 DAY STUDY EXAMINED EFFECTS OF 20 PPM (2 MG/KG/DAY) & 200 PPM (9
MG/KG/DAY) OF CHLORINE DIOXIDE IN
DRINKING WATER OF AFRICAN GREEN MONKEYS. MINIMAL LOCAL IRRITATION OF ORAL MUCOSA
WAS OBSERVED ... PRELIMINARY REPORTS STATE THAT NO MEASURABLE TOXICITY TO
HEMATOPOIETIC SYSTEM OR OTHER SYSTEMS WAS OBSERVED ... .
Subchronic toxicity of chlorine dioxide
was studied in the African green monkey by admin in drinking
water during 30-60 days rising dose protocols. Thyroid metab was inhibited in
animals at approx 9.0 mg/kg/day. A significant decr of serum thyroxine occurred
after the 4th wk of exposure to 100 mg/l. The extent of thyroid suppression was
dose-dependent and reversible. The selective thyroid effect of chlorine dioxide was unexplained and
paradoxical, since it was rapidly reduced by oral and gastric secretions to
nonoxidizing species (presumably Cl-). IN A 2 YEAR STUDY, RATS EXPOSED TO CHLORINE DIOXIDE
IN THEIR DRINKING WATER SHOWED NO ADVERSE EFFECTS AFTER
CONSUMING 1.1 MG/KG/DAY, BUT THOSE DRINKING 11 MG/KG/DAY SHOWED A HIGHER
MORTALITY BY THE END OF THE STUDY ... . EXPOSURE OF A/J (HIGH GLUCOSE-6-PHOSPHATE DEHYDROGENASE DEFICIENCY) &
C57L/J (LOW GLUCOSE-6-PHOSPHATE DEHYDROGENASE DEFICIENCY) LAB MICE TO 100 PPM
CHLORINE DIOXIDE IN THEIR DRINKING WATER
FOR 30 DAYS PRODUCED NO CHANGES IN 11 HEMATOLOGICAL PARAMETERS. /SRP: THESE DATA
SHOW THAT GLUCOSE-6-PHOSPHATE DEHYDROGENASE DEFICIENCY DOES NOT PREDISPOSE TO
SPECIAL SENSITIVITY/ AQ CHLORINATION OF CATECHOL (4 & 8 MMOL) AT VARYING REAGENT RATIOS WAS
SHOWN TO PRODUCE HIGH MUTAGENICITY WITH THE AMES SALMONELLA STRAIN TA100. THE
MUTAGENICITY PEAKS AT 3 EQUIV CHLORINE/MOL OF CATECHOL. IF THE CHLORINE IS
REPLACED WITH EQUIV CHLORINE DIOXIDE
VERY LITTLE MUTAGENICITY IS PRODUCED. CHLORINE DIOXIDE (1, 10, 100 PPM)
GIVEN DAILY IN DRINKING WATER DECR BLOOD GLUTATHIONE, DECR OSMOTIC FRAGILITY,
& CHANGED MORPHOLOGY OF ERYTHROCYTES IN BOTH CHICKENS & RATS AFTER TWO
MO. The study was conducted to examine the effects of chlorine dioxide and its metabolites on the
formation of chloroform, tritiated thymidine incorporation in organs and hepatic
microsomal enzyme activities in rats. Male rats were admin 0, 10, or 100 mg/l
chlorine dioxide daily for 1 yr in
drinking water. Blood chloroform levels were significantly decr after 2, 10, and
12 mo of treatment. No differences in chloroform values in liver, kidney,
spleen, testes, and brain were observed. Chlorine
dioxide admin in drinking water for 3 wk inhibited the
incorporation of (3)H-thymidine into nuclei of rat testes and small intestine.
The incorporation in the liver was incr in 10 and 100 mg/l chlorine dioxide groups. Alanine hydroxylase
activity was incr in the 100 mg/l chlorine dioxide
group and hexobarbital sleep time studies showed slight decr in
the chlorine dioxide treatment groups
after 1 yr of treatment. Female rats were admin chlorine dioxide
at 0, 1, 10, and 100 mg/l daily in the drinking water for 2.5 mo
prior to and throughout gestation. A significant dose-response relation in the
decr of the numbers of implants and live fetuses was observed. Fetal wt was
significantly incr in the 100 mg/l group. Skeletal defects, such as incompletely
ossified or missing sternebrae, rudimentary ribs, and incompletely ossified
skull bones were not significantly different from controls. A few cases of
hypoplastic kidney, hydronephrosis, and dextrocardia were observed.
The toxicity of chlorine dioxide (0,
1, 10, 100, 1000 mg/l) was studied in rats. After 9 mo treatment, the osmotic
fragility of red blood cells was decr in all groups. After 9 mo, erythrocyte
counts, hematocrit, and hemoglobin were decr in all groups. Chlorine dioxide admin in drinking water for 3
mo inhibited the incorporation of (3)H-thymidine into nuclei of rat testes. This
inhibition was observed in the kidney of rats treated with 100 mg chlorine dioxide/l. The incorporation in small
intestinal nuclei was incr in rats treated with both 10 and 100 mg chlorine dioxide/l. Body wt was decr after 10
and 11 mo treatment. The incr of direct-acting mutagens after treatment of stored water of the
Rivers Rhine and Meuse with chlorine dioxide
was similar to the mutagenic effect demonstrated after
chlorination. An incr of mutagenicity in Salmonella typhimurium TA 98 after
disinfection of water was always more pronounced without metabolic activation
than with metabolic activation. Giant kelp (Macrocystis pyrifera) spores were exposed in beakers to a 25%
solution of chlorine dioxide at
concentrations ranging from 2.5 ug/l to 250 mg/l for 48 hr at 15 deg C.
Germination of M pyrifera was significantly reduced at chlorine dioxide concentrations of 25 and 250
mg/l. At the highest dose, germination was decr by about 80%. Germ tube length
was significantly reduced only at 250 mg/l. Purple sea urchin (Strongylocentrotus purpuratus) embryos were exposed in
beakers to a 25% solution of chlorine dioxide
at concentrations ranging from 2.5 ug/l to 250 mg/l for 48 hr at
15 deg C. Developmental abnormalities in the sea urchin embryos were determined
by Sedgewick-Rafter counting; abnormalities were grouped into one of five
categories: pre-hatch malformations, retarded development, post-hatch
malformations, skeletal malformations and gut malformations. Developmental
abnormalities in the sea urchin were evident only at exposure to the highest
chlorine dioxide concentration tested,
250 mg/l. Compared with the control, pre-hatch malformations were 6% higher;
retarded development, 2%; post-hatch malformations, 20%; skeletal malformations,
21%; and gut malformations, 11%. Kelp bass (Serranidae: Paralabrax clathratus) 20 hr old eggs were maintained
at 20 deg C without aeration in beakers containing chlorine dioxide at concentrations ranging
from 2.5 ug/l to 25 mg/l. Hatching occurred 40 hr post fertilization, and after
48 hr exposure in the test solutions, dead eggs and larvae and surviving larvae
were counted using a dissecting microscope. Survival of larval kelp bass was not
significantly affected by chlorine dioxide.
Non-volatile reaction products generated from the reactions of 70 mM aqueous
chlorine or chlorine dioxide with 10 mM
L-tryptophan were shown to be direct acting mutagens to Salmonella typhimurium
TA100 and TA98. Several of the fluorescent bands obtained after thin-layer
chromatographic fractionation of the XAD-2/8 resin concentrates of the reaction
mixtures were shown to be more mutagenic than the reaction mixtures using the
Ames Salmonella/microsome assay. In addition, these fractions were shown to be
capable of increasing significantly the frequency of sister chromatid exchange
in Chinese hamster ovary cells in the absence of rat liver S9 mix. GC/MS
analysis of the products in a highly mutagenic fraction of the aqueous chlorine
reaction products identified 1,1,3-trichloropropanone,
1,1,3,3-tetrachloropropanone and dichloroquinoline.
A total of 47 chemical substances including 32 synthetic food additives,
seven additives from natural sources, three trihalogenated methanes, two
fluoro-compounds for dental use, one insecticide, and two other compounds were
subjected to the micronucleus test in mice. Five compounds, ie, chlorine dioxide, maltol, potassium bromate,
sodium chlorite and sodium dehydroacetate, were found to induce micronuclei
after a single ip injection. Potassium bromate, sodium chlorite and sodium
dehydroacetate were tested further by oral administration, and potassium bromate
showed a clearly positive result. Toxicological studies dealing with recent findings of health effects of
drinking water disinfectants are reviewed. Experiments with monkeys and rodents
indicate that the biological activity of ingested disinfectants is expressed via
their chemical interaction with the mucosal epithelia, secretory products, and
nutritional contents of the alimentary tract. Evidence exists that a principal
partner of this redox interaction is the iodide of nutritional origin that is
ubiquitous in the gastrointestinal tract. Thus the observation that subchronic
exposure to chlorine dioxide in drinking
water decreases serum thyroxine levels in mammalian species can be best
explained with changes produced in the chemical form of the bioavailable iodide.
Ongoing and previously reported mechanistic studies indicate that oxidizing
agents such as chlorine-based disinfectants oxidize the basal iodide content of
the gastrointestinal tract. The resulting reactive iodine species readily
attaches to organic matter by covalent bonding. Evidence suggests that the
extent to which such iodinated organics are formed is proportional to the
magnitude of the electromotive force and stoichiometry of the redox couple
between iodide and the disinfectant. Because the extent of thyroid uptake of the
bioavailable iodide does not decrease during chlorine
dioxide ingestion, it seems that chlorine dioxide does not cause iodide
deficiency of sufficient magnitude to account for the decrease in
hormonogenesis. Absorption of one or more of iodinated molecules, eg, nutrients,
hormones, or cellular constituents of the alimentary tract having thyromimetic
or thyroid inhibitory properties, is a better hypothesis for the effects seen.
Female SENCAR mice were treated with aqueous solutions of hypochlorous acid,
sodium hypochlorite, chlorine dioxide,
and monochloramine by whole body exposure (except head) for a 10
min period for 4 days in the first experiment and for 1 day (except NH2Cl) in
the second experiment. Animals were sacrificed the day following the last
treatment (experiment 1) or on day 1, 2, 3, 4, 5, 8, 10, and 12 following
treatment (experiment 2), and skin thickness was measured by light microscopy at
X400 by use of an eyepiece micrometer. Concentrations of disinfectants were 1,
10, 100, 300, and 1000 mg/l, for experiment 1 and 1000 mg/l for experiment 2.
Thickness of the interfollicular epidermis for control animals was 15.4 + or -
1.5 micron. After 4 days of treatment at 1000 mg/l, hypochlorous acid and chlorine dioxide increased thickness to 39 +
or - 7.0 and 40.2 + or - 11.8, and sodium hypochlorite increased thickness to
25.2 + or - 6.1 micron. Only hypochlorous acid and chlorine dioxide were tested at 300 mg/L,
yielding an interfollicular epidermis thickness of 30.0 + or - 13.1 and 16.8 +
or - 0.8 micron, respectively. The response to HOCl was found to be dose
related; the minimally effective dose was 100 mg/l. In earlier, preliminary
tests to determine optimum treatment schedule, the response to hypochlorous acid
appeared to be maximal after 4 days of treatment and tended to decrease with
further treatment. The time-course study following a single treatment of 1000
mg/l hypochlorous acid, however, showed a progression of interfollicular
epidermis thickening of from 18.3 + or - 1.4 at 1 day to 30.8 + or - 8.0 at 8
days, decreasing to 19.1 + or - 6.2 micron at 12 days.
Ecotoxicity Values: LC50 Fathead minnow juvenile flow through 0.02 mg/l/96 hr
LC50 Fathead minnow adult 0.17 mg/l/96 hr /Conditions of bioassay not
specified/ LC50 Bluegill young of the year 0.15 mg/l/96 hr /Conditions of bioassay not
specified/
Metabolism/Pharmacokinetics:
Absorption, Distribution & Excretion: Chlorine dioxide is rapidly absorbed
after oral admin, and plasma levels peak within 1 hr after dosing. 43% of admin
dose was excreted in urine and feces within 72 hr. None was detected in expired
air. The plasma half-life was ... 44 hr in rats. After oral admin of Alcide (chlorine dioxide) in rats, the peak plasma
level was obtained in 8 hr. At 144 hr, radioactivity was highest in plasma
followed by lung, kidney, skin, bone marrow, stomach, ovary, duodenum, ileum,
spleen, fat, brain, liver, and carcass. Subcellular distribution revealed that
85% of the activity in the liver homogenate resided in the cytosol. 70% of total
activity in plasma was located in the trichloroacetic acid supernatant, with 30%
bound to the precipitated protein fraction. Urinary excretion accounted for most
of the (36)chlorine eliminated. Radioactivity was excreted as chlorine(-) and
chlorine dioxide(-) in urine.
Chlorine dioxide ... may be absorbed
by ingestion as well as inhalation.
Biological Half-Life: After oral admin of Alcide (chlorine dioxide) in rats, the peak plasma
level was obtained in 8 hr. The half-life for (36)Cl absorption from plasma was
8.03 hr, while the half life for (36)Cl elimination from plasma was 48.02 hr.
Pharmacology:
Environmental Fate & Exposure:
Environmental Fate: HYDROGEN PEROXIDE (H2O2), CHLORITE, CHLORATE, CL2O3, OXYGEN (O2), &
CHLORINE HAVE ALL BEEN REPORTED AS INTERMEDIATES OR PRODUCTS /OF CHLORINE DIOXIDE BREAKDOWN/. PRESUMABLY CHLORINE DIOXIDE WILL NOT PERSIST IN OPEN
BASINS OR RESERVOIRS, ALTHOUGH IT CAN REMAIN FOR DAYS IN CLEAN DISTRIBUTION
SYSTEMS. IT IS GENERALLY ACCEPTED THAT THE PREDOMINANT REACTION PRODUCT OF CHLORINE DIOXIDE IN WATER TREATMENT IS
CHLORITE & THAT CHLORATE & OTHER IONS ARE PRODUCED IN MINOR AMOUNTS ...
AN APPROXIMATELY 50% CONVERSION OF CHLORINE DIOXIDE
TO CHLORITE WAS REPORTED ... /IN/ WATER CONTAINING NATURAL HUMIC
ACIDS. CHLORINE DIOXIDE DOES NOT CAUSE
FORMATION OF TRIHALOMETHANES, DOES NOT REACT WITH AMMONIA, & DOES NOT CAUSE
FORMATION OF CHLORAMINES. IT CAN ... DISPROPORTIONATE TO CHLORATE & CHLORITE
... BY RAISING PH TO 11 OR 12 ... THIS IS NOT BELIEVED TO BE AN IMPORTANT
REACTION IN WATER UNDERGOING TREATMENT. /PRODUCTS FORMED DURING OXIDATIVE TREATMENT OF WATER/: BOTH OXYGENATED &
CHLORINATED PRODUCTS MAY BE FORMED, THE LATTER BEING FOUND MOST PROMINENTLY IN
CONNECTION WITH REACTIONS OF PHENOLIC SUBSTANCES. OTHER PRODUCTS THAT MIGHT
AFFECT HEALTH ARE QUINONES & 1,2-EPOXY COMPOUNDS.
Environmental Abiotic Degradation: SINCE CHLORITE IS FORMED AT A RATE OF 50% OF THE CHLORINE DIOXIDE DEMAND, SERIOUS CONSIDERATION
MUST BE GIVEN TO LIMITING CHLORITE FORMATION BEFORE CHLORINE DIOXIDE IS ADOPTED AS DISINFECTANT TO
REPLACE CHLORINE.
Environmental Water Concentrations: PROPOSED LIMITS OF USE OF CHLORINE DIOXIDE
WERE BASED PRIMARILY UPON ASSESSMENT OF HAZARDS OF RESIDUAL
CHLORITE. CONCERNED WITH POSSIBLE IN-VIVO METHEMOGLOBIN PRODUCTION BY CHLORITE
... RECOMMENDED THAT NO CHLORITE REACH THE DISTRIBUTION POINT.
Environmental Standards & Regulations:
FIFRA Requirements: Ninety days after publication of this notice ingredients /incl chlorine dioxide/ ... will be removed from
Reregistration List D, and all associated registrations will be cancelled ... .
Acceptable Daily Intakes: ... One may calculate the 24 hr SNARL /suggested no adverse response level/
as ... 1.2 mg/l. 7-Day exposure: ... One may calculate the SNARL /suggested no adverse
response level/ as ... 0.125 mg/l.
Federal Drinking Water Standards: EPA 800 ug/l
Federal Drinking Water Guidelines: EPA 800 ug/l
State Drinking Water Guidelines: (ME) MAINE 60 ug/l
Chemical/Physical Properties:
Molecular Formula: Cl-O2
Molecular Weight: 67.46
Color/Form: YELLOW TO REDDISH-YELLOW GAS AT ROOM TEMP SOLID CHLORINE DIOXIDE IS A
YELLOWISH-RED CRYSTALLINE MASS; LIQUID IS REDDISH-BROWN
Yellow to red gas or a red-brown liquid (below 52 degrees F) ...
Odor: UNPLEASANT ODOR SIMILAR TO CHLORINE AND NITRIC ACID
... Unpleasant odor similar to chlorine and nitric acid.
Boiling Point: 11 DEG C
Melting Point: -59 DEG C
Density/Specific Gravity: 1.642 @ 0 DEG C (LIQ)
Solubilities: IN WATER 3.01 G/L AT 25 DEG C AND AT 34.5 MM HG SOL IN ALKALINE AND SULFURIC ACID SOLN 2000 CC (GAS) IN 100 CC COLD WATER
Other Chemical/Physical Properties: IN WATER SLIGHT HYDROLYSIS TO CHLOROUS AND CHLORIC ACIDS; STRONGLY OXIDIZING
DECOMP (GAS) TO CHLORIC ACID, CHLORINE, & OXYGEN IN HOT WATER
DISSOLVES IN ALKALIES FORMING A MIXTURE OF CHLORITE & CHLORATE
Sp Gr: 3.09 g/l at 11 deg C
Chemical Safety & Handling:
DOT Emergency Guidelines: Fire or explosion: May explode from friction, heat or contamination. These
substances will accelerate burning when involved in a fire. May ignite
combustibles (wood, paper, oil, clothing, etc.). Some will react explosively
with hydrocarbons (fuels). Containers may explode when heated. Runoff may create
fire or explosion hazard. /Chlorine dioxide,
hydrate, frozen/ Health: TOXIC; inhalation, ingestion or contact (skin, eyes) with vapors,
dusts or substance may cause severe injury, burns, or death. Fire may produce
irritating and/or toxic gases. Toxic fumes or dust may accumulate in confined
areas (basement, tanks, hopper/tank cars, etc.). Runoff from fire control or
dilution water may cause pollution. /Chlorine dioxide,
hydrate, frozen/ Public safety: CALL Emergency Response Telephone Number. ... Isolate spill or
leak area immediately for at least 50 to lOO meters (160 to 330 feet) in all
directions. Keep unauthorized personnel away. Stay upwind. Keep out of low
areas. Ventilate closed spaces before entering. /Chlorine dioxide, hydrate, frozen/
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. /Chlorine dioxide, hydrate, frozen/
Evacuation: ... Fire: If tank, rail car or tank truck is involved in a fire,
ISOLATE for 800 meters (1/2 mile) in all directions; also, consider initial
evacuation for 800 meters (1/2 mile) in all directions. /Chlorine dioxide, hydrate, frozen/
Fire: Small fires: Use water. Do not use dry chemicals or foams. CO2 or Halon
may provide limited control. Large fires: Flood fire area with water from a
distance. Do not move cargo or vehicle if cargo has been exposed to heat. Move
containers from fire area if you can do it without risk. Do not get water inside
containers: a violent reaction may occur. Cool containers with flooding
quantities of water until well after fire is out. Dike fire-control water for
later disposal. ALWAYS stay away from tanks engulfed in fire. For massive fire,
use unmanned hose holders or monitor nozzles; if this is impossible, withdraw
from area and let fire burn. /Chlorine dioxide,
hydrate, frozen/ Spill or leak: Keep combustibles (wood, paper, oil, etc.) away from spilled
material. Do not touch damaged containers or spilled material unless wearing
appropriate protective clothing. Use water spray to reduce vapors or divert
vapor cloud drift. Prevent entry into waterways, sewers, basements or confined
areas. Small spills: Flush area with flooding quantities of water. Large spills:
DO NOT CLEAN-UP OR DISPOSE OF, EXCEPT UNDER SUPERVISION OF A SPECIALIST. /Chlorine dioxide, hydrate, frozen/
First aid: Move victim to fresh air. Call 911 or emergency medical service.
Apply artificial respiration if victim is not breathing. 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. Keep victim warm and quiet. Ensure that medical
personnel are aware of the material(s) involved, and take precautions to protect
themselves. /Chlorine dioxide, hydrate,
frozen/ Table of Water-Reactive Materials Which Produce Toxic Gases; Materials Which
Produce Large Amounts of Toxic-by-Inhalation (TIH) Gas(es) When Spilled in
Water. Name of Material: Chlorine dioxide,
hydrate, frozen; TIH Gas Produced: Chlorine. /Chlorine dioxide, hydrate, frozen/
Initial Isolation and Protective Action Distances (when spilled in water):
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 0.2 kilometers (0.1 miles).
LARGE SPILLS (from a large package or from many small packages): First, ISOLATE
in all Directions 30 meters (100 feet); then, PROTECT persons Downwind during
DAY 0.2 kilometers (0.1 miles) and NIGHT 0.6 kilometers (0.4 miles). /Chlorine dioxide, hydrate, frozen/
Skin, Eye and Respiratory Irritations: MAY BE HIGHLY IRRITATING TO SKIN AND MUCOUS MEMBRANES OF RESPIRATORY TRACT.
... ... Irritation of the eyes ... respiratory irritation.
May cause irritation of the eyes, nose, & throat. ...
Fire Potential: DANGEROUS; POWERFUL OXIDIZER. CONCN ABOVE 10% CAN IGNITE @ 130 DEG C. OXIDIZABLE ORGANIC DUSTS CAN LOWER
DECOMPOSITION TEMP. TO AVOID DANGEROUSLY HIGH CONCN OF THE GAS, IT IS SWEPT BY
AIR OR NITROGEN OUT OF REACTION VESSEL ... ABSORBED IN CHILLED WATER, THE FLOW
OF WHICH IS ADJUSTED TO PRODUCE A 6-10 G/L SOLN.
Fire Fighting Procedures: If material on fire or involved in fire: Use water in flooding quantities as
fog. Cool all affected containers with flooding quantities of water. Extinguish
fire using agent suitable for type of surrounding fire. (Material itself does
not burn or burns with difficulty.) /Chlorine dioxide
hydrate/ If fire becomes uncontrollable, consider evacuation of one-third mile radius.
/Chlorine dioxide hydrate/
Explosive Limits & Potential: REACTS VIOLENTLY WITH ORGANIC MATERIALS. IN CONCN IN EXCESS OF 10%, 1 ATM,
EASILY DETONATED BY SUNLIGHT, HEAT, CONTACT WITH MERCURY OR CARBON MONOXIDE.
Explosive hazard by heating, exposing to sunlight, contacting mercury or
carbon monoxide. REACTS VIOLENTLY WITH PHOSPHORUS, POTASSIUM HYDROXIDE, SULFUR, CONCN @ FROM
0.1 TO 1 ATM OF GREATER THAN 10% IN AIR EXPLODES, ALSO MERCURIC FLUORIDE,
ORGANIC MATTER, DIFLUOROAMINE. Explosive /Chlorine dioxide/ is explosive above
45 deg C even in absence of light, and subject to long induction periods due to
formation of intermediate dichlorine trioxide.
Hazardous Reactivities & Incompatibilities: Incompatibilities: Carbon monoxide, hydrogen, mercury, non-metals, phosphorus
pentachloride, potassium hydroxide. Reacts with water or steam to produce toxic & corrosive fumes of
hydrochloric acid. Organic materials, heat, phosphorus, potassium, hydroxide, sulfur, mercury,
carbon monoxide [Note: Unstable in light. A powerful
oxidizer].
Hazardous Decomposition: WHEN HEATED TO DECOMPOSITION, IT EMITS TOXIC FUMES OF /HYDROGEN CHLORIDE/.
Explosive decomposition at 100 deg C Decomposition by sparking begins to become hazardous at concentrations of
7-8% in air. The gas and liquid are violently decomposed by organic materials. The gas
will decompose at temperatures below the boiling point of water.
Immediately Dangerous to Life or Health: 5 ppm
Protective Equipment & Clothing: Recommendations for respirator selection. Max concn for use: 1 ppm:
Respirator Class: Any chemical cartridge respirator with cartridge(s) providing
protection against the compound of concern. Only nonoxidizable sorbents allowed
(not charcoal). Any supplied-air respirator. Recommendations for respirator selection. Max concn for use: 2.5 ppm:
Respirator Classes: Any supplied-air respirator operated in a continuous flow
mode. Eye protection needed. Any powered, air-purifying respirator with
cartridge(s) providing protection against the compound of concern. Eye
protection needed. Only nonoxidizable sorbents allowed (not charcoal).
Recommendations for respirator selection. Max concn for use: 5 ppm:
Respirator Classes: Any chemical cartridge respirator with a full facepiece and
cartridge(s) providing protection against the compound of concern. Only
nonoxidizable sorbents allowed (not charcoal). Any air-purifying, full-facepiece
respirator (gas mask) with a chin-style, front- or back-mounted canister
providing protection against the compound of concern. Only nonoxidizable
sorbents allowed (not charcoal). Any self-contained breathing apparatus with a
full facepiece. Any supplied-air respirator with a full facepiece.
Recommendations for respirator selection. Condition: Emergency or planned
entry into unknown concn or IDLH conditions: Respirator Classes: 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
with a full facepiece and operated in 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.
Recommendations for respirator selection. Respirator Classes: Escape from
suddenly occuring respiratory hazards: Any air-purifying, full-facepiece
respirator (gas mask) with a chin-style, front- or back-mounted canister
providing protection against the compound of concern. Only nonoxidizable
sorbents allowed (not charcoal). Any appropriate escape-type, self-contained
breathing apparatus. Wear safety glasses, rubber gloves, self-contained breathing apparatus,
working clothes. Wear appropriate personal protective clothing to prevent skin contact.
/Liquid/ Wear appropriate eye protection to prevent eye contact. /Liquid/
Eyewash fountains should be provided in areas where there is any possibility
that workers could be exposed to the substance; this is irrespective of the
recommendation involving the wearing of eye protection. /Liquid/
Facilities for quickly drenching the body should be provided within the
immediate work area for emergency use where there is a possibility of exposure.
[Note: It is intended that these facilities provide a sufficient quantity or
flow of water to quickly remove the substance from any body areas likely to be
exposed. The actual determination of what constitutes an adequate quick drench
facility depends on the specific circumstances. In certain instances, a deluge
shower should be readily available, whereas in others, the availability of water
from a sink or hose could be considered adequate.]
/Liquid/
Preventive Measures: SRP: Local exhaust ventilation should be applied wherever there is an
incidence of point source emissions or dispersion of regulated contaminants in
the work area. Ventilation control of the contaminant as close to its point of
generation is both the most economical and safest method to minimize personnel
exposure to airborne contaminants. OXIDIZABLE DUST SHOULD BE ELIMINATED BY FILTRATION. Contact lenses should not be worn when working with this chemical. /Liquid/
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.
Persons not wearing protective equipment and clothing should be restricted
from areas of spills or leaks until cleanup has been completed.
If material not on fire and not involved in fire: Keep material out of water
sources and sewers. /Chlorine dioxide
hydrate/ Personnel protection: Avoid breathing vapors. Avoid bodily contact with the
material. Do not handle broken packages unless wearing appropriate personal
protective equipment. Wash away any material which may have contacted the body
with copious amounts of water or soap and water. If contact with the material
anticipated, wear appropriate chemical protective clothing. /Chlorine dioxide hydrate/
The worker should immediately wash the skin when it becomes contaminated.
/Liquid/ Work clothing that becomes wet should be immediately removed due to its
flammability hazard.
Stability/Shelf Life: UNSTABLE IN LIGHT; STABLE IN DARK IF PURE, BUT CHLORIDES CATALYZE ITS
DECOMPOSITION EVEN IN DARK. SOLUTIONS IN PURE WATER CAN BE MAINTAINED FOR MONTHS IN CLOSED CONTAINERS.
Storage Conditions: MATERIALS WHICH ARE TOXIC AS STORED OR WHICH CAN DECOMPOSE INTO TOXIC
COMPONENTS ... SHOULD BE STORED IN A COOL, WELL VENTILATED PLACE, OUT OF THE
DIRECT RAYS OF THE SUN, AWAY FROM AREAS OF HIGH FIRE HAZARD, AND SHOULD BE
PERIODICALLY INSPECTED. INCOMPATIBLE MATERIALS SHOULD BE ISOLATED... .
Because of explosion hazard, do not keep in storage except in diluted
solution. A higher concentration of more than 10% should not be handled. Store
only in dry, cool, dark place with good temperature control.
Cleanup Methods: 1) Remove all ignition sources. 2) Ventilate area of spill or leak. 3) If in
gaseous form, stop flow of gas. If source of leak is a cylinder and leak cannot
be stopped in place, remove leaking cylinder to safe place in open air, and
repair leak or allow cylinder to empty. 4) If in liquid form, evacuate persons
not wearing protective equipment. ... Allow ... to evaporate while providing all
available ventilation. Occupational Exposure Standards:
OSHA Standards: Permissible Exposure Limit: Table Z-1 8-hr Time Weighted Avg: 0.1 ppm (0.3
mg/cu m). Vacated 1989 OSHA PEL TWA 0.1 ppm (0.3 mg/cu m); STEL 0.3 ppm (0.9 mg/cu m)
is still enforced in some states.
Threshold Limit Values: 8 hr Time Weighted Avg (TWA): 0.1 ppm; 15 min Short Term Exposure Limit
(STEL): 0.3 ppm.
NIOSH Recommendations: Recommended Exposure Limit: 10 Hr Time Weighted Avg: 0.1 ppm (0.3 mg/cu m).
Recommended Exposure Limit: 15 Min Short Term Exposure Limit: 0.3 ppm (0.9
mg/cu m).
Immediately Dangerous to Life or Health: 5 ppm
Other Occupational Permissible Levels: USSR (1973): 0.03 ppm; Sweden and Germany: 0.1 ppm.
Manufacturing/Use Information:
Major Uses: BLEACHING CELLULOSE, FLOUR, LEATHER, OILS, TEXTILES, BEESWAX; PURIFICATION OF
WATER; TASTE & ODOR CONTROL OF WATER; CLEANING AND DETANNING LEATHER; MFR OF
CHLORINE SALTS; OXIDIZING AGENT; BACTERICIDE & ANTISEPTIC
AGING ACCELERATOR IN THE MANUFACTURE OF FLOUR SWIMMING POOL WATER PURIFICATION BLEACHING AGENT FOR WOOD PULP, TALLOW WASTEWATER DISINFECTING AGENT
Manufacturers: C Brewer & Co, Ltd, Hq, 311 Pacific St, Honolulu, Oahu, HI 96817, (808)
533-4411 International Dioxcide, Inc, Hq, 136 Central Ave, Clark, NJ 07066, (201)
499-9660; Production site: 554 Ten Rod Rd, North Kingstown, RI 02852
Scott Paper Co, Hq, Scott Plaza, Philadelphia, PA 19113, (215) 522-5000;
Packaged Products Division; SD Warren Co, Division, 225 Franklin St, Boston, MA
02101; Production sites: Muskegon, MI 49443; Skowhegan, ME 04976; Westbrook, ME
04092
Methods of Manufacturing: REACTION OF SODIUM CHLORATE AND SULFURIC ACID WITH SULFUR DIOXIDE OR REACTION
OF CHLORIC ACID WITH METHANOL ... FROM CHLORINE AND SODIUM CHLORITE; POTASSIUM CHLORATE AND SULFURIC ACID;
BY PASSING NITROGEN DIOXIDE THROUGH A COLUMN OF SODIUM CHLORATE.
/FROM/ SODIUM CHLORATE, SULFURIC ACID AND METHANOL; SODIUM CHLORATE AND
SULFUR DIOXIDE; OXIDATION OF SODIUM CHLORITE WITH CHLORINE, HYDROCHLORIC ACID,
OR HYPOCHLORITE.
General Manufacturing Information: ... TEMPERATURE AFFECTS THE RATE OF INACTIVATION OF BACTERIA WITH CHLORINE DIOXIDE. A DECREASE IN DISINFECTANT
ACTIVITY WAS OBSERVED AS TEMPERATURE DECREASED FROM 30 DEG C TO 5 DEG C.
IT IS NOW USED IN DRINKING WATER TREATMENT FOR CONTROL OF PHENOLS, FOR
OXIDATION OF IRON & MANGANESE, & FOR FINAL DISINFECTION PRIOR TO
DISTRIBUTION. CHLORINE DIOXIDE IS AN EFFECTIVE
BACTERICIDE & VIRUCIDE UNDER THE PH, TEMPERATURE, & TURBIDITY THAT ARE
EXPECTED IN THE TREATMENT OF POTABLE WATER. CHLORINE DIOXIDE DOES NOT FORM
SIGNIFICANT AMT OF HALOGENATED ORG CMPD WHEN USED TO DISINFECT ACTIVATED-SLUDGE
& MAY SUPPRESS PRODUCTION OF SUCH BY-PRODUCTS WHEN USED WITH CHLORINE.
CHLORINE DIOXIDE DISINFECTION
REQUIRED LOWER DOSES & SHORTER CONTACT TIME THAN CHLORINE FOR COMPARABLE
COLIFORM REDUCTIONS. CHLORINE DIOXIDE IS RAPID
DISINFECTING AGENT & HAS SAME SURVIVAL RATIO AS CHLORINE BUT WITH MUCH LOWER
RESIDUAL CONCN WHEN CHLORINE EXISTS AS CHLORAMINES. CHLORINE DIOXIDE IS MORE EFFECTIVE VIRUCIDE
THAN CHLORINE IN SECONDARY EFFLUENT. A purified prepn of the simian retrovirus SA-11 containing mostly single
virion particles and a prepn of cell-associated SA-11 virions were tested for
their resistance to inactivation by 3 disinfectants. With chlorine dioxide both virus prepn were
inactivated more rapidly at pH 10 than 6. The inactivation of poliovirus by chlorine dioxide
is described. SINCE CHLORITE IS FORMED AT A RATE OF 50% OF THE CHLORINE DIOXIDE DEMAND, SERIOUS CONSIDERATION
MUST BE GIVEN TO LIMITING CHLORITE FORMATION BEFORE CHLORINE DIOXIDE IS ADOPTED AS DISINFECTANT TO
REPLACE CHLORINE.
Formulations/Preparations: GRADES: SOLD AS HYDRATE, IN FROZEN FORM. Alcide is a germicidal prepn which
has been shown to kill a wide range of common pathogenic bacteria as well as
fungi, in vitro. It contains sodium chlorite and lactic acid as the active
ingredients. The 2 parts are combined in equal vol immediately prior to
application resulting in the formation of chlorine
dioxide.
Laboratory Methods:
Analytic Laboratory Methods: A spectrophotometric method for the determination of residual chlorine dioxide (ClO2) in water, using the
dye, Acid Chrome Violet K (CI Nr 61710; Alizarin Violet 3R), is described. The
decolorization of Acid Chrome Violet K at 548 nm in an ammonia ammonium chloride
(NH3-NH4Cl) buffer solution of pH 8.1 to 8.5 is specific for chlorine dioxide without interference from
chlorine, chloramines, chlorite or chlorate ions in concentrations likely to be
present in treated drinking water. The detection limit for chlorine dioxide using this method is 0.02
mg/l, with a standard deviation of 0.01 mg/l. Method 9060M; The analysis of chlorine dioxide
using a classical wet method for evaluating solid wastes as
defined by EPA. Method 4500-Chlorine Dioxide B.
Iodometric Method for the determination of chlorine
dioxide in treated surface waters. A pure solution of chlorine dioxide is prepared by slowly adding
dilute sulfuric acid to a sodium chlorite solution. Contaminants such as
chlorine are removed by a sodium chlorite scrubber and passing the gas into
distilled water in a steady stream of air. Chlorine
dioxide releases free iodine from a potassium iodide solution
acidified with acetic acid or sulfuric acid. The liberated iodine is titrated
with a standard solution of sodium thiosulfate, with starch as the indicator.
Temperature and strong light affect solution stability. Minimize chlorine dioxide losses by storing stock chlorine dioxide solution in a dark
refrigerator and by preparing and titrating dilute chlorine dioxide solutions for standardization
purposes at the lowest practical temperature and in subdued light. Minimum
detectable concentration: One drop (0.05 ml) of 0.01 N sodium thiosulfate is
equivalent to 20 ug chlorine dioxide/l
(or 40 ug/l in terms of available chlorine) when a 500 ml sample is titrated.
Method 4500-Chlorine Dioxide C.
Amperometric Method I for the determination of chlorine
dioxide in water and wastewater. By performingfour titrations
with phenylarsine oxide, free chlorine, chloramines, chlorite and chlorine dioxide may be determined separately.
The first titration step consists of conversion of chlorine dioxide to chlorite and chlorate
throughaddition of sufficient sodium hydroxide to produce a pH of 12, followed
by neutralization to a pH of 7 and titration of free chlorine. In the second
titration potassium iodide is added to a sample that has been treated similarly
with alkali and had the pH adjusted to 7; titration yields free chlorine and
monochloramine. The third titration involves addition of potassium iodide and pH
adjustment to 7, followed by titration of free chlorine, monochloramine, and
one-fifth of the available chlorine dioxide.
In the fourth titration, addition of sufficient sulfuric acid to
lower the pH to 2 enables all available chlorine dioxide
and chlorite, to liberate an equivalent amount of iodine from
the added potassium iodide and thus be titrated. Minimize effects of pH, time,
and temperature of reaction by standardizing all conditions. The method
distinguished various chlorine compounds with good accuracy and precision.
Method 4500-Chlorine Dioxide D. DPD
Method for the determination of chlorine dioxide
in water and wastewater. Chlorine
dioxide appears in the first step to the extent of one-fifth of
its total available chlorine content corresponding to the reduction of chlorine dioxide to chlorite ion. When
neutralized by bicarbonate, the color thus produced corresponds to the total
available chlorine content of the chlorine dioxide.
Chlorite that did not result from a positive error equal to
twice this chlorite concentration. In evaluating mixtures of chloro-compounds,
it is necessary to convert free chlorine into chloroaminoacetic acid by adding
glycine before reacting the sample with N,N-diethyl-p-phenylenediamine (DPD)
reagent. Interference appears with oxidized manganese and chromate. Iron may
activate chlorite. This method has the ability to distinguish between chlorine dioxide and various forms of
chlorine. Method 4500-Chlorine Dioxide E.
Amperometric Method (II) (proposed) for the determination of chlorine dioxide in water and wastewater. The
equilibrium for the reduction of the chlorine species of interest by iodide is
pH-dependent. Analysis for chlorine dioxide,
chlorite, and chlorate requires determination of all the
chlorine and one-fifth of the chlorine dioxide
at pH 7; lowering sample pH to 2 and determination of the
remaining four fifths of the chlorine dioxide
and all of the chlorite; preparation of a second sample by
purging with nitrogen to remove chlorine dioxide
and by reacting with iodide at pH 7 to remove any chlorine
remaining; lowering latter sample pH to 2 and determination of all chlorine
present; and, in a third sample, determination of chlorine, chlorine dioxide, chlorite, and chlorate after
reduction in hydrochloric acid. This procedure can be to concentrated solutions
(10 to 100 mg /l) or dilute solutions (0.1 to 10 mg/l) by appropriate selection
of titrant concentration and sample size. Interferences: Iodate formation at pH
values above 4 results in a negative bias in titrating the first and second
sample. A positive bias results from oxidation of iodide to iodine in strongly
acidic solutions. The low pH of the method is favorable to manganese, copper,
and nitrite interferences. The method distinguished various chlorine compounds
with good accuracy and precision. Two diffusive samplers for monitoring chlorine and chlorine dioxide in workplace air were tested.
One sampler (sampler-A) was made of polymethyl methacrylate (plexiglass) and
contained a polytetrafluoroethylene membrane filter. The other sampler
(sampler-B) was fabricated from a three piece polystyrene aerosol cassette and
contained two teflon membrane filters that had been chemically welded to the
cassette. Both samplers used a 10 mM potassium iodide solution buffered to pH 7
with 1 mM potassium dihydrogenphosphate plus 1 mM sodium hydrogenphosphate as
the sorbent. Chlorine and chlorine dioxide
reacted with the potassium iodide solution to form chloride and
chlorite ions, respectively, which were quantitated by ion chromatography. The
ability of the samplers to collect chlorine and chlorine
dioxide was evaluated under laboratory conditions at cumulative
exposures of 0 to 10 ppm plus hours and air flow rates of 0.1 to 1 m/sec. The
detection limits for chlorine dioxide
and chlorine obtained with sampler-A were 0.02 and 0.07 ppm,
respectively. The detection limits for sampler-B were 0.016 and 0.04 ppm,
respectively. A field test was conducted at a pulp bleaching factory. Parallel
sampling with impingers was also performed at the site. Chlorine and chlorine dioxide concentrations sampled by
sampler-A ranged from 0.14 to 0.20 and 0.13 to 0.24 ppm, respectively. The
corresponding concentrations obtained with sampler-B ranged from 0.14 to 0.18
and 0.12 to 0.27 ppm. Chlorine and chlorine dioxide
concentrations obtained with the impingers were 0.10 to 0.16 and
0.062 to 0.14 ppm, respectively. The poor agreement between the data obtained
with the two samplers and the impingers was attributed to an increase in acidity
of the absorbing solution of the impingers over time.
Special References:
Special Reports: CALABRESE EJ ET AL; THE HEALTH EFFECTS OF CHLORINE
DIOXIDE AS A DISINFECTANT IN POTABLE WATER: A LITERATURE SURVEY;
J ENVIRON HEALTH 41 (1): 26-31 (1978). A REVIEW WITH 43 REFERENCES ON THE HEALTH
EFFECTS OF CHLORINE DIOXIDE AS A
DISINFECTANT IN POTABLE WATER. MASSCHELEIN WJ; CHLORINE DIOXIDE:
CHEMISTRY AND ENVIRONMENTAL IMPACT OF OXYCHLORINE COMPOUNDS;
BOOK 190 pp (1980). THIS BOOK PRESENTS A GENERAL ACCOUNTING OF PRESENT KNOWLEDGE
OF DIRECT & INDIRECT ENVIRONMENTAL IMPACT & CHEMICAL BASIS FOR TECHNICAL
USES OF OXIDES OF CHLORINE. Anderson AC et al; A brief review of the current status of alternatives to
chlorine disinfection of water; Am J Public Health 72 (11): 1290-3 (1982). This
is a review of the current status of alternatives to chlorine disinfection of
water. Couri D et al; Toxicological effects of chlorine
dioxide, chlorite and chlorate; Environ Health Perspect 46:
13-17 (1982). This is a review of the toxicological effects of chlorine dioxide with 25 references.
Synonyms and Identifiers:
Synonyms: Alcide ANTHIUM DIOXCIDE CHLORINE(IV) OXIDE CHLORINE OXIDE CHLORINE PEROXIDE CHLOROPEROXYL CHLORYL RADICAL DOXCIDE 50
Formulations/Preparations: GRADES: SOLD AS HYDRATE, IN FROZEN FORM. Alcide is a germicidal prepn which
has been shown to kill a wide range of common pathogenic bacteria as well as
fungi, in vitro. It contains sodium chlorite and lactic acid as the active
ingredients. The 2 parts are combined in equal vol immediately prior to
application resulting in the formation of chlorine
dioxide.
Shipping Name/ Number DOT/UN/NA/IMO: NA 9191; Chlorine dioxide hydrate,
frozen
Standard Transportation Number: 49 181 10; Chlorine dioxide hydrate,
frozen
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