The following information has been extracted from our CHEMINFO database, which also contains hazard control and regulatory information. [More about...] [Sample Record]

Access the complete CHEMINFO database by contacting CCOHS Client Services.

 
SECTION 1. CHEMICAL IDENTIFICATION

CHEMINFO Record Number: 714
CCOHS Chemical Name: Sulfur dioxide

Synonyms:
Bisulfite
SO2
Sulfurous acid anhydride
Sulfurous anhydride
Sulfurous oxide
Sulfur oxide
Sulphur dioxide

Chemical Name French: Dioxyde de soufre
CAS Registry Number: 7446-09-5
UN/NA Number(s): 1079
RTECS Number(s): WS4550000
EU EINECS/ELINCS Number: 231-195-2
Chemical Family: Sulfur and compounds / inorganic sulfur compound / oxide / dioxide / inorganic gas
Molecular Formula: SO2
Structural Formula: O=S=O

SECTION 2. DESCRIPTION

Appearance and Odour:
Colourless gas with a pungent, irritating odour similar to burning sulfur. Colourless liquid below -10 deg C (14 deg F).

Odour Threshold:
3 to 5 ppm (detection) (12,13); 1 to 3 ppm (detection) (5)

Warning Properties:
Not reliable: odour threshold is about the same magnitude as TLV.

Composition/Purity:
Available as a liquefied compressed gas. The anhydrous grade has a minimum purity of 99.98%.

Uses and Occurrences:
Its major use is a captive intermediate in the production of sulfuric acid. In the pulp and paper industry, sulfur dioxide is used to produce other chemicals such as chlorine dioxide and sodium hyposulfite and is also used in the bleaching of pulp. In food processing, sulfur dioxide is used for fumigating, preserving, bleaching and steeping. It is also used to reduce residual chlorine in potable water, treated sewage and industrial effluent, as an oxygen scavenger, a selective extraction solvent and as a catalyst in chemical processes. In the presence of a catalyst (e.g. nitrogen compounds), sulfur dioxide can be oxidized to sulfuric acid. Occurs as a by-product during the burning (combustion) of sulfur containing organic compounds (e.g. coal). A common component of air pollution, it is a major contributor to acid rain.


SECTION 3. HAZARDS IDENTIFICATION

EMERGENCY OVERVIEW:
Colourless gas with a pungent, irritating odour similar to burning sulfur. Colourless liquid below -10 deg C. Will not burn. COMPRESSED GAS. Cylinders or tanks may rupture and explode if heated. VERY TOXIC. May be fatal if inhaled. CORROSIVE to the eyes, skin and respiratory tract. Causes lung injury-- effects may be delayed. May cause blindness. May cause permanent scarring. May cause frostbite.

Important New Information:
NOTE: The evaluation of this chemical as a chronic toxicity hazard is under review. For additional information, contact the CHEMINFO team at cheminfo@ccohs.ca.



POTENTIAL HEALTH EFFECTS

Effects of Short-Term (Acute) Exposure

Inhalation:
Sulfur dioxide (SO2) is a gas, which is corrosive to the respiratory tract. Most inhaled SO2 only penetrates as far as the nose and throat with minimal amounts reaching the lungs unless the person is breathing heavily, breathing only through the mouth or the concentration of SO2 is high.

Sensitivity varies among people, however, short exposure (1-6 hours) to concentrations as low as 1 ppm may produce a reversible decrease in lung function.(9) A 10 to 30 minute exposure to concentrations as low as 5 ppm has produced constriction of the bronchiole tubes. Only one of eleven volunteers showed any effects at 1 ppm.(23) A 20-minute exposure to 8 ppm has produced reddening of the throat and mild nose and throat irritation.(24,25) About 20 ppm is objectionably irritating, although people have been reported to work in concentrations exceeding 20 ppm. 500 ppm is so objectionable that a person cannot inhale a single deep breath.(9) In severe cases where very high concentrations of SO2 have been produced in closed spaces, SO2 has caused severe airways obstruction, hypoxemia (insufficient oxygenation of the blood), pulmonary edema (a life threatening accumulation of fluid in the lungs), and death in minutes.(7,26,27) The effects of pulmonary edema include coughing and shortness of breath which can be delayed until hours or days after the exposure. These symptoms are aggravated by physical exertion. As a result of severe exposures, permanent lung injury may occur.(26,27)

Skin Contact:
The gas will react with moisture on the skin and can cause severe irritation or corrosive injury if the concentration is high or exposure is prolonged. Corrosive materials are capable of causing burns and blistering.
Liquid SO2 may cause burns due to freezing.(2) Symptoms of mild frostbite include numbness, prickling and itching in the affected area. The skin may become white or yellow. Blistering, necrosis (dead skin) and gangrene may develop in severe cases.

Eye Contact:
Volunteers exposed to 5.4 ppm SO2 experienced mild irritation, while 9.1 ppm cause moderate to severe irritation.(31) At 8-12 ppm, smarting of the eyes and lachrymation (tears) began. There is strong irritation at 50 ppm.(30) In severe cases, (very high concentrations in confined spaces), SO2 has caused temporary corneal burns.(27) Liquid SO2 can burn the eye and permanently affect vision. Injury from contact with liquid SO2 may not be immediately noticed by the victim because SO2 damages the nerves of the eye. Any eye contact should be treated as very serious.(30)

Ingestion:
Not applicable. Ingestion of gaseous or liquid SO2 is highly unlikely.

Effects of Long-Term (Chronic) Exposure

Lungs/Respiratory System:
Several human studies have shown that repeated exposure to low levels of SO2 (below 5 ppm) has caused permanent pulmonary impairment. This effect is probably due to repeated episodes of bronchoconstriction.(15) One study has found a decrease in lung function in smelter workers exposed for over 1 year to 1-2.5 ppm SO2. No effect was seen in the same study in workers exposed to less than 1 ppm.(32) In another study, a high incidence of respiratory symptoms was reported in workers exposed to 20-30 ppm for an average of 4 years. Workers exposed to daily average values of 5 ppm SO2 (with occasional peaks of 53 ppm) had a much higher incidence of chronic bronchitis than controls.(18)
There are numerous studies on the potential effects of SO2 as a component of air pollution.(9) These studies are difficult to interpret because of confounding factors and uncertainty about exposure concentrations.

Skin:
There are two case reports of individuals developing skin eruptions after repeated inhalation of high concentrations. In later tests, it was found that as little as a 30-minute exposure to 10 ppm SO2 or a 1-hour exposure to 4 ppm SO2 could produce the skin eruptions. The eruptions disappeared after removal from exposure. These particular reactions are probably rare as there are no other reports of this type of reaction.(5)

Carcinogenicity:

Several epidemiological studies have examined the possibility that sulfur dioxide may cause cancers such as lung cancer, stomach cancer or brain tumours. In all of the studies, there were uncontrolled confounding factors, such as concurrent exposure to other chemicals. The International Agency for Cancer (IARC) has reviewed these studies and concluded there is inadequate evidence for carcinogenicity in humans. However, there is limited evidence of carcinogenicity in animals.(18)

The International Agency for Research on Cancer (IARC) has concluded that this chemical is not classifiable as to its carcinogenicity to humans (Group 3).

The American Conference of Governmental Industrial Hygienists (ACGIH) has designated this chemical as not classifiable as a human carcinogen (A4).

The US National Toxicology Program (NTP) has not listed this chemical in its report on carcinogens.

Teratogenicity and Embryotoxicity:
No human information is available. In animal studies, no teratogenic effects were observed. However, slight fetotoxicity such as reduced birth weight and functional deficits have been reported at doses which were probably toxic to the mother.

Reproductive Toxicity:
A number of epidemiological studies have suggested that exposure to SO2 may be related to adverse reproductive effects. However, it is not clear that SO2 caused the effects observed in any of these studies.(18) There are no relevant results from animal studies.

Mutagenicity:
Conflicting results have been reported in tests on cultured human lymphocytes (white blood cells) taken from workers exposed to sulfur dioxide over several years. In all of the studies, there were serious confounding factors such as exposure to other chemicals and poorly defined control groups.(18)

Toxicologically Synergistic Materials:
Insufficient information is available. Human studies have examined the effect of exposure to SO2 along with other irritating gases such as ozone and nitrogen dioxide. No conclusive evidence of synergistic action has been seen in humans. In animal studies, it has been reported that exposure to SO2 along with soluble particles such as ferrous iron and manganese and vanadium increases the toxic action of SO2.(9)

Potential for Accumulation:
SO2 may enter the body by the respiratory tract or following dilution in saliva. Most studies in both man and animals have indicated that 40-90% or more of inhaled SO2 is absorbed in the moist upper respiratory tract. SO2 is quickly converted to sulfurous acid upon contact with moist mucous membranes. Inhaled SO2 is only slowly removed from the respiratory tract. After absorption in the blood stream, the sulfurous acid is widely distributed throughout the body, quickly converted to sulfite and bisulfite, which in turn is oxidized to sulfate and excreted in the urine.(9,14,18)


SECTION 4. FIRST AID MEASURES

Inhalation:
Take proper precautions to ensure your own safety before attempting rescue (e.g. wear appropriate protective equipment, use the buddy system). Remove source of contamination or move victim to fresh air. If breathing is difficult, oxygen may be beneficial if administered by trained personnel, preferably on a doctor's advice. DO NOT allow victim to move about unnecessarily. Symptoms of pulmonary edema can be delayed up to 48 hours after exposure. Immediately transport victim to an emergency care facility.

Skin Contact:
GAS: Take measures to prevent skin contact. If irritation occurs, flush contaminated area with lukewarm, gently running water for at least 5 minutes. If irritation persists, obtain medical attention immediately. LIQUID: Avoid direct contact. Wear chemical protective clothing, if necessary. Quickly remove victim from source of contamination and briefly flush with lukewarm, gently flowing water until the chemical is removed. DO NOT attempt to rewarm the affected area on site. DO NOT rub area or apply dry heat. Gently remove clothing or jewelry that may restrict circulation. Carefully cut around clothing that sticks to the skin and remove the rest of the garment. Loosely cover the affected area with a sterile dressing. DO NOT allow victim to drink alcohol or smoke. Quickly transport victim to an emergency care facility.

Eye Contact:
Avoid direct contact. Wear chemical protective gloves, if necessary. Remove source of contamination or move victim to fresh air. Immediately flush the contaminated eye(s) with lukewarm, gently flowing water for at least 5 minutes for the gas (20 minutes for the liquid) or until the chemical is removed, while holding the eyelid(s) open. Take care not to rinse contaminated water into the unaffected eye or onto the face. Quickly transport victim to an emergency care facility.

Ingestion:
Ingestion is not an applicable route of exposure for gases.

First Aid Comments:
Provide general supportive measures (comfort, warmth, rest).
Consult a doctor and/or the nearest Poison Control Centre for all exposures except under minor instances of inhalation or skin contact. Some recommendations in the above sections may be considered medical acts in some jurisdictions. These recommendations should be reviewed with a doctor and appropriate delegation of authority obtained, as required. All first aid procedures should be periodically reviewed by a doctor familiar with the material and its conditions of use in the workplace.



SECTION 5. FIRE FIGHTING MEASURES

Flash Point:
Not applicable (not combustible)

Lower Flammable (Explosive) Limit (LFL/LEL):
Not applicable

Upper Flammable (Explosive) Limit (UFL/UEL):
Not applicable

Autoignition (Ignition) Temperature:
Not applicable

Sensitivity to Mechanical Impact:
Not available

Sensitivity to Static Charge:
Not applicable

Combustion and Thermal Decomposition Products:
None formed

Fire Hazard Summary:
Non-flammable gas. However, heat from a surrounding fire can rupture cylinders, causing a dangerous explosion and the release of toxic sulfur dioxide gas. Cylinders have fusible metal plugs which melt at 165 deg F, releasing SO2.

Extinguishing Media:
Non-flammable gas. Use extinguishing media appropriate for surrounding fire.

Fire Fighting Instructions:
Sulfur dioxide (SO2) is not combustible. Use extinguishing media suitable for the surrounding fire. In an advanced or massive fire, evacuate area and fight fire from a safe distance or a protected location. Approach fire from upwind to avoid SO2. If fire occurs in the vicinity of SO2, use unmanned monitors and hoseholders to keep cooling streams of water on fire-exposed cylinders or tanks until well after the fire is out. If possible, isolate materials not yet involved in the fire and protect personnel. Move containers from fire area if this can be done without risk.
Tanks or cylinders should not be approached directly after they have been involved in a fire until they have completely cooled down.

Protection of Fire Fighters:
SO2 is extremely hazardous to health (inhalation and skin corrosion hazard). Do not enter without wearing specialized protective equipment suitable for the situation. Firefighter's normal protective clothing (Bunker Gear) will not provide adequate protection. A full-body encapsulating chemical protective suit with positive pressure self-contained breathing apparatus (NIOSH approved or equivalent) may be necessary.



NATIONAL FIRE PROTECTION ASSOCIATION (NFPA) HAZARD IDENTIFICATION

NFPA - Health: 3 - Short exposure could cause serious temporary or residual injury.
NFPA - Flammability: 0 - Will not burn under typical fire conditions.
NFPA - Instability: 0 - Normally stable, even under fire conditions, and not reactive with water.

SECTION 9. PHYSICAL AND CHEMICAL PROPERTIES

Molecular Weight: 64.06

Conversion Factor:
1 ppm = 2.61 mg/m3; 1 mg/m3 = 0.38 ppm at 25 deg C (calculated)

Physical State: Gas
Melting Point: -72.7 deg C (-99 deg F) (5,18)
Boiling Point: -10 deg C (14 deg F) (2,5,13)
Relative Density (Specific Gravity): Not applicable (gas)
Solubility in Water: Very soluble (11.28 g/100 mL at 20 deg C) (2)
Solubility in Other Liquids: Not applicable. In water, sulfur dioxide is rapidly converted (hydrated) to sulfurous acid which is a dibasic acid (pH less than 3) (14,18) Soluble in acetone and other ketones, methanol, ethanol, acetic acid, diethyl ether, chloroform and sulfuric acid (5)
Coefficient of Oil/Water Distribution (Partition Coefficient): Not applicable (gas)
pH Value: Not applicable. In water, SO2 is rapidly converted to sulfurous acid (pH less than 3) (14,18)
Vapour Density: 2.26 (air = 1) (2)
Vapour Pressure: 339 kPa (2543 mm Hg) at 21.1 deg C (2)
Vapour Pressure at 50 deg C: 770 kPa (7.6 atm) (5800 mm Hg) (estimated from graph) (2b)
Saturation Vapour Concentration: Not applicable (gas)
Evaporation Rate: Not applicable (gas)
Critical Temperature: 157.6 deg C (315.7 deg F) (2)
Critical Pressure: 7884 kPa (2)

SECTION 10. STABILITY AND REACTIVITY

Stability:
SO2 is extremely stable to heat, even up to 2000 deg C. Complex reactions of SO2 occur in the atmosphere. SO2 gas and its aqueous forms are oxidized to sulfuric and sulfates which contribute to air pollution.(18)

Hazardous Polymerization:
Does not occur

Incompatibility - Materials to Avoid:

NOTE: Chemical reactions that could result in a hazardous situation (e.g. generation of flammable or toxic chemicals, fire or detonation) are listed here. Many of these reactions can be done safely if specific control measures (e.g. cooling of the reaction) are in place. Although not intended to be complete, an overview of important reactions involving common chemicals is provided to assist in the development of safe work practices.


BASES (e.g. sodium hydroxide) - Violent reactions can occur.

CHLORATES (e.g. potassium chlorate) - Above 60 deg C, contact with SO2 can produce chlorine dioxide which can flash and explode. Solutions of SO2 in ethanol or ether can cause an explosion on contact with potassium chlorate at ambient temperature.(10,16)

FLUORINE - Contact can produce an explosion.(10,16)

INTERHALOGENS (e.g. bromine pentafluoride, chlorine trifluoride) - Contact can be violent and ignite or produce an explosion.(10,16)

POWDERED METALS - Finely divided (pyrophoric) chromium incandesces in SO2; pyrophoric manganese burns brilliantly on heating in gas; powdered aluminum burns in the vapour of SO2; molten sodium reacts violently with dry gas or liquid; cold sodium and moist gas react vigorously.(10,16)

METAL OXIDES (e.g. cesium oxide, stannous (tin) oxide) - Will ignite and glow on heating in the gas.(10,16)

METAL ACETYLIDES (e.g. monocesium acetylide, monopotassium acetylide) - Will ignite and glow in unheated gas.(10)

SODIUM HYDRIDE - Reacts explosively on contact, unless diluted with hydrogen.(10)

CESIUM AZIDE - Ignites on contact at ambient temperature.(10)

SILVER AZIDE - Mixtures become explosive at elevated temperatures.(10)

DIETHYL ZINC - Addition to liquid SO2 at -15 deg C leads to an explosive reaction.(10)

Hazardous Decomposition Products:
Forms an acid solution (sulfurous acid) upon contact with moisture

Conditions to Avoid:
Moisture

Corrosivity to Metals:
Anhydrous SO2 is non-corrosive to steel and other common metals. However, in the presence of moisture (water), it can corrode aluminum, steel and most common metals.(2,13)

Stability and Reactivity Comments:
In some cases, SO2 behaves as both a reducing and oxidizing agent (metals such as tin, iron and magnesium burn in SO2 to form mixed sulfides and oxides).(2)


SECTION 11. TOXICOLOGICAL INFORMATION

LC50 (rat): 2520 ppm (1-hour exposure) (1)
LC50 (mouse, male): 3000 ppm (30-minute exposure) (1)

Eye Irritation:

Temporary clouding of eyes was seen in rabbits, guinea pigs and mice exposed for 4 hours to 400 ppm. Very severe eye injury in rabbits was produced by a 5-second exposure to a stream of pure sulfur dioxide (SO2).(30)

Effects of Short-Term (Acute) Exposure:

Inhalation:
Most studies indicate that high concentrations of SO2 affect the mechanics of respiration. A dose- related narrowing of the bronchiole tubes leading to the bronchoconstriction (increased airway resistance) was seen in guinea pigs exposed to concentrations of 0.2-100 ppm (0.6-260 mg/m3) for 1 hour.(9) Exposure of male mice for up to 72 hours to concentrations around 10 ppm (26 mg/m3) produced nasal cavity injury (e.g. runny nose, ciliary loss, fluid accumulation and tissue death). The effects became more severe as exposure time was increased. Less severe effects were seen in the trachea and lungs.(12) Other studies have not reported any effects after 1 to 2-hour exposure to concentrations of less than 1 ppm (2.6 mg/m3).(9)

Effects of Long-Term (Chronic) Exposure:

Inhalation:
Exposure to 5 ppm for 225 days produced pulmonary function changes in dogs.(15) Increased swelling, secretions and reddening of the trachea, as well as decreased tracheal mucosal flow was seen in dogs exposed intermittently to 1 ppm for 12 months. There was no apparent effect on pulmonary function.(20) No adverse effects were seen in guinea pigs exposed for 22 hrs/day, 7 days/week for 52 weeks to concentrations of 0.13-5.72 ppm.(21) No adverse effects were seen in monkeys exposed for 78 weeks to 0.14-1.28 ppm.(22)

Respiratory Sensitization:
Exposure to 4.3 ppm SO2 8 hours/day for 5 days has enhanced allergic sensitization to inhaled ovalbumin (a known allergen) in guinea pigs. Further research has shown that this effect can be blocked if the animals are pre-treated with anti-inflammatory drugs.(3)

Carcinogenicity:
500 ppm SO2 was inhaled by mice (35 male, 30 female) 5 minutes/day, 5 days/week for life. Female mice showed a statistically significant increase in lung tumours. Male mice did not. There are a number of design problems with this study, for example, only one dose group and the small number of animals. The International Agency for Research on Cancer (IARC) concluded there is limited evidence for carcinogenicity in experimental animals.(18) A number of studies have investigated the possibility that SO2 can act as a cocarcinogen (promotes the carcinogenicity of other chemicals). However, these studies have been questioned because of design problems such as too few animals for statistically significant results. Therefore, there is no conclusive evidence that SO2 is a cocarcinogen.(4,18)

Teratogenicity, Embryotoxicity and/or Fetotoxicity:
Slight signs of fetotoxicity (reduced birth weight and delayed righting reflex) were seen in mice exposed to 32, 65, 125 or 250 ppm.(11,18) The authors reported no maternal toxicity. However, other studies indicated that these doses would cause significant irritation. Slight embryotoxicity (decreased fetal body weight, delayed bone development) was seen when pregnant mice were exposed to 25 ppm during days 6-15 of pregnancy. Slight embryotoxicity (minor bone variations) was also seen when pregnant rabbits were exposed to 70 ppm during days 6-15 of pregnancy. Mild maternal toxicity was seen in the pregnant mice and rabbits.(28)

Reproductive Toxicity:
In one study, there was a significant reduction in testes weight in rats whose ability to metabolize SO2 was severely compromised.(19) These results are not relevant to normal exposure situations. In a Russian study, exposure of female rats to 1.9 ppm (4.97 mg/m3) for 12 hours/day for 3 months affected the female reproductive cycle. It returned to normal within 7 months after exposure.(18) There are not enough details available to evaluate this study.

Mutagenicity:
SO2 did not induce sister chromatid exchange (SCE), chromosomal aberrations or micronucleus formation in the bone marrow of mice or Chinese hamsters in in-vivo tests.(18)
SO2 induced morphological transformation of Syrian hamster embryo cells (in-vitro).(18) Bisulfite induced both transformation and SCE, but not gene mutation, chromosomal aberrations or DNA repair synthesis in cultured mammalian cells.(14,18) SO2 and its aqueous forms gave both positive and negative results in bacterial tests.(18)

Toxicological Synergisms:
The presence of soluble particles such as ferrous iron, manganese and vanadium has increased the toxic action of inhaled SO2. It has been suggested that this may be due to conversion of SO2 to sulfurous acid by moisture, the oxidation of SO2 to sulfuric acid by catalytic metal ions, or the deeper penetration of SO2 into the lungs because of the particles.(4,9)


SECTION 16. OTHER INFORMATION

Selected Bibliography:
(1) RTECS record for sulfur dioxide. Last updated 9306
(2a) Braker, W., et al. Matheson gas data book. 6th ed. Matheson, 1980. p. 641-648
(2b) Yaws, C.L. Matheson gas data book. 7th ed. McGraw-Hill, 2001. p. 598
(3) Riedel, F., et al. SO2-Induced enhancement of inhalative allergic sensitization: inhibition by anti-inflammatory treatment. Int Arch Allergy Immunol. Vol. 98 (1992). p. 386-391
(4) Mehlman, M.A. Current toxicological information as the basis for sulfur oxide standards. Environmental Health Perspectives. Vol. 52 (1983). p. 261-266
(5) Sulfur dioxide (Hygienic Guide Series). American Industrial Hygiene Association, n.d.
(6) NIOSH pocket guide to chemical hazards. NIOSH, June 1994. p. 288-289
(7) Rabinovitch, S., et al. Clinical and laboratory features of acute sulfur dioxide inhalation poisoning : two-year follow-up (case report). American Review of Respiratory Disease. Vol. 139, no. 2 (Feb. 1989). p. 556-558
(8) Sulfur dioxide. In : Documentation of the threshold limit values and biological exposure indices. 5th ed. ACGIH, 1987. p. 542-543
(9) Ericsson, G. Health effects of sulfur oxides and particulate matter in ambient air. Scandinavian Journal of Work, Environment and Health. Vol. 9, Supplement 3 (1983)
(10) Bretherick, L. Bretherick's handbook of reactive chemical hazards. 4th ed. Butterworths, 1990. p. 1414-1415
(11) Singh, J. Neonatal development altered by maternal sulfur dioxide exposure. NeuroToxicology. Vol. 10 (1989). p. 523-527
(12) Giddens, W.E., et al. Effects of sulfur dioxide on the nasal mucosa of mice. Archives of Environmental Health. Vol. 25 (1972). p. 166-173
(13) Handbook of compressed gases. 2nd ed. Van Nostrand Reinhold Company, 1981. p. 441-449
(14) Shapiro, R. Genetic effects of bisulfite (sulfur dioxide). Mutation Research. Vol. 39 (1977). p. 149-175
(15) Sulfur Dioxide. Air contaminants Final Rule (29 CFR Part 1910). Federal Register. Vol. 54, no. 12. January 19, 1989. p. 2524-2526
(16) Fire protection guide to hazardous materials. 13th ed. Edited by A.B. Spencer, et al. National Fire Protection Association, 2002. NFPA 49; NFPA 491
(17) Forsberg, K., et al. Quick selection guide to chemical protective clothing. 4th ed. Van Nostrand Reinhold, 2002
(19) Gunnison, A.F., et al. Distribution, metabolism and toxicity of inhaled sulfur dioxide and endogenously generated sulfite in the respiratory tract of normal and sulfite oxidase- deficient rats. Journal of Toxicology and Environmental Health. Vol. 21 (1987). p. 141-162
(20) Hirsch, J.A., et al. Tracheal mucous transport in beagles after long-term exposure to 1 ppm sulfur dioxide. Archives of Environmental Health. Vol. 30 (May 1975). p. 249-253
(21) Alarie, Y., et al. Long-term continuous exposure of guinea pigs to sulfur dioxide. Archives of Environmental Health. Vol. 24 (Dec. 1970). p. 769-777
(22) Alarie, Y., et al. Long-term continuous exposure to sulfur dioxide in cynomolgus monkeys. Archives of Environmental Health. Vol. 24 (Feb. 1972). p. 115-127
(23) Frank, N.R., et al. Effects of acute controlled exposure to SO2 on respiratory mechanics in healthy male adults. Journal of Applied Physiology. Vol. 17 (Mar. 1962). p. 252-258
(24) Sandstrom, T., et al. Is the short term limit value for sulphur dioxide exposure safe? Effects of controlled chamber exposure investigated with bronchoalveolar lavage. British Journal of Industrial Medicine. Vol. 46 (1989). p. 200-203
(25) Sandstrom, T., et al. Cell response in bronchoalveolar lavage fluid after exposure to sulfur dioxide : a time-response study. American Review of Respiratory Disease. Vol. 140, no. 6 (Dec. 1989). p. 1828-1831
(26) Galea, M. Fatal sulfur dioxide inhalation. Canadian Medical Association Journal. Vol. 91 (Aug. 1964). p. 345-347
(27) Charan, N.B., et al. Pulmonary injuries associated with acute sulfur dioxide inhalation. American Review of Respiratory Disease. Vol. 119, no. 4 (Apr. 1979). p. 555-560
(28) Murray, F.J., et al. Teratogenic potential of sulfur dioxide and carbon monoxide in mice and rabbits. In : Developmental toxicology of energy-related pollutants. Proceedings of the Seventeenth Annual Hanford Biology Symposium : held in Richland, Washington, October 17-19, 1977. p. 469-478
(29) Air sampling instruments for evaluation of atmospheric contaminants. 7th ed. ACGIH, 1989. p. 474-476, 507-581
(30) Grant, W.M. Toxicology of the eye. 3rd ed. Charles C. Thomas, 1986. p. 862-865
(31) Hine, C.H., et al. Eye irritation from air pollution. Journal of the Air Pollution Control Association. Vol 10, no. 1 (Feb. 1960). p. 17-20
(32) Smith, T.J., et al. Pulmonary impairment from chronic exposure to sulfur dioxide in a smelter. American Review of Respiratory Disease. Vol. 116 (1977). p. 31-39
(33) Emergency response planning guidelines. AIHA Journal. Vol. 56, no. 3, 1995. p. 297
(34) Safety Equipment Institute. Certified Product List, May 1996. SEI, Arlington, Virginia, USA
(35) European Communities (EC). Commission Directive 2001/59/EC. Aug. 6, 2001

Information on chemicals reviewed in the CHEMINFO database is drawn from a number of publicly available sources. A list of general references used to compile CHEMINFO records is available in the database Help.


Review/Preparation Date: 1993-11-09

Revision Indicators:
EU number 1996-06-01
Sampling 1996-06-01
Respiratory guidelines 1996-06-01
TLV-TWA 1996-09-01
TLV comments 1996-09-01
US transport 1998-03-01
Resistance of materials 1998-05-01
EU classification 2002-02-11
EU Safety 1998-11-01
EU comments 2002-02-11
EU risks 2002-02-11
TDG 2002-05-27
WHMIS detailed classification 2002-06-07
WHMIS proposed classification 2002-06-07
WHMIS health effects 2002-06-07
Corrosivity to metals 2002-06-12
Emergency overview 2002-06-12
First aid eye 2002-06-12
Handling 2002-06-14
Storage 2002-06-14
US transport 2002-12-04
Carcinogenicity 2002-12-23
WHMIS classification comments 2003-05-13
Important New Information 2003-05-13
Chemical Name French 2003-05-13
Short-term inhalation 2003-06-02
Short-term skin contact 2003-06-02
PEL-TWA final 2003-10-30
PEL-STEL final 2003-10-30
PEL final comments 2003-10-30
PEL transitional comments 2003-10-30
Resistance of materials for PPE 2004-03-28
Bibliography 2006-01-18
Vapour pressure at 50 deg C 2006-01-18
Relative density 2006-09-28
TLV-TWA 2007-03-06
TLV proposed changes 2007-03-06



©2007 Canadian  Centre  for  Occupational  Health  &  Safety  
www.ccohs.ca  E-mail: clientservices@ccohs.ca  Fax: (905) 572-2206  Phone: (905) 572-2981  
Mail:  250  Main  Street  East,  Hamilton  Ontario  L8N  1H6