Add to MyChemicals Print Friendly Page
Chemical Datasheet

SULFUR DIOXIDE

0
3 0
 
Chemical Identifiers | Hazards | Response Recommendations | Physical Properties | Regulatory Information | Alternate Chemical Names

Chemical Identifiers

UN/NA Number - The United Nations-North America number (also called UN number or DOT number). 4-digit number identifying an individual chemical or group of chemicals with similar characteristics. Required on shipping papers; often shown on placards or labels. This numbering system was developed by the U.S. Department of Transportation, and then became the UN standard system for classifying hazardous materials.

CAS Number - Chemical Abstracts Service registry number. Unique identification number assigned to this chemical by the American Chemical Society.

CHRIS Code - 3-letter code used by the U.S. Coast Guard to identify individual chemicals included in its CHRIS (Chemical Hazards Response Information System) manual.

DOT Hazard Label - U.S. Department of Transportation hazard warning label for the chemical (such as flammable liquid or corrosive). This label must be displayed on shipped packages, railroad tank cars, and tank trucks according to specifications described in 49 CFR 172.

NFPA 704 - Text description of the diamond-shaped placard, which contains codes indicating the level of the chemical's health, flammability, and reactivity hazards, along with special hazards such as water- and air-reactivity. (The NFPA 704 diamond is also shown at the top of the datasheet.) See a guide to the NFPA diamond.

General Description - Brief description of the chemical's general appearance, behavior, and hazardousness.

List of data sources.
UN/NA Number CAS Number CHRIS Code DOT Hazard Label
  • 7446-09-5
  • POISON GAS
  • CORROSIVE
NFPA 704:
  • Red 0 -- Flammability: Will not burn
  • Blue 3 -- Health Hazard: Extremely hazardous - use full protection
  • Yellow 0 -- Reactivity: Normally stable
General Description
A colorless gas with a choking or suffocating odor. Boiling point -10°C. Heavier than air. Very toxic by inhalation and may irritate the eyes and mucous membranes. Under prolonged exposure to fire or heat the containers may rupture violently and rocket. Used to manufacture chemicals, in paper pulping, in metal and food processing.

Rate of onset: Immediate & Delayed

Persistence: Minutes to hours

Odor threshold: 1 ppm

Source/use/other hazard: Disinfectant and preserving in breweries and food/canning; textile industry; batteries.

Hazards

Reactivity Alerts - Special alerts if the chemical is especially reactive (see list of reactivity alerts).

Air & Water Reactions - Special alerts if the chemical reacts with air, water, or moisture.

Fire Hazard - Description of the chemical's fire hazards (such as flammability, explosion risk, or byproducts that may evolve if the chemical is burned).

Health Hazard - Description of the chemical's health hazards (such as toxicity, flammability, or corrosivity).

Reactivity Profile - Description of the chemical's potential reactivity with other chemicals, air, and water. Also includes any other intrinsic reactive hazards (such as polymerizable or peroxidizable).

Reactive Groups - List of reactive groups that the chemical is assigned to, based on its known chemistry. Reactive groups are categories of chemicals that react in similar ways because their chemical structures are similar. Reactive groups are used to predict reactivity when you add a chemical to MyChemicals. Read more about reactive groups.

List of data sources.
Reactivity Alerts
Air & Water Reactions
Dissolves in water to form sulfurous acid, a corrosive liquid. Moist sulfur dioxide is very corrosive due to the slow formation of sulfuric acid [Handling Chemicals Safely 1980 p. 876].
Fire Hazard
Containers may explode in heat of fire or they may rupture and release irritating toxic sulfur dioxide. Sulfur dioxide has explosive properties when it comes in contact with sodium hydride; potassium chlorate at elevated temperatures; ethanol; ether; zinc ethylsulfurinate at very cool temperatures (-15C); fluorine; chlorine trifluoride and chlorates. It will react with water or steam to produce toxic and corrosive fumes. When the liquid is heated it may release irritating, toxic sulfur dioxide gas. Avoid ammonia, monocesium or monopotassium acetylide; dicesium monoxide; iron (II) oxide; tin oxide; lead (IV) oxide; chromium; manganese; molten sodium, powder aluminum and rubidium. Sulfur dioxide has explosive properties when it comes in contact with sodium hydride; potassium chlorate at elevated temperatures; ethanol; ether; zinc ethylsulfurinate at very cool temperatures (-15C); fluorine; chlorine trifluoride and chlorates. It will react with water or steam to produce toxic and corrosive fumes. Hazardous polymerization may not occur. (EPA, 1998)
Health Hazard
It may cause death or permanent injury after very short exposure to small quantities. 1,000 ppm causes death in from 10 minutes to several hours by respiratory depression. It is an eye and respiratory tract irritant. Persons with asthma, subnormal pulmonary functions or cardiovascular disease are at a greater risk. (EPA, 1998)
Reactivity Profile
SULFUR DIOXIDE is acidic. Reacts exothermically with bases such as amines, amides, metal oxides, and hydroxides. Frequently used as a reducing agent although it is not a powerful one. Acts as a reducing bleach to decolorize many materials. Can act as an oxidizing agent. Supports combustion of powdered aluminum [Mellor 5:209-212 1946-47]. Reacts explosively with fluorine [Mellor 2:1 1946-47]. Supports burning of manganese [Mellor 12:187 1946-47]. Readily liquefied by compression. Contact between the liquid and water may result in vigorous or violent boiling and extremely rapid vaporization. If the water is hot an explosion may occur. Pressures may build to dangerous levels if the liquid contacts water in a closed container [Handling Chemicals Safely 1980]. Supports incandescent combustion of monocesium acetylide, monopotassium acetylide, cesium oxide, iron(II) oxide, tin oxide, and lead oxide [Mellor]. Ethylene oxide and SO2 can react violently in pyridine solution with pressurization if ethylene oxide is in excess (Nolan, 1983, Case History 51).
Belongs to the Following Reactive Group(s)

Response Recommendations

Firefighting - Response recommendations if the chemical is on fire (or near a fire).

Non-Fire Response - Response recommendations if the chemical isn't on fire (or near a fire).

Protective Clothing - Recommendations for protective gear and, in some cases, a table of breakthrough times for protective materials.

First Aid - Recommended first aid treatment for people exposed to the chemical.

List of data sources.
Firefighting
Wear self-contained breathing apparatus and full protective clothing. Move container from fire area. Stay away from ends of tanks. Cool containers that are exposed to flames with water from the side until well after the fire is out. Isolate area until gas has dispersed. Keep unnecessary people away.

Not flammable. Extinguish fires with dry chemical, carbon dioxide, water spray, fog or foam. (EPA, 1998)
Non-Fire Response
Keep material out of water sources and sewers. Attempt to stop leak if without undue personnel hazard. Use water spray to knock-down vapors. Neutralize spilled material with crushed limestone, soda ash, or lime. Do not use water on material itself. (AAR, 2003)
Protective Clothing
Skin: Wear appropriate personal protective clothing to prevent skin from becoming frozen from contact with the liquid or from contact with vessels containing the liquid.

Eyes: Wear appropriate eye protection to prevent eye contact with the liquid that could result in burns or tissue damage from frostbite.

Wash skin: No recommendation is made specifying the need for washing the substance from the skin (either immediately or at the end of the work shift).

Remove: If chemical is in liquid form, work clothing that becomes wet or significantly contaminated should be removed and replaced.

Change: No recommendation is made specifying the need for the worker to change clothing after the work shift.

Provide: 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, 2003)
_____Dupont Average Standardized Breakthrough Times_____
(for SULFUR DIOXIDE)

Tychem® BR
     greater than 480 min.  (concentration:  95+%)
Tychem® CPF2
     greater than 480 min.  (concentration:  95+%)
Tychem® CPF4
     greater than 480 min.  (concentration:  95+%)
Tychem® F
     38 min.  (concentration:  95+%)
Tychem® LV
     greater than 480 min.  (concentration:  95+%)
Tychem® QC
     immediate (less than 10 min.)  (concentration:  95+%)
Tychem® QC for Corrections
     immediate (less than 10 min.)  (concentration:  95+%)
Tychem® Reflector®
     greater than 480 min.  (concentration:  95+%)
Tychem® Responder®
     greater than 480 min.  (concentration:  99%)
Tychem® Responder® CSM
     greater than 480 min.  (concentration:  99%)
Tychem® SL
     greater than 480 min.  (concentration:  95+%)
Tychem® ThermoPro
     38* min.  (concentration:  100%)
Tychem® TK
     greater than 480 min.  (concentration:  95+%)  (DuPont, 2008)
Copyrighted information of E.I. du Pont de Nemours and Company. Tychem® is a registered trademark of E.I. du Pont de Nemours and Company.
First Aid
Note: Persons with asthma, subnormal pulmonary function, or cardiovascular disease are at greater risk.

Signs and Symptoms of Acute Sulfur Dioxide Exposure: Sulfur dioxide may irritate the eyes and respiratory tract. Signs and symptoms of acute exposure to sulfur dioxide may be severe and include coughing, choking, dyspnea (shortness of breath), sneezing, wheezing, and chest discomfort. Upper airway edema (swelling) or obstruction, bronchoconstriction, pneumonia, pulmonary edema, and respiratory paralysis may occur. Fatigue may be noted. Gastrointestinal effects may include nausea, vomiting, and abdominal pain. Cyanosis (blue tint to skin and mucous membranes) may be noted following exposure to sulfur dioxide.

Emergency Life-Support Procedures: Acute exposure to sulfur dioxide may require decontamination and life support for the victims. Emergency personnel should wear protective clothing appropriate to the type and degree of contamination. Air-purifying or supplied-air respiratory equipment should also be worn, as necessary. Rescue vehicles should carry supplies such as plastic sheeting and disposable plastic bags to assist in preventing spread of contamination.

Inhalation Exposure:
1. Move victims to fresh air. Emergency personnel should avoid self-exposure to sulfur dioxide.
2. Evaluate vital signs including pulse and respiratory rate, and note any trauma. If no pulse is detected, provide CPR. If not breathing, provide artificial respiration. If breathing is labored, administer oxygen or other respiratory support.
3. Obtain authorization and/or further instructions from the local hospital for administration of an antidote or performance of other invasive procedures.
4. Transport to a health care facility.

Dermal/Eye Exposure:
1. Remove victims from exposure. Emergency personnel should avoid self- exposure to sulfur dioxide.
2. Evaluate vital signs including pulse and respiratory rate, and note any trauma. If no pulse is detected, provide CPR. If not breathing, provide artificial respiration. If breathing is labored, administer oxygen or other respiratory support.
3. Remove contaminated clothing as soon as possible.
4. If eye exposure has occurred, eyes must be flushed with lukewarm water for at least 15 minutes.
5. Wash exposed skin areas with soap and water.
6. Obtain authorization and/or further instructions from the local hospital for administration of an antidote or performance of other invasive procedures.
7. Transport to a health care facility.

Ingestion Exposure: No information is available. (EPA, 1998)

Physical Properties

This section contains physical properties, flammability limits, and toxic thresholds for this chemical (see definitions of each property). More property data is available for common chemicals.

Guide to toxic levels of concern (AEGLs, ERPGs, TEELs, and IDLH).

List of data sources.
Molecular Formula:
  • SO2
Flash Point: data unavailable
Lower Explosive Limit: data unavailable
Upper Explosive Limit: data unavailable
Autoignition Temperature: Not flammable (USCG, 1999)
Melting Point: -98.9 ° F (EPA, 1998)
Vapor Pressure: 2432.0 mm Hg at 68.0 ° F (EPA, 1998)
Vapor Density: 2.26 (EPA, 1998)
Specific Gravity: 1.434 (EPA, 1998)
Boiling Point: 14.0 ° F at 760 mm Hg (EPA, 1998)
Molecular Weight: 64.07 (EPA, 1998)
Water Solubility: 10.0 % (NIOSH, 2003)
AEGL: data unavailable
ERPG-1 ERPG-2 ERPG-3
0.3 ppm 3.0 ppm 15.0 ppm
(AIHA, 2008)
TEEL: data unavailable
IDLH: 100.0 ppm (NIOSH, 2003)

Regulatory Information

Regulatory Names - Names under which this chemical is regulated under several U.S. federal laws: CAA (Clean Air Act of 1990), CERCLA (Comprehensive Environmental Response, Compensation, and Liability Act of 1980, also known as Superfund), EPCRA (Emergency Planning and Community Right-to-Know Act, also known as SARA Title III), and RCRA (Resource Conservation and Recovery Act of 1976).

CAA RMP - Indicates whether this chemical is regulated under Section 112(r) of the Clean Air Act, which lists about 100 toxic, flammable, or explosive hazardous substances. (Section 112(r) mandates the Risk Management Plan regulations.) For listed chemicals, the Threshold Quantity (from 40 CFR 68) is also shown. Facilities that use more than the threshold quantity of a listed chemical in a process are subject to the CAA accidental release prevention provisions.

CERCLA - Indicates whether this chemical is listed as a hazardous substance under CERCLA. For listed chemicals, the Reportable Quantity (from 40 CFR 302) is also shown. Facilities that spill more than the reportable quantity of a listed chemical must report it to federal, state, and local governments.

EHS (EPCRA 302) - Indicates whether this chemical is listed as an Extremely Hazardous Substance under Section 302 of EPCRA. For listed chemicals, the Threshold Planning Quantity (from 40 CFR 355) is also shown. Facilities that store more than the threshold quantity of an EHS chemical must meet the reporting, community right-to-know, and emergency planning requirements of EPCRA.

TRI (EPCRA 313) - Indicates whether this chemical is listed as a toxic chemical under Section 313 (Toxics Release Inventory) of EPCRA. Facilities that manufacture, store, or use significant amounts of Section 313 chemicals may be required to submit annual reports about any releases into the environment (see 40 CFR 372).

RCRA Chemical Code - 4-character identification code assigned to this substance under RCRA.
Regulatory Names:
  • SULFUR DIOXIDE (ANHYDROUS)
  • SULFUR DIOXIDE
CAA RMP: Regulated chemical with a Threshold Quantity of 5000 pounds.
CERCLA: Not a regulated chemical.
EHS (EPCRA 302): Regulated chemical with a Reportable Quantity of 500 pounds and a Threshold Planning Quantity of 500 pounds.
TRI (EPCRA 313): Not a regulated chemical.
RCRA Chemical Code: none

Alternate Chemical Names

This section provides a listing of alternate names for this chemical, including trade names, synonyms, and foreign names.