Chemical Datasheet
SULFUR DIOXIDE |
|
Chemical Identifiers
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| CAS Number | UN/NA Number | DOT Hazard Label | USCG CHRIS Code |
|---|---|---|---|
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|
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| NIOSH Pocket Guide | International Chem Safety Card | ||
Sulfur dioxide
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NFPA 704
| Diamond | Hazard | Value | Description | |||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
|
Health
|
3 | Can cause serious or permanent injury. | |||||||||
Flammability
|
0 | Will not burn under typical fire conditions. | ||||||||||
Instability
|
0 | Normally stable, even under fire conditions. | ||||||||||
Special
|
(NFPA, 2010)
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.
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
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Hazard fields
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special hazard alerts
air and water
reactions, fire hazards, health hazards, a reactivity profile, and
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reactive groups assignments
and
potentially incompatible absorbents.
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Reactivity Alerts
- Water-Reactive
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)
Potentially Incompatible Absorbents
No information available.
Response Recommendations
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Response Recommendation fields
include isolation and evacuation distances, as well as recommendations for
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Isolation and Evacuation
Excerpt from ERG Guide 125 [Gases - Toxic and/or Corrosive]:
IMMEDIATE PRECAUTIONARY MEASURE: Isolate spill or leak area for at least 100 meters (330 feet) in all directions.
SPILL: See ERG Tables 1 and 3 - Initial Isolation and Protective Action Distances on the UN/NA 1079 datasheet.
FIRE: If tank, rail tank car or highway tank is involved in a fire, ISOLATE for 1600 meters (1 mile) in all directions; also, consider initial evacuation for 1600 meters (1 mile) in all directions. (ERG, 2024)
IMMEDIATE PRECAUTIONARY MEASURE: Isolate spill or leak area for at least 100 meters (330 feet) in all directions.
SPILL: See ERG Tables 1 and 3 - Initial Isolation and Protective Action Distances on the UN/NA 1079 datasheet.
FIRE: If tank, rail tank car or highway tank is involved in a fire, ISOLATE for 1600 meters (1 mile) in all directions; also, consider initial evacuation for 1600 meters (1 mile) in all directions. (ERG, 2024)
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)
Not flammable. Extinguish fires with dry chemical, carbon dioxide, water spray, fog or foam. (EPA, 1998)
Non-Fire Response
Excerpt from ERG Guide 125 [Gases - Toxic and/or Corrosive]:
Do not touch or walk through spilled material. Stop leak if you can do it without risk. If possible, turn leaking containers so that gas escapes rather than liquid. Prevent entry into waterways, sewers, basements or confined areas. Do not direct water at spill or source of leak. Use water spray to reduce vapors or divert vapor cloud drift. Avoid allowing water runoff to contact spilled material. Isolate area until gas has dispersed. (ERG, 2024)
Do not touch or walk through spilled material. Stop leak if you can do it without risk. If possible, turn leaking containers so that gas escapes rather than liquid. Prevent entry into waterways, sewers, basements or confined areas. Do not direct water at spill or source of leak. Use water spray to reduce vapors or divert vapor cloud drift. Avoid allowing water runoff to contact spilled material. Isolate area until gas has dispersed. (ERG, 2024)
Protective Clothing
Excerpt from NIOSH Pocket Guide for Sulfur dioxide:
Skin: FROSTBITE - Compressed gases may create low temperatures when they expand rapidly. Leaks and uses that allow rapid expansion may cause a frostbite hazard. Wear appropriate personal protective clothing to prevent the skin from becoming frozen.
Eyes: FROSTBITE - 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: WHEN WET OR CONTAMINATED (LIQUID) - If this 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 workshift.
Provide: FROSTBITE WASH - 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, 2024)
:Skin: FROSTBITE - Compressed gases may create low temperatures when they expand rapidly. Leaks and uses that allow rapid expansion may cause a frostbite hazard. Wear appropriate personal protective clothing to prevent the skin from becoming frozen.
Eyes: FROSTBITE - 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: WHEN WET OR CONTAMINATED (LIQUID) - If this 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 workshift.
Provide: FROSTBITE WASH - 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, 2024)
DuPont Tychem® Suit Fabrics
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Tychem® Fabric Legend
| QS = Tychem 2000 SFR |
| QC = Tychem 2000 |
| SL = Tychem 4000 |
| C3 = Tychem 5000 |
| TF = Tychem 6000 |
| TP = Tychem 6000 FR |
| RC = Tychem RESPONDER® CSM |
| TK = Tychem 10000 |
| RF = Tychem 10000 FR |
Testing Details
The fabric permeation data was generated for DuPont by a third party
laboratory. Permeation data for industrial chemicals is obtained per
ASTM F739. Normalized breakthrough times (the time at which the
permeation rate exceeds 0.1 μg/cm2/min) are reported in minutes. All
chemicals have been tested between approximately 20°C and 27°C unless
otherwise stated. All chemicals have been tested at a concentration of
greater than 95% unless otherwise stated.
Chemical warfare agents (Lewisite, Sarin, Soman, Sulfur Mustard, Tabun
and VX Nerve Agent) have been tested at 22°C and 50% relative humidity
per military standard MIL-STD-282. "Breakthrough time" for chemical
warfare agents is defined as the time when the cumulative mass which
permeated through the fabric exceeds the limit in MIL-STD-282 [either
1.25 or 4.0 μg/cm2].
A Caution from DuPont
This information is based upon technical data that DuPont believes to
be reliable on the date issued. It is subject to revision as additional
knowledge and experience are gained. The information reflects
laboratory performance of fabrics, not complete garments, under
controlled conditions. It is intended for informational use by persons
having technical skill for evaluation under their specific end-use
conditions, at their own discretion and risk. It is the user's
responsibility to determine the level of toxicity and the proper
personal protective equipment needed. Anyone intending to use this
information should first verify that the garment selected is suitable
for the intended use. In many cases, seams and closures have shorter
breakthrough times and higher permeation rates than the fabric. If
fabric becomes torn,abraded or punctured, or if seams or closures fail,
or if attached gloves, visors, etc. are damaged, end user should
discontinue use of garment to avoid potential exposure to chemical.
Since conditions of use are outside our control, DuPont makes no
warranties, express or implied, including, without limitation, no
warranties of merchantability or fitness for a particular use and
assume no liability in connection with any use of this information.
This information is not intended as a license to operate under or a
recommendation to infringe any patent, trademark or technical
information of DuPont or others covering any material or its use.
| Chemical | CAS Number | State | QS | QC | SL | C3 | TF | TP | RC | TK | RF |
|---|---|---|---|---|---|---|---|---|---|---|---|
| Sulfur dioxide | 7446-09-5 | Vapor | imm | >480 | 28*/46 | 26*/37 | >480 | >480 | >480 |
> indicates greater than.
"imm" indicates immediate; having a normalized breakthrough time of 10 minutes or less.
* indicates based on lowest single value.
"imm" indicates immediate; having a normalized breakthrough time of 10 minutes or less.
* indicates based on lowest single value.
Special Warning from DuPont: Tychem® and Tyvek® fabrics should not be used around heat, flames, sparks or in potentially flammable or explosive environments. Only...
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...Tychem® ThermoPro, Tychem® Reflector® and Tychem® TK styles 600T/601T
(with aluminized outer suit) garments are designed and tested to help
reduce burn injury during escape from a flash fire. Users of Tychem®
ThermoPro, Tychem® Reflector® and Tychem® TK styles 600T/601T (with
aluminized outer suit) garments should not knowingly enter an explosive
environment. Tychem® garments with attached socks must be worn inside
protective outer footwear and are not suitable as outer footwear. These
attached socks do not have adequate durability or slip resistance to be
worn as the outer foot covering.
(DuPont, 2024)
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)
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
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The
Physical Property fields
include properties such as vapor pressure and
boiling point, as well as explosive limits and
toxic exposure thresholds
The information in CAMEO Chemicals comes from a variety of
data sources.
Note: For Vapor Density and Specific Gravity, comparing the value to 1.0 can tell you if the chemical will likely sink/rise in air or sink/float in fresh water (respectively). Short phrases have been added to those values below as an aid. However, make sure to also consider the circumstances of a release. The Vapor Density comparisons are only valid when the gas escaping is at the same temperature as the surrounding air itself. If the chemical is escaping from a container where it was pressurized or refrigerated, it may first escape and behave as a heavy gas and sink in the air (even if it has a Vapor Density value less than 1). Also, the Specific Gravity comparisons are for fresh water (density 1.0 g/mL). If your spill is in salt water (density about 1.027 g/mL), you need to adjust the point of comparison. There are some chemicals that will sink in fresh water and float in salt water.
Note: For Vapor Density and Specific Gravity, comparing the value to 1.0 can tell you if the chemical will likely sink/rise in air or sink/float in fresh water (respectively). Short phrases have been added to those values below as an aid. However, make sure to also consider the circumstances of a release. The Vapor Density comparisons are only valid when the gas escaping is at the same temperature as the surrounding air itself. If the chemical is escaping from a container where it was pressurized or refrigerated, it may first escape and behave as a heavy gas and sink in the air (even if it has a Vapor Density value less than 1). Also, the Specific Gravity comparisons are for fresh water (density 1.0 g/mL). If your spill is in salt water (density about 1.027 g/mL), you need to adjust the point of comparison. There are some chemicals that will sink in fresh water and float in salt water.
| Chemical Formula: |
|
Flash Point: data unavailable
Lower Explosive Limit (LEL): data unavailable
Upper Explosive Limit (UEL): data unavailable
Autoignition Temperature:
Not flammable
(USCG, 1999)
Melting Point:
-98.9°F
(EPA, 1998)
Vapor Pressure:
2432 mmHg
at 68°F
(EPA, 1998)
Vapor Density (Relative to Air):
2.26
(EPA, 1998)
- Heavier than air; will sink
Specific Gravity:
1.434
(EPA, 1998)
- Denser than water; will sink
Boiling Point:
14°F
at 760 mmHg
(EPA, 1998)
Molecular Weight:
64.07
(EPA, 1998)
Water Solubility:
10 %
(NIOSH, 2024)
Ionization Energy/Potential:
12.30 eV
(NIOSH, 2024)
IDLH:
100 ppm
(NIOSH, 2024)
AEGLs (Acute Exposure Guideline Levels)
| Exposure Period | AEGL-1 | AEGL-2 | AEGL-3 |
|---|---|---|---|
| 10 minutes | 0.2 ppm | 0.75 ppm | 30 ppm |
| 30 minutes | 0.2 ppm | 0.75 ppm | 30 ppm |
| 60 minutes | 0.2 ppm | 0.75 ppm | 30 ppm |
| 4 hours | 0.2 ppm | 0.75 ppm | 19 ppm |
| 8 hours | 0.2 ppm | 0.75 ppm | 9.6 ppm |
(NAC/NRC, 2024)
ERPGs (Emergency Response Planning Guidelines)
| Chemical | ERPG-1 | ERPG-2 | ERPG-3 |
|---|---|---|---|
| Sulfur Dioxide (7446-09-5) | 0.3 ppm  |
3 ppm | 25 ppm |
indicates that odor should be detectable near ERPG-1.(AIHA, 2022)
PACs (Protective Action Criteria)
| Chemical | PAC-1 | PAC-2 | PAC-3 |
|---|---|---|---|
| Sulfur dioxide (7446-09-5) | 0.2 ppm | 0.75 ppm | 30 ppm |
(DOE, 2024)
Regulatory Information
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The
Regulatory Information fields
include information from
the U.S. Environmental Protection Agency's Title III Consolidated List of
Lists,
the U.S. Cybersecurity and Infrastructure Security Agency's Chemical Facility
Anti-Terrorism Standards,
and the U.S. Occupational Safety and Health Administration's
Process Safety Management of Highly Hazardous Chemicals Standard List
(see more about these
data sources).
EPA Consolidated List of Lists
| Regulatory Name | CAS Number/ 313 Category Code |
EPCRA 302 EHS TPQ |
EPCRA 304 EHS RQ |
CERCLA RQ | EPCRA 313 TRI |
RCRA Code |
CAA 112(r) RMP TQ |
|---|---|---|---|---|---|---|---|
| Sulfur dioxide | 7446-09-5 | 500 pounds | 500 pounds | ||||
| Sulfur dioxide (anhydrous) | 7446-09-5 | 500 pounds | 500 pounds | 5000 pounds |
(EPA List of Lists, 2024)
CISA Chemical Facility Anti-Terrorism Standards (CFATS)
| RELEASE | THEFT | SABOTAGE | ||||||||
|---|---|---|---|---|---|---|---|---|---|---|
| Chemical of Interest | CAS Number | Min Conc | STQ | Security Issue |
Min Conc | STQ | Security Issue |
Min Conc | STQ | Security Issue |
| Sulfur dioxide (anhydrous) | 7446-09-5 | 1.00 % | 5000 pounds | toxic | 84.00 % | 500 pounds | WME | |||
- WME = weapons of mass effect.
(CISA, 2007)
OSHA Process Safety Management (PSM) Standard List
| Chemical Name | CAS Number | Threshold Quantity (TQ) |
|---|---|---|
| Sulfur Dioxide (liquid) | 7446-09-5 | 1000 pounds |
(OSHA, 2019)
Alternate Chemical Names
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This section provides a listing of alternate names for this chemical,
including trade names and synonyms.
- FERMENTICIDE LIQUID
- SULFUR DIOXIDE
- SULFUR DIOXIDE (ANHYDROUS)
- SULFUR DIOXIDE (SO2)
- SULFUR DIOXIDE, LIQUEFIED
- SULFUR OXIDE
- SULFUR OXIDE (SO2)
- SULFUR SUPEROXIDE
- SULFUROUS ACID ANHYDRIDE
- SULFUROUS ANHYDRIDE
- SULFUROUS OXIDE
- SULPHUR DIOXIDE
- SULPHUR DIOXIDE, LIQUEFIED
Web site owner:
Office of Response and Restoration,
National Ocean Service,
National Oceanic and Atmospheric Administration.
USA.gov.
CAMEO Chemicals version 3.1.0 rev 1.