Sulfurous acid

  • Sulfur dioxide solution
Formula
H2O3S
Structure
Description
Clear, colorless solution with a sulforous odor.
Uses
Dental bleach.

Registry Numbers and Inventories.
CAS
7782-99-2
EC (EINECS/ELINCS)
231-973-1
RTECS
WT2775000
RTECS class
Human Data
UN (DOT)
1833
Merck
12,9149
Beilstein/Gmelin
1458 (G)
Swiss Giftliste 1
G-1020
Canada DSL/NDSL
DSL
US TSCA
Listed
Austrailia AICS
Listed
Japan ENCS (MITI)
Listed
Korea ECL
Listed

Properties.
Formula
H2O3S
Formula mass
82.07
Vapor density (air=1)
2.8
Density
1.03 g/cm3 (20 C)
Solubility in water
Very soluble
pKa/pKb
1.53 (pKa)

Hazards and Protection.
Storage
Store in a cool, dry place. Keep container closed when not in use.
Handling
Wash thoroughly after handling. Remove contaminated clothing and wash before reuse. Use with adequate ventilation. Do not get on skin or in eyes. Do not ingest or inhale. Discard contaminated shoes.
Protection
Eyes: Wear appropriate protective eyeglasses or chemical safety goggles as described by OSHA's eye and face protection regulations in 29 CFR 1910.133 or European Standard EN166. Skin: Wear appropriate protective gloves to prevent skin exposure. Clothing: Wear appropriate protective clothing to prevent skin exposure.
Respirators
Follow the OSHA respirator regulations found in 29CFR 1910.134 or European Standard EN 149. Always use a NIOSH or European Standard EN 149 approved respirator when necessary.
Small spills/leaks
Absorb spill with inert material, (e.g., dry sand or earth), then place into a chemical waste container. Flush spill area with water. Spill may be neutralized with lime.
Stability
Oxidizes when exposed to air.
Incompatibilities
Strong bases.
Decomposition
Sulfur oxides (SOx), including sulfur oxide and sulfur dioxide.

Fire.
Fire fighting
Wear a self-contained breathing apparatus in pressure-demand, MSHA/NIOSH (approved or equivalent), and full protective gear. Extinguishing media: Use extinguishing media most appropriate for the surrounding fire.
Fire potential
Nonflammable.
Hazards
Some are oxidizers and may ignite combustibles (wood, paper, oil, clothing, etc.). Contact with metals may evolve flammable hydrogen gas. Containers may explode when heated.
Combustion products
Non-combustible, substance itself does not burn but may decompose upon heating to produce corrosive and/or toxic fumes.
Health
3
 
Flammability
0
 
 
Reactivity
0
 

Health.
Poison_Class
4
Exposure effects
   Ingestion
May cause hemorrhaging of the digestive tract. May cause corrosion and permanent tissue destruction of the esophagus and digestive tract.
   Inhalation
May cause irritation of the respiratory tract with burning pain in the nose and throat, coughing, wheezing, shortness of breath and pulmonary edema.
   Skin
Contact with liquid is corrosive and causes severe burns and ulceration.
   Eyes
Contact with liquid is corrosive to the eyes and causes severe burns.

First aid
 
   Ingestion
Do NOT induce vomiting. If victim is conscious and alert, give 2-4 cupfuls of milk or water. Never give anything by mouth to an unconscious person. Get medical aid immediately.
   Inhalation
Get medical aid immediately. Remove from exposure to fresh air immediately. If not breathing, give artificial respiration. If breathing is difficult, give oxygen.
   Skin
Get medical aid immediately. Immediately flush skin with plenty of soap and water for at least 15 minutes while removing contaminated clothing and shoes.
   Eyes
Immediately flush eyes with plenty of water for at least 15 minutes, occasionally lifting the upper and lower eyelids. Get medical aid immediately.

Transport.
UN number
1833
Response guide
Hazard class
8
Packing Group
II
 
Std. Transport #
4930258