Sodium metabisulfite

  • Disodium pyrosulfite
  • Sodium pyrosulfite
  • Disodium disulfite
Formula
Na2O5S2
Structure
Description
White to yellowish crystals or powder with an odor of sulfur dioxide.
Uses
Pharmaceutic aid (antioxidant).

Registry Numbers and Inventories.
CAS
7681-57-4
EC (EINECS/ELINCS)
231-673-0
EC Index Number
016-063-00-2
EC Class
Harmful; Irritant; Contact with acids liberates toxic gas
R 22 31 41
S 26 39 46
RTECS
UX8225000
RTECS class
Agricultural Chemical and Pesticide; Tumorigen; Mutagen; Reproductive Effector; Primary Irritant
UN (DOT)
1759
Merck
12,8784
Beilstein/Gmelin
88460 (G)
EPA OPP
111409
Swiss Giftliste 1
G-2598
Canada DSL/NDSL
DSL
US TSCA
Listed
Austrailia AICS
Listed
New Zealand
Listed
Japan ENCS (MITI)
Listed
Korea ECL
Listed

Properties.
Formula
Na2O5S2
Formula mass
190.10
Melting point, °C
150
Density
1.48 g/cm3
Solubility in water
540 g/L

Hazards and Protection.
Storage
Store in a tightly closed container. Store in a cool, dry, well-ventilated area away from incompatible substances. Keep away from strong acids.
Handling
Wash thoroughly after handling. Minimize dust generation and accumulation. Avoid contact with eyes, skin, and clothing. Keep container tightly closed. Avoid ingestion and inhalation.
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
Clean up spills immediately, using the appropriate protective equipment. Sweep up, then place into a suitable container for disposal. Avoid generating dusty conditions. Provide ventilation. Do not get water inside containers.
Stability
Stable under normal shipping and handling conditions. However, may decompose if heated.
Incompatibilities
Strong oxidizers. Substance may produce sulfur dioxide gas when in contact with acids and/or water (ice).
Decomposition
Oxides of sulfur, toxic fumes of sodium oxide.

Fire.
Fire fighting
Wear a self-contained breathing apparatus in pressure-demand, MSHA/NIOSH (approved or equivalent), and full protective gear. During a fire, irritating and highly toxic gases may be generated by thermal decomposition or combustion. To extinguish fire, use water fog, dry chemical, carbon dioxide, or regular foam.
Fire potential
Non-combustible, substance itself does not burn but may decompose upon heating to produce corrosive and/or toxic fumes.
Hazards
Contact with metals may evolve flammable hydrogen gas.
Combustion products
Fire may produce irritating, corrosive and/or toxic gases.
Health
2
 
Flammability
0
 
 
Reactivity
0
 

Health.
Exposure limit(s)
NIOSH REL: TWA 5 mg/m3
Poison_Class
3
Exposure effects
Prolonged or repeated skin contact may cause dermatitis. Reproductive effects have been reported in animals. Repeated or prolonged exposure may cause allergic reactions in sensitive individuals.
   Ingestion
May cause gastrointestinal irritation with nausea, vomiting and diarrhea. May be harmful if swallowed. Exposure may cause central nervous system depression, gastrointestinal and cardiac abnormalities, and violent colic. Sulfite compounds may cause a severe allergic reaction in sensitive individuals and some asthmatics.
   Inhalation
May cause allergic respiratory reaction. May cause effects similar to those described for ingestion. Inhalation of dust may cause respiratory tract irritation.
   Skin
May cause skin irritation. May cause skin sensitization, an allergic reaction, which becomes evident upon re-exposure to this material.
   Eyes
May cause eye irritation.

First aid
 
   Ingestion
Do NOT induce vomiting. If victim is conscious and alert, give 2-4 cupfuls of milk or water. Get medical aid immediately.
   Inhalation
Remove from exposure to fresh air immediately. If not breathing, give artificial respiration. If breathing is difficult, give oxygen. Get medical aid. DO NOT use mouth-to-mouth respiration. If breathing has ceased apply artificial respiration using oxygen and a suitable mechanical device such as a bag and a mask.
   Skin
Get medical aid. Immediately flush skin with plenty of soap and water for at least 15 minutes while removing contaminated clothing and shoes. Wash clothing before reuse.
   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
1759
Response guide
Hazard class
8
Packing Group
I; II; III
 
HS Code
2832 10 00
 
Std. Transport #
4936350