NIOSH logo and tagline

Sodium metabisulfite

Synonyms & Trade Names
Disodium pyrosulfite, Sodium metabisulphite, Sodium pyrosulfite
CAS No.
7681-57-4
RTECS No.
DOT ID & Guide
Formula
Na₂S₂O₅
Conversion
IDLH
N.D.
See: IDLH INDEX
Exposure Limits
NIOSH REL
TWA 5 mg/m3
OSHA PEL
none See Appendix G
Measurement Methods
NIOSH 0500
See: NMAM or OSHA Methods
Physical Description
White to yellowish crystals or powder with an odor of sulfur dioxide.
Molecular Weight
190.1
Boiling Point
Decomposes
Melting Point
>302°F (Decomposes)
Solubility
54%
Vapor Pressure
?
Ionization Potential
NA
Specific Gravity
1.4
Flash Point
NA
Upper Explosive Limit
NA
Lower Explosive Limit
NA
Noncombustible Solid
Incompatibilities & Reactivities
Heat (decomposes) [Note: Slowly oxidized to the sulfate on exposure to air & moisture.]
Exposure Routes
inhalation, ingestion, skin and/or eye contact
Symptoms
irritation eyes, skin, mucous membrane
Target Organs
Eyes, skin, respiratory system
Personal Protection/Sanitation
(See protection codes)
Skin:No recommendation
Eyes:No recommendation
Wash skin:No recommendation
Remove:No recommendation
Change:No recommendation
First Aid
(See procedures)
Eye:Irrigate immediately

Breathing:Fresh air
Swallow:Medical attention immediately
Respirator Recommendations
See also
INTRODUCTION   ICSC CARD: 1461
Page last reviewed: October 30, 2019