September 2010
NIOSH Publication Number 2010-168c

Sodium metabisulfite

Synonyms & Trade Names
Disodium pyrosulfite, Sodium metabisulphite, Sodium pyrosulfite
CAS No.
7681-57-4
RTECS No.
UX8225000
DOT ID & Guide
Formula
Na2S2O5
Conversion
IDLH
N.D.
See: IDLH INDEX
Exposure Limits
NIOSH REL
: TWA 5 mg/m3
OSHA PEL
†: none
Measurement Methods

NIOSH 0500
Physical Description
White to yellowish crystals or powder with an odor of sulfur dioxide.
MW:
190.1
BP:
Decomposes		 MLT: >302°F (Decomposes)
Sol:
54%
VP:
?
IP:
NA
Sp.Gr:
1.4
Fl.P:
NA
UEL:
NA
LEL:
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

Not available.

Important additional information about respirator selection

See also: INTRODUCTION   See ICSC CARD: 1461