# NIOSH Pocket Guide to Chemical Hazards
Sodium bisulfite | CAS 7631-90-5
NaHSO3 | RTECS VZ2000000
Synonyms & Trade Names Monosodium salt of sulfurous acid, Sodium acid bisulfite, Sodium bisulphite, Sodium hydrogen sulfite | DOT ID & Guide 2693 154 (solution)
Exposure Limits | NIOSH REL: TWA 5 mg/m3
OSHA PEL†: none
IDLH N.D. | Conversion
Physical Description White crystals or powder with a slight odor of sulfur dioxide.
MW: 104.1 | BP: Decomposes | MLT: Decomposes | Sol: 29%
VP: ? | IP: NA |  | Sp.Gr: 1.48
Fl.P: NA | UEL: NA | LEL: NA |
Noncombustible Solid
Incompatibilities & Reactivities Heat (decomposes) [Note: Slowly oxidized to the sulfate on exposure to air.]
Measurement Methods NIOSH 0500
Personal Protection & Sanitation 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 To be added later
Exposure Routes inhalation, ingestion, skin and/or eye contact
Symptoms Irritation eyes, skin, mucous membrane
Target Organs Eyes, skin, respiratory system
See also: INTRODUCTION