# NIOSH Pocket Guide to Chemical Hazards
Magnesite | CAS 546-93-0
MgCO3 | RTECS OM2470000
Synonyms & Trade Names Carbonate magnesium, Hydromagnesite, Magnesium carbonate, Magnesium(II) carbonate [Note: Magnesite is a naturally-occurring form of magnesium carbonate.] | DOT ID & Guide
Exposure Limits | NIOSH REL: TWA 10 mg/m3 (total) TWA 5 mg/m3 (resp)
OSHA PEL: TWA 15 mg/m3 (total) TWA 5 mg/m3 (resp)
IDLH N.D. | Conversion
Physical Description White, odorless, crystalline powder.
MW: 84.3 | BP: Decomposes | MLT: 662°F (Decomposes) | Sol: 0.01%
VP: 0 mmHg (approx) | IP: NA |  | Sp.Gr: 2.96
Fl.P: NA | UEL: NA | LEL: NA |
Noncombustible Solid
Incompatibilities & Reactivities Acids, formaldehyde
Measurement Methods NIOSH 0500, 0600
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
Respirator Recommendations To be added later
Exposure Routes inhalation, skin and/or eye contact
Symptoms Irritation eyes, skin, respiratory system; cough
Target Organs Eyes, skin, respiratory system
See also: INTRODUCTION