NIOSH Publication No. 2005-151:

NIOSH Pocket Guide to Chemical Hazards

September 2005

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. See: IDLH INDEX
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
See: NMAM or OSHA Methods
Personal Protection & Sanitation
(See protection)
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
Not available.
Important additional information about respirator selection
Exposure Routes
inhalation, skin and/or eye contact
Symptoms
Irritation eyes, skin, respiratory system; cough
Target Organs
Eyes, skin, respiratory system
See also: INTRODUCTION   See ICSC CARD: 0969