NIOSH Publication No. 2005-151:

NIOSH Pocket Guide to Chemical Hazards

September 2005

Calcium sulfate

CAS
7778-18-9

CaSO4

RTECS
WS6920000
Synonyms & Trade Names

Anhydrous calcium sulfate, Anhydrous gypsum, Anhydrous sulfate of lime, Calcium salt of sulfuric acid [Note: Gypsum is the dihydrate form & Plaster of Paris is the hemihydrate form.]
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
Odorless, white powder or colorless, crystalline solid. [Note: May have blue, gray, or reddish tinge.]
MW: 136.1
BP: Decomposes
MLT: 2840°F (Decomposes)
Sol: 0.3%
VP: 0 mmHg (approx)
IP: NA

Sp.Gr: 2.96
Fl.P: NA
UEL: NA
LEL: NA

Noncombustible Solid
Incompatibilities & Reactivities

Diazomethane, aluminum, phosphorus, water [Note: Hygroscopic (i.e., absorbs moisture from the air). Reacts with water to form Gypsum & Plaster of Paris.]
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
Skin: Soap wash
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, upper respiratory system; conjunctivitis; rhinitis, epistaxis (nosebleed)
Target Organs
Eyes, skin, respiratory system
See also: INTRODUCTION