NIOSH logo and tagline

Calcium sulfate

Synonyms & Trade Names
Anhydrous calcium sulfate, Anhydrous gypsum, Anhydrous sulfate of lime, Calcium salt of sulfuric acid [Note: Gypsum is the dihydrate form and Plaster of Paris is the hemihydrate form.]
CAS No.
7778-18-9
RTECS No.
DOT ID & Guide
Formula
CaSO₄
Conversion
IDLH
N.D.
See: IDLH INDEX
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)
Measurement Methods
NIOSH 0500 , 0600
See: NMAM or OSHA Methods
Physical Description
Odorless, white powder or colorless, crystalline solid. [Note: May have blue, gray, or reddish tinge.]
Molecular Weight
136.1
Boiling Point
Decomposes
Melting Point
2840°F (Decomposes)
Solubility
0.3%
Vapor Pressure
0 mmHg (approx)
Ionization Potential
NA
Specific Gravity
2.96
Flash Point
NA
Upper Explosive Limit
NA
Lower Explosive Limit
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.]
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
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
Skin:Soap wash
Breathing:Fresh air
Respirator Recommendations
See also
INTRODUCTION   ICSC CARD: 1589
Page last reviewed: October 30, 2019