Plaster of Paris
Synonyms & Trade Names
Calcium sulfate hemihydrate, Dried calcium sulfate, Gypsum hemihydrate, Hemihydrate gypsum [Note: Plaster of Paris is the hemihydrate form of Calcium Sulfate & Gypsum is the dihydrate form.]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)Physical Description
White or yellowish, finely divided, odorless powder.Molecular Weight
145.2Boiling Point
?Melting Point
325°F (Loses H2O)Solubility
(77°F): 0.3%Vapor Pressure
0 mmHg (approx)Ionization Potential
NASpecific Gravity
2.5Flash Point
NAUpper Exposive Limit
NALower Explosive Limit
NA
Noncombustible Solid
Incompatibilities & Reactivities
Moisture, water [Note: Hygroscopic (i.e., absorbs moisture from the air). Reacts with water to form Gypsum.]Exposure Routes
inhalation, ingestion, skin and/or eye contactSymptoms
irritation eyes, skin, mucous membrane, respiratory system; coughTarget Organs
Eyes, skin, respiratory systemPersonal 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
Breathing:Respiratory support
Swallow:Medical attention immediately
Respirator Recommendations
Not available.
- Page last reviewed:April 11, 2016
- Page last updated:April 11, 2016
- Content source:
- National Institute for Occupational Safety and Health (NIOSH) Education and Information Division