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Plaster of Paris																				Related Pages
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.]
CAS No.
			26499-65-0
	RTECS No.
			TP0700000
	DOT ID & Guide

FormulaCaSO4 • 0.5H2O
	Conversion
	IDLH
			N.D.See: IDLH INDEX

Exposure Limits
			NIOSH RELTWA 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
			White or yellowish, finely divided, odorless powder.													
										
Molecular Weight145.2	
	Boiling Point?
	Melting Point325°F (Loses H2O)
	Solubility(77°F): 0.3%
	Vapor Pressure0 mmHg (approx)
	Ionization PotentialNA											
Specific Gravity2.5	
	Flash PointNA
	Upper Explosive LimitNA
	Lower Explosive LimitNA
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 contact
Symptoms
			irritation eyes, skin, mucous membrane, respiratory system; cough
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
							**Breathing:**Respiratory support
							**Swallow:**Medical attention immediately
Respirator Recommendations
			Not available.
				Important additional information about respirator selection
See also
			INTRODUCTION
					  ICSC CARD: 1217

			
							

			Page last reviewed:  October 30, 2019						Content
							source: 	National Institute for Occupational Safety and Health NIOSH Pocket Guide to Chemical Hazards
Introduction
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Chemical Names, Synonyms and Trade Names
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CAS Numbers
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Appendices
A – NIOSH Potential Occupational Carcinogens
B – Thirteen OSHA-Regulated Carcinogens
C – Supplementary Exposure Limits
D – Substances with No Established RELs
E – OSHA Respirator Requirements for Selected Chemicals
F – Miscellaneous Notes
G – 1989 Air Contaminants Update Project: Exposure Limits NOT in Effect
Type C & CE – Definitions for Type C and Type CE Respirators
Personal Protection and Sanitation Codes
First Aid Procedures Follow NIOSH Facebook
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