IPCS INCHEM Home
PLASTER OF PARIS
ICSC: 1217
Peer-Review Status: 26.10.2004 Validated
Gypsum hemihydrate 
CAS #: 26499-65-0 RTECS #: TP0700000
    Formula: (CaSO4)2.H2O
Molecular mass: 290.3

TYPES OF
HAZARD /
EXPOSURE
ACUTE HAZARDS / SYMPTOMS      PREVENTION      FIRST AID / FIRE FIGHTING
FIRE Not combustible.    In case of fire in the surroundings, use appropriate extinguishing media. 
EXPLOSION      
 
EXPOSURE      
Inhalation Cough.  Use local exhaust or breathing protection.  Fresh air, rest. 
Skin   Protective gloves.  Rinse and then wash skin with water and soap. 
Eyes Redness. Pain.  Wear safety spectacles.  First rinse with plenty of water for several minutes (remove contact lenses if easily possible), then refer for medical attention. 
Ingestion   Do not eat, drink, or smoke during work.  Rinse mouth. 

SPILLAGE DISPOSAL
PACKAGING & LABELLING
Personal protection: particulate filter respirator adapted to the airborne concentration of the substance. Sweep spilled substance into covered containers. If appropriate, moisten first to prevent dusting.   
EC Classification
 
UN Classification
 
GHS Classification
 

EMERGENCY RESPONSE SAFE STORAGE
  Dry. Well closed. 

IMPORTANT DATA
Physical State; Appearance
FINE HYGROSCOPIC WHITE POWDER. 

Physical dangers
 

Chemical dangers
 

Occupational exposure limits
TLV: 10mg/m³ as TWA; (ACGIH 2004). 

Routes of exposure
 

Inhalation risk
A nuisance-causing concentration of airborne particles can be reached quickly when dispersed, especially if powdered. 

Effects of short-term exposure
May cause mechanical irritation. 

Effects of long-term or repeated exposure
 


PHYSICAL PROPERTIES ENVIRONMENTAL DATA
Melting point: 163°C
Density (for the alpha hemihydrate): 2.76 g/cm³
Density (for the beta hemihydrate): 2.63 g/cm³
Solubility in water, g/100ml at 25°C: 0.30  
 

NOTES
Other CAS number is 10034-76-1.
The apparent melting point caused by loss of crystal water is given.
Melting point for the anhydrous form is 1450°C. 

ADDITIONAL INFORMATION
 

IPCS
International
Programme on
Chemical Safety
WHO ILO EC Prepared in the context of cooperation between the International Programme on Chemical Safety and the European Commission
© IPCS 2004-2012
LEGAL NOTICE Neither the EC nor the IPCS nor any person acting on behalf of the EC or the IPCS is responsible for the use which might be made of this information.


    See Also:
       Toxicological Abbreviations