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PLASTER OF PARIS ICSC: 1217
October 2004
Gypsum hemihydrate PDF for printing Explanation of fields
CAS No: 26499-65-0
RTECS No: TP0700000
    (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. Local exhaust or breathing protection. Fresh air, rest.
Skin   Protective gloves. Rinse and then wash skin with water and soap.
Eyes Redness. Pain. Safety spectacles. First rinse with plenty of water for several minutes (remove contact lenses if easily possible), then take to a doctor.
Ingestion   Do not eat, drink, or smoke during work. Rinse mouth.

SPILLAGE DISPOSAL PACKAGING & LABELLING
Sweep spilled substance into containers; if appropriate, moisten first to prevent dusting. Personal protection: P1 filter respirator for inert particles.  

EMERGENCY RESPONSE SAFE STORAGE
  Dry. Well closed.

IMPORTANT DATA
Physical State; Appearance
FINE HYGROSCOPIC WHITE POWDER

Occupational exposure limits
TLV: (as total dust containing no asbestos and <1 % crystalline silica) 10 mg/m³ as TWA; (ACGIH 2004).
MAK: (as respirable fraction of the aerosol, without fibers) 6 mg/m³; (DFG 2004).

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.


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

IPCS
International
Programme on
Chemical Safety
WHO ILO UNEP EC Prepared in the context of cooperation between the International Programme on Chemical Safety and the European Commission
© IPCS 2004
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.

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