International Chemical Safety Cards PLASTER OF PARIS ICSC: 1217 Gypsum hemihydrate (CaSO4)2•H2O Molecular mass: 290.3 ICSC #    1217 CAS #     26499-65-0 RTECS # TP0700000 October 26, 2004 Peer reviewed 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 STORAGE PACKAGING & LABELLING Sweep spilled substance into containers; if appropriate, moisten first to prevent dusting. Personal protection: P1 filter respirator for inert particles. Dry. Well closed. R: S: SEE IMPORTANT INFORMATION ON BACK ICSC: 1217 Prepared in the context of cooperation between the International Programme on Chemical Safety & the Commission of the European Communities (C) IPCS CEC 1994. No modifications to the International version have been made except to add the OSHA PELs, NIOSH RELs and NIOSH IDLH values.

International Chemical Safety Cards PLASTER OF PARIS ICSC: 1217 I M P O R T A N T D A T A PHYSICAL STATE; APPEARANCE: FINE HYGROSCOPICWHITEPOWDER PHYSICAL DANGERS: CHEMICAL DANGERS: 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). OSHA PEL: TWA 15 mg/m3 (total) TWA 5 mg/m3 (resp) NIOSH REL: TWA 10 mg/m3 (total) TWA 5 mg/m3 (resp) NIOSH IDLH: No data 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 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 ENVIRONMENTAL DATA N O T E S 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 ICSC: 1217 PLASTER OF PARIS (C) IPCS, CEC, 1994

IMPORTANT LEGAL NOTICE: Neither NIOSH, the CEC or the IPCS nor any person acting on behalf of NIOSH, the CEC or the IPCS is responsible for the use which might be made of this information. This card contains the collective views of the IPCS Peer Review Committee and may not reflect in all cases all the detailed requirements included in national legislation on the subject. The user should verify compliance of the cards with the relevant legislation in the country of use. The only modifications made to produce the U.S. version is inclusion of the OSHA PELs, NIOSH RELs and NIOSH IDLH values.