International Chemical Safety Cards TRIDYMITE ICSC: 0807 Crystalline silica, tridymite Crystalline silicon dioxide, tridymite SiO2 Molecular mass: 60.1 ICSC #    0807 CAS #     15468-32-3 RTECS # VV7335000 October 09, 1997 Peer reviewed TYPES OF HAZARD/ EXPOSURE ACUTE HAZARDS/ SYMPTOMS PREVENTION FIRST AID/ FIRE FIGHTING FIRE Not combustible. In case of fire in the surroundings: all extinguishing agents allowed. EXPLOSION EXPOSURE PREVENT DISPERSION OF DUST!  •INHALATION Cough. Local exhaust or breathing protection.  •SKIN  •EYES Safety goggles, or eye protection in combination with breathing protection.  •INGESTION SPILLAGE DISPOSAL STORAGE PACKAGING & LABELLING Sweep spilled substance into containers; if appropriate, moisten first to prevent dusting. Wash away remainder with plenty of water. (Extra personal protection: P3 filter respirator for toxic particles). R: S: SEE IMPORTANT INFORMATION ON BACK ICSC: 0807 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 TRIDYMITE ICSC: 0807 I M P O R T A N T D A T A PHYSICAL STATE; APPEARANCE: COLOURLESS OR WHITE CRYSTALS PHYSICAL DANGERS: CHEMICAL DANGERS: Reacts with strong oxidants causing fire and explosion hazard. OCCUPATIONAL EXPOSURE LIMITS: TLV: 0.05 mg/m3 (respirable dust) (ACGIH 1997). MAK: 0.15 mg/m3; (1996) ROUTES OF EXPOSURE: The substance can be absorbed into the body by inhalation. INHALATION RISK: Evaporation at 20°C is negligible; a harmful concentration of airborne particles can, however, be reached quickly when dispersed. EFFECTS OF SHORT-TERM EXPOSURE: EFFECTS OF LONG-TERM OR REPEATED EXPOSURE: The substance may have effects on the lungs , resulting in fibrosis (silicosis). This substance is possibly carcinogenic to humans. PHYSICAL PROPERTIES Boiling point: 2230°C Melting point: 1703°C Relative density (water = 1): 2.3 Solubility in water: none ENVIRONMENTAL DATA N O T E S Depending on the degree of exposure, periodic medical examination is indicated. ADDITIONAL INFORMATION ICSC: 0807 TRIDYMITE (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.