International Chemical Safety Cards HAFNIUM POWDER ICSC: 0847 Hf Atomic mass: 178.5 (powder) ICSC #    0847 CAS #     7440-58-6 RTECS # MG4600000 UN #        2545 (powder, dry); 1326 (powder, wetted with water) October 26, 1995 Peer reviewed TYPES OF HAZARD/ EXPOSURE ACUTE HAZARDS/ SYMPTOMS PREVENTION FIRST AID/ FIRE FIGHTING FIRE Flammable. NO open flames, NO sparks, and NO smoking. Special powder. EXPLOSION Finely dispersed particles form explosive mixtures in air. Risk of fire and explosion (see Chemical Dangers). Do NOT expose to friction or shock. Prevent deposition of dust; closed system, dust explosion-proof electrical equipment and lighting. EXPOSURE PREVENT DISPERSION OF DUST!  •INHALATION Avoid inhalation of fine dust and mist. Local exhaust or breathing protection.  •SKIN Protective gloves. Remove contaminated clothes. Rinse and then wash skin with water and soap.  •EYES Redness. Safety spectacles.  •INGESTION Do not eat, drink, or smoke during work. Wash hands before eating. SPILLAGE DISPOSAL STORAGE PACKAGING & LABELLING Evacuate danger area! Consult an expert! Remove all ignition sources. Do NOT wash away into sewer. Do NOT absorb in saw-dust or other combustible absorbents. Wet powder to prevent dusting and ignition, then carefully collect powder into sealable containers. Remove to a safe place. (Extra personal protection: P2 filter respirator for harmful particles). Fireproof. Separated from strong oxidants, strong bases, halogens, phosphorous and sulfur. Keep under water. R: S: UN Hazard Class: 4.2 (dry); 4.1 (wetted) SEE IMPORTANT INFORMATION ON BACK ICSC: 0847 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 HAFNIUM POWDER ICSC: 0847 I M P O R T A N T D A T A PHYSICAL STATE; APPEARANCE: GREY POWDER. PHYSICAL DANGERS: Dust explosion possible if in powder or granular form, mixed with air. CHEMICAL DANGERS: May explosively decompose on shock, friction, or concussion. May explode on heating. The substance may spontaneously ignite on contact with air and at higher temperatures with nitrogen, phosphorous and sulphur. Reacts violently with strong acids, strong oxidants, halogens causing explosion hazard. OCCUPATIONAL EXPOSURE LIMITS: TLV: 0.5 mg/m3 (as TWA) (ACGIH 1995-1996). OSHA PEL*: TWA 0.5 mg/m3 *Note: The PEL also applies to other hafnium compounds (as Hf). NIOSH REL: TWA 0.5 mg/m3 *Note: The REL also applies to other hafnium compounds (as Hf). NIOSH IDLH: 50 mg/m3 (as Hf) ROUTES OF EXPOSURE: The substance can be absorbed into the body by inhalation of its aerosol. 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: Lungs may be affected by repeated or prolonged exposure. The substance may have effects on the liver. PHYSICAL PROPERTIES Boiling point: 4602°C Melting point: 2227°C Relative density (water = 1): 13.31 Solubility in water: none ENVIRONMENTAL DATA N O T E S Powder is normally handled wetted with no less than 25% of water to reduce the fire and explosion risk. Health effects of exposure to the substance have not been investigated adequately. Rinse contaminated clothes (fire hazard) with plenty of water. Transport Emergency Card: TEC (R)-41G13 ADDITIONAL INFORMATION ICSC: 0847 HAFNIUM POWDER (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.