International Chemical Safety Cards 2-METHYL-2-PROPANETHIOL ICSC: 0019 tert-Butyl mercaptan (CH3)3CSH / C4H10S Molecular mass: 90.2 ICSC #    0019 CAS #     75-66-1 RTECS # TZ7660000 UN #        2347 April 23, 2004 Peer reviewed TYPES OF HAZARD/ EXPOSURE ACUTE HAZARDS/ SYMPTOMS PREVENTION FIRST AID/ FIRE FIGHTING FIRE Highly flammable. NO open flames, NO sparks, and NO smoking. Foam, carbon dioxide, powder . EXPLOSION Vapour/air mixtures are explosive. Closed system, ventilation, explosion-proof electrical equipment and lighting. Do NOT use compressed air for filling, discharging, or handling. In case of fire: keep drums, etc., cool by spraying with water. EXPOSURE  •INHALATION Cough. Dizziness. Headache. Nausea. Drowsiness. Ventilation, local exhaust, or breathing protection. Fresh air, rest. Refer for medical attention.  •SKIN Protective gloves. Remove contaminated clothes. Rinse and then wash skin with water and soap.  •EYES Redness. Safety goggles, or eye protection in combination with breathing protection. First rinse with plenty of water for several minutes (remove contact lenses if easily possible), then take to a doctor.  •INGESTION Nausea. Vomiting. Do not eat, drink, or smoke during work. Rinse mouth. SPILLAGE DISPOSAL STORAGE PACKAGING & LABELLING Evacuate danger area! Remove all ignition sources. Collect leaking and spilled liquid in sealable containers as far as possible. Absorb remaining liquid in sand or inert absorbent and remove to safe place. Do NOT wash away into sewer. Carefully collect remainder, then remove to safe place. Personal protection: filter respirator for organic gases and vapours. Fireproof. Separated from strong oxidants, strong bases, strong acids, metals , strong reducing agents . R: S: UN Hazard Class: 3 UN Packing Group: II SEE IMPORTANT INFORMATION ON BACK ICSC: 0019 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 2-METHYL-2-PROPANETHIOL ICSC: 0019 I M P O R T A N T D A T A PHYSICAL STATE; APPEARANCE: COLOURLESS LIQUID , WITH CHARACTERISTIC ODOUR. PHYSICAL DANGERS: The vapour is heavier than air and may travel along the ground; distant ignition possible. CHEMICAL DANGERS: The substance decomposes on burning producing toxic gases including sulfur oxides . Reacts with strong acids , strong bases , metals , strong oxidants , strong reducing agents to produce sulfur oxides . OCCUPATIONAL EXPOSURE LIMITS: TLV not established. MAK not established. ROUTES OF EXPOSURE: The substance can be absorbed into the body by inhalation. INHALATION RISK: A harmful contamination of the air can be reached rather quickly on evaporation of this substance at 20°C. EFFECTS OF SHORT-TERM EXPOSURE: The substance is irritating to the eyes and the respiratory tract . Exposure at high levels may result in lowering of consciousness. EFFECTS OF LONG-TERM OR REPEATED EXPOSURE: PHYSICAL PROPERTIES Boiling point: 64°C Melting point: 0°C Relative density (water = 1): 0.80 Vapour pressure, kPa at 20°C: 19.0 Relative vapour density (air = 1): 3.1 Relative density of the vapour/air-mixture at 20°C (air = 1): 1.4 Flash point: -26°C c.c. ENVIRONMENTAL DATA N O T E S Auto-ignition temperature is unknown in literature. Explosive limits are unknown in literature, although the substance is combustible and has a flash point < 61°C. Health effects of exposure to the substance have not been investigated adequately. Transport Emergency Card: TEC (R)-30GFI-I+II ADDITIONAL INFORMATION ICSC: 0019 2-METHYL-2-PROPANETHIOL (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.