International Chemical Safety Cards 1-HEXADECANETHIOL ICSC: 0025 Hexadecyl mercaptan 1-Mercaptohexadecane Cetyl mercaptan Hexadecane-1-thiol CH3(CH2)15SH / C16H34S Molecular mass: 258.5 ICSC #    0025 CAS #     2917-26-2 RTECS # April 23, 2004 Peer reviewed TYPES OF HAZARD/ EXPOSURE ACUTE HAZARDS/ SYMPTOMS PREVENTION FIRST AID/ FIRE FIGHTING FIRE Combustible. Gives off irritating or toxic fumes (or gases) in a fire. NO open flames. Foam, carbon dioxide, powder . EXPLOSION EXPOSURE  •INHALATION Cough. Headache. Nausea. Ventilation. Fresh air, rest.  •SKIN Redness. 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 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. Carefully collect remainder. Separated from strong oxidants, reducing agents, metals , acids. R: S: SEE IMPORTANT INFORMATION ON BACK ICSC: 0025 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 1-HEXADECANETHIOL ICSC: 0025 I M P O R T A N T D A T A PHYSICAL STATE; APPEARANCE: LIQUID , WITH CHARACTERISTIC ODOUR. PHYSICAL DANGERS: CHEMICAL DANGERS: The substance decomposes on burning producing toxic gases including sulfur oxides . Reacts violently with strong oxidants , acids , reducing agents , metals . OCCUPATIONAL EXPOSURE LIMITS: TLV not established. MAK not established. OSHA PEL: none NIOSH REL: C 0.5 ppm (5.3 mg/m3) 15-minute NIOSH IDLH: No data ROUTES OF EXPOSURE: INHALATION RISK: A harmful contamination of the air will not or will only very slowly be reached on evaporation of this substance at 20°C EFFECTS OF SHORT-TERM EXPOSURE: The substance is mildly irritating to the eyes , the skin and the respiratory tract . EFFECTS OF LONG-TERM OR REPEATED EXPOSURE: PHYSICAL PROPERTIES Melting point: 18°C Relative density (water = 1): 0.84 Solubility in water: none Vapour pressure, Pa at 20°C: 10 Relative vapour density (air = 1): 8.9 Relative density of the vapour/air-mixture at 20°C (air = 1): 1.00 Flash point: 135°C o.c. ENVIRONMENTAL DATA N O T E S Auto-ignition temperature is unknown in literature. Health effects of exposure to the substance have not been investigated adequately. ADDITIONAL INFORMATION ICSC: 0025 1-HEXADECANETHIOL (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.