International Chemical Safety Cards TRIMETHYL PHOSPHITE ICSC: 1556 Phophorous acid, trimethyl ester Trimethoxy phosphine Methyl phosphite C3H9O3P / (CH3O)3P Molecular mass: 124.1 ICSC #    1556 CAS #     121-45-9 RTECS # TH1400000 UN #        2329 October 26, 2004 Peer reviewed TYPES OF HAZARD/ EXPOSURE ACUTE HAZARDS/ SYMPTOMS PREVENTION FIRST AID/ FIRE FIGHTING FIRE Flammable. Gives off irritating or toxic fumes (or gases) in a fire. NO open flames, NO sparks, and NO smoking. Foam, carbon dioxide, powder . EXPLOSION Above 23°C explosive vapour/air mixtures may be formed. Above 23°C use a closed system, ventilation, and explosion-proof electrical equipment. In case of fire: cool drums, etc., by spraying with water but avoid contact of the substance with water. EXPOSURE AVOID EXPOSURE OF (PREGNANT) WOMEN!  •INHALATION Cough. Sore throat. Ventilation, local exhaust, or breathing protection. Fresh air, rest.  •SKIN Redness. Pain. 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 Collect leaking and spilled liquid in sealable containers as far as possible. Personal protection: self-contained breathing apparatus. Fireproof. Separated from oxidants , strong bases. R: S: UN Hazard Class: 3 UN Packing Group: III SEE IMPORTANT INFORMATION ON BACK ICSC: 1556 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 TRIMETHYL PHOSPHITE ICSC: 1556 I M P O R T A N T D A T A PHYSICAL STATE; APPEARANCE: COLOURLESS LIQUID , WITH PUNGENT ODOUR. PHYSICAL DANGERS: CHEMICAL DANGERS: On combustion, forms toxic fumesincludingphosphineandphosphorous oxides. Reacts with water producing methanol and dimethyl phosphite. Reacts with oxidants and strong bases . Reacts with magnesium perchlorate causing explosion hazard. OCCUPATIONAL EXPOSURE LIMITS: TLV: 2 ppm (as TWA); (ACGIH 2004). MAK: IIb, value not established but data is available; H skin absorption; (DFG 2004). ROUTES OF EXPOSURE: The substance can be absorbed into the body through the skin by ingestion. INHALATION RISK: A harmful contamination of the air can be reached very quickly on evaporation of this substance at 20°C. EFFECTS OF SHORT-TERM EXPOSURE: The substance is severely irritating to the eyes and the skin . The vapour is irritating to the respiratory tract . EFFECTS OF LONG-TERM OR REPEATED EXPOSURE: Animal tests show that this substance possibly causes toxicity to human reproduction or development. PHYSICAL PROPERTIES Boiling point at kPa: 111.5°C Melting point: -78°C Relative density (water = 1): 1.1 Solubility in water: reaction Vapour pressure, kPa at 25°C: 3.2 Relative vapour density (air = 1): 4.3 Flash point: 23°C c.c. Auto-ignition temperature: 250 °C ENVIRONMENTAL DATA N O T E S Environmental effects from the substance have not been investigated. Transport Emergency Card: TEC (R)-30GF1-III NFPA Code: H1; F3; R1; ADDITIONAL INFORMATION ICSC: 1556 TRIMETHYL PHOSPHITE (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.