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TRIMETHYL PHOSPHITE ICSC: 1556
Date of Peer Review: October 2004

Phophorous acid, trimethyl ester
Trimethoxy phosphine
Methyl phosphite
CAS # 121-45-9 C3H9O3P / (CH3O)3P
RTECS # TH1400000 Molecular mass: 124.1
UN # 2329
EC Index #
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 23C explosive vapour/air mixtures may be formed.
Above 23C 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 PACKAGING & LABELLING
Collect leaking and spilled liquid in sealable containers as far as possible. Personal protection: self-contained breathing apparatus.
EU Classification
UN Classification
UN Hazard Class: 3
UN Pack Group: III
EMERGENCY RESPONSE STORAGE
Transport Emergency Card: TEC (R)-30GF1-III
NFPA Code: H1; F3; R1;
Fireproof. Separated from oxidants, strong bases.
IPCS
International
Programme on
Chemical Safety
Prepared in the context of cooperation between the International Programme on Chemical Safety and the Commission of the European Communities IPCS, CEC 2005

SEE IMPORTANT INFORMATION ON BACK
TRIMETHYL PHOSPHITE ICSC: 1556
IMPORTANT DATA
PHYSICAL STATE; APPEARANCE:
COLOURLESS LIQUID, WITH PUNGENT ODOUR.

CHEMICAL DANGERS:
On combustion, forms toxic fumes including phosphine and phosphorous 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 (not established but data is available); skin absorption (H); (DFG 2004).
ROUTES OF EXPOSURE:
The substance can be absorbed into the body through the skin and by ingestion.

INHALATION RISK:
A harmful contamination of the air can be reached very quickly on evaporation of this substance at 20C.

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: 111.5C
Melting point: -78C
Relative density (water = 1): 1.1
Solubility in water: reaction
Vapour pressure, kPa at 25C: 3.2
Relative vapour density (air = 1): 4.3
Flash point: 23C c.c.
Auto-ignition temperature: 250 C
ENVIRONMENTAL DATA

NOTES
Environmental effects from the substance have not been investigated.
ADDITIONAL INFORMATION


LEGAL NOTICE Neither the CEC nor the IPCS nor any person acting on behalf of the CEC or the IPCS is responsible for the use which might be made of this information
IPCS, CEC 2005