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TRIMETHYL PHOSPHITE
ICSC: 1556
Peer-Review Status: 26.10.2004 Validated
Phophorous acid, trimethyl ester
Trimethoxy phosphine
Methyl phosphite 
CAS #: 121-45-9 RTECS #: TH1400000
UN #: 2329
EINECS #: 204-471-5
    Formula: C3H9O3P / (CH3O)3P
Molecular mass: 124.1

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.  Use 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: keep drums, etc., cool by spraying with water. NO direct contact with water. 
 
EXPOSURE   AVOID EXPOSURE OF (PREGNANT) WOMEN!   
Inhalation Cough. Sore throat.  Use 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.  Wear safety spectacles.  First rinse with plenty of water for several minutes (remove contact lenses if easily possible), then refer for medical attention. 
Ingestion   Do not eat, drink, or smoke during work.  Rinse mouth. 

SPILLAGE DISPOSAL
PACKAGING & LABELLING
Personal protection: self-contained breathing apparatus. Collect leaking and spilled liquid in sealable containers as far as possible.   
EC Classification
 
UN Classification
UN Hazard Class: 3; UN Pack Group: III 
GHS Classification
 

EMERGENCY RESPONSE SAFE STORAGE
Transport Emergency Card: TEC (R)-30GF1-III.
NFPA Code: H1; F3; R1. 
Fireproof. Separated from oxidants and strong bases. 

IMPORTANT DATA
Physical State; Appearance
COLOURLESS LIQUID WITH PUNGENT ODOUR. 

Physical dangers
 

Chemical dangers
On combustion, forms toxic fumes including phosphine and phosphorus oxides. Reacts with water. This produces methanol and dimethyl phosphite. Reacts with oxidants and strong bases. Reacts with magnesium perchlorate. This generates explosion hazard. 

Occupational exposure limits
TLV: 2ppm as TWA; (ACGIH 2004).
MAK: 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 20°C. 

Effects of short-term exposure
The substance is severely irritating to the eyes and skin. 

Effects of long-term or repeated exposure
Animal tests show that this substance possibly causes toxicity to human reproduction or development. 


PHYSICAL PROPERTIES ENVIRONMENTAL DATA
Boiling point: 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  
 

NOTES
Environmental effects from the substance have not been investigated. 

ADDITIONAL INFORMATION
 

IPCS
International
Programme on
Chemical Safety
WHO ILO EC Prepared in the context of cooperation between the International Programme on Chemical Safety and the European Commission
© IPCS 2004-2012
LEGAL NOTICE Neither the EC nor the IPCS nor any person acting on behalf of the EC or the IPCS is responsible for the use which might be made of this information.


    See Also:
       Toxicological Abbreviations