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DIMETHYL HYDROGEN PHOSPHITE
ICSC: 1599
Peer-Review Status: 20.10.2005 Validated
Dimethylphosphite
Dimethyl hydrogen phosphonate
Phosphorous acid dimethyl ester
Dimethylphosphonate 
CAS #: 868-85-9 RTECS #: SZ7710000
EINECS #: 212-783-8
    Formula: C2H7O3P
Molecular mass: 110.1

TYPES OF
HAZARD /
EXPOSURE
ACUTE HAZARDS / SYMPTOMS      PREVENTION      FIRST AID / FIRE FIGHTING
FIRE Combustible.  NO open flames, NO sparks and NO smoking.  Use foam, alcohol-resistant foam, carbon dioxide. 
EXPLOSION Above 70°C explosive vapour/air mixtures may be formed.  Above 70°C use a closed system and ventilation.  In case of fire: keep drums, etc., cool by spraying with water. NO direct contact with water. Combat fire from a sheltered position. 
 
EXPOSURE      
Inhalation Cough. Nausea. Sore throat.  Use ventilation, local exhaust or breathing protection.  Fresh air, rest. Refer for medical attention. 
Skin MAY BE ABSORBED! Redness. Pain.  Protective clothing. Protective gloves.  First rinse with plenty of water for at least 15 minutes, then remove contaminated clothes and rinse again. 
Eyes Redness. Pain.  Wear safety goggles.  First rinse with plenty of water for several minutes (remove contact lenses if easily possible), then refer for medical attention. 
Ingestion Diarrhoea. Nausea. Vomiting.  Do not eat, drink, or smoke during work.  Rinse mouth. Do NOT induce vomiting. Refer for medical attention . 

SPILLAGE DISPOSAL
PACKAGING & LABELLING
Personal protection: chemical protection suit and filter respirator for acid gases and vapours adapted to the airborne concentration of the substance. Do NOT let this chemical enter the environment. Cover the spilled material with inert absorbent. Collect leaking and spilled liquid in sealable containers as far as possible.   
EC Classification
 
UN Classification
 
GHS Classification
 

EMERGENCY RESPONSE SAFE STORAGE
  Dry. Store in an area without drain or sewer access. Separated from food and feedstuffs. See Chemical Dangers. 

IMPORTANT DATA
Physical State; Appearance
COLOURLESS LIQUID. 

Physical dangers
The vapour is heavier than air. 

Chemical dangers
Decomposes rapidly on heating. This produces toxic fumes including phosphorus oxides and phosphine. Decomposes on contact with moist air above 220°C. This produces phosphoric acid and methanol. The solution in water is a strong acid. It reacts violently with bases and is corrosive. Reacts violently with acids and oxidants. 

Occupational exposure limits
TLV (NOT-ESTABLISHED):.
MAK: Carcinogen category: 3B; (DFG 2005). 

Routes of exposure
The substance can be absorbed into the body by inhalation, through the skin and by ingestion. 

Inhalation risk
A harmful contamination of the air will be reached slowly on evaporation of this substance at 20°C; on spraying or dispersing, however, much faster. 

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

Effects of long-term or repeated exposure
The substance may have effects on the eyes. This may result in cataract. 


PHYSICAL PROPERTIES ENVIRONMENTAL DATA
Boiling point: 171°C
Melting point: <-60°C
Relative density (water = 1): 1.2
Solubility in water, g/100ml at 20°C: >10
Vapour pressure, kPa at 20°C: 0.135
Flash point: 70°C c.c.
Auto-ignition temperature: 237°C
Explosive limits, vol% in air: 5.8-38.1
Octanol/water partition coefficient as log Pow: -1.2  
The substance is harmful to aquatic organisms. 

NOTES
Do NOT use in the vicinity of a fire or a hot surface, or during welding. 

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
       Dimethyl Hydrogen Phosphite  (IARC Summary & Evaluation, Volume 48, 1990)
       Dimethyl Hydrogen Phosphite  (IARC Summary & Evaluation, Volume 71, 1999)