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DIMETHYL HYDROGEN PHOSPHITE ICSC: 1599
Date of Peer Review: October 2005

Dimethylphosphite
Dimethyl hydrogen phosphonate
Phosphorous acid dimethyl ester
Dimethylphosphonate
CAS # 868-85-9 C2H7O3P
RTECS # SZ7710000 Molecular mass: 110.1
UN #
EC Index #
TYPES OF HAZARD / EXPOSURE ACUTE HAZARDS / SYMPTOMS PREVENTION FIRST AID / FIRE FIGHTING
FIRE Combustible.
NO open flames, NO sparks, and NO smoking.
Foam. Alcohol-resistant foam. Carbon dioxide.
EXPLOSION Above 70C explosive vapour/air mixtures may be formed.
Above 70C use a closed system, ventilation.
In case of fire: cool drums, etc., by spraying with water but avoid contact of the substance with water. Combat fire from a sheltered position.
EXPOSURE


Inhalation Cough. Nausea. Sore throat.
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, then remove contaminated clothes and rinse again.
Eyes Redness. Pain.
Safety goggles.
First rinse with plenty of water for several minutes (remove contact lenses if easily possible), then take to a doctor.
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: filter respirator for acid gases. Chemical protection suit. Do NOT let this chemical enter the environment. Cover the spilled material with absorbent. Collect leaking liquid in sealable containers.
EU Classification
UN Classification

EMERGENCY RESPONSE STORAGE

Dry. Store in an area without drain or sewer access. Separated from food and feedstuffs. See Chemical Dangers.
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
DIMETHYL HYDROGEN PHOSPHITE ICSC: 1599
IMPORTANT DATA
PHYSICAL STATE; APPEARANCE:
COLOURLESS LIQUID

PHYSICAL DANGERS:
The vapour is heavier than air.

CHEMICAL DANGERS:
The substance decomposes rapidly on heating producing toxic fumes including phosphorus oxides and phosphine; on contact with moist air above 220C producing 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 20C; on spraying or dispersing, however, much faster.

EFFECTS OF SHORT-TERM EXPOSURE:
The substance is irritating to the eyes and the skin.

EFFECTS OF LONG-TERM OR REPEATED EXPOSURE:
The substance may have effects on the eyes, resulting in cataract.
PHYSICAL PROPERTIES
Boiling point: 171C
Melting point: < -60C
Relative density (water = 1): 1.2
Solubility in water, g/100 ml at 20C: >10
Vapour pressure, kPa at 20C: 0.135
Flash point: 70C c.c.
Auto-ignition temperature: 237C
Explosive limits, vol% in air: 5.8-38.1
Octanol/water partition coefficient as log Pow: -1.2
ENVIRONMENTAL DATA
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


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