General Description
A clear colorless liquid with a strong foul odor. Flash point 99°F. Denser than water and insoluble in water. Vapors heavier than air. Used to make other chemicals.
Reactivity Profile
As soon as TRIMETHYL PHOSPHITE(121-45-9) contacted a small amount of magnesium perchlorate in a flask, there was a flash and an explosion that shattered the flask (Allison 1968).
Air & Water Reactions
Highly flammable. Insoluble in water and denser than water. Slowly reacts with water to form phosphoric acid and corresponding organic alcohol.
Health Hazard
Symptoms of exposure may include burning sensation, coughing, wheezing, laryngitis, shortness of breath, headache, nausea, and vomiting.
Potential Exposure
Trimethyl phosphite is a flame
retardant, and used as an intermediate in the manufacture
of a number of pesticides, and organophosphorus
additives.
Fire Hazard
Special Hazards of Combustion Products: Toxic fumes of PO x
First aid
If this chemical gets into the eyes, remove any
contact lenses at once and irrigate immediately for at least
15 minutes, occasionally lifting upper and lower lids. Seek
medical attention immediately. If this chemical contacts the
skin, remove contaminated clothing and wash immediately
with soap and water. Seek medical attention immediately. If
this chemical has been inhaled, remove from exposure, begin
rescue breathing (using universal precautions, including
resuscitation mask) if breathing has stopped and CPR if heart
action has stopped. Transfer promptly to a medical facility.
When this chemical has been swallowed, get medical attention.
Give large quantities of water and induce vomiting. Do
not make an unconscious person vomit. Medical observation
is recommended for 24-48 hours after breathing overexposure,
as pulmonary edema may be delayed. As first aid for
pulmonary edema, a doctor or authorized paramedic may consider
administering a drug or other inhalation therapy.
Shipping
UN2329 Trimethyl phosphite, Hazard Class: 3;
Labels: 3-Flammable liquid.
Incompatibilities
Vaor May form explosive mixture with
air. Incompatible with oxidizers (chlorates, nitrates, peroxides,
permanganates, perchlorates, chlorine, bromine, fluorine,
etc.); contact may cause fires or explosions. Violent
reaction with magnesium perchlorate.
Keep away from alkaline materials, strong bases, strong
acids, oxoacids, epoxides. Reacts (hydrolyzes) with water.
Incompatible with air, moisture.
Chemical Properties
Trimethyl phosphite is a colorless liquid.
Distinctive pungent, pyridine-like odor. The Odor
Threshold is 0.0001 ppm.
Production Methods
Produced via a reaction between phosphorus trichloride and
methanol in the presence of a tertiary amine catalyst such as
diethylaniline.
Carcinogenicity
Trimethyl phosphite was genotoxic in
mouse lymphoma assays but was not mutagenic
in various bacterial assays.
Purification Methods
Treat the phosphite with Na (to remove water and any dialkyl phosphonate), then decant and distil it with protection against moisture. It has also been treated with sodium wire for 24hours, then distilled in an inert atmosphere onto activated molecular sieves [Connor et al. J Chem Soc, Dalton Trans 511 1986]. It can be fractionally distilled using a spinning band column at high reflux ratio. It is a colourless liquid which is slowly hydrolysed by H2O. [Gillis et al. J Am Chem Soc 80 2999 1958, NMR: Callis et al. J Am Chem Soc 79 2719 1957, Kosolapoff Organophosphorus Compounds, Wiley p 203 1950, Beilstein 1 IV 1256.]
Waste Disposal
Trimethyl phosphite may be burned in a chemical incinerator equipped with an afterburner and scrubber.
