Agent Name

Trimethyl phosphite

CAS Number

121-45-9

Formula

C3-H9-O3-P

Major Category

Other Classes

Synonyms

Fosforyn trojmetylowy [Czech]; Trimethoxyfosfin [Czech]; Trimethoxyphosphine; Trimethyl phosphite; Trimethylfosfit [Czech]; [ChemIDplus] UN2329

Category

Phosphite Compounds

Description

Colorless liquid with a distinctive, pungent odor; [NIOSH]

Sources/Uses

Used in the manufacture of pesticides, flame-retardant textiles, and polyurethane foams; also used as a catalyst; [ACGIH]

Comments

Corrosive to skin; [Quick CPC] Liquid causes second or third degree burns after short contact. [CHRIS] Dose dependent cataract formation occurs in rats exposed to concentrations above 100 ppm. Lung inflammation occurs in animals exposed at 600 ppm. Human subjects complain of objectionable odor above 20 ppm. No adverse health effects were found in 179 employees exposed regularly to 0.3 to 8 ppm. [ACGIH] A severe skin, eye, and respiratory tract irritant; [ICSC]

Exposure Assessment
Skin Designation (ACGIH)

Insufficient data

TLV (ACGIH)

2 ppm

Vapor Pressure

18.7 mm Hg

Odor Threshold Low

0.001 ppm

Lethal Concentration

LCLo (rat) = 32,700 mg/m3/6h

Explanatory Notes

Odor threshold from AIHA; Flash pint = 54 deg C;

Adverse Effects
Toxic Pneumonitis

Yes

Dermatotoxin

Skin Burns

Links to Other NLM Databases
Health Studies

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Toxicity Information

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Chemical Information

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Related Information in HazMap
Processes

Industrial Processes with risk of exposure: