Triethyl phosphite

Excerpt from ERG Guide 130 [Flammable Liquids (Water-Immiscible / Noxious)]:

Use powder, foam, carbon dioxide. NO hydrous agents. NO water. In case of fire: keep drums, etc., cool by spraying with water. NO direct contact with water.

Fresh air, rest.

Remove contaminated clothes. Rinse skin with plenty of water or shower. Refer for medical attention .

First rinse with plenty of water for several minutes (remove contact lenses if easily possible), then refer for medical attention.

Rinse mouth. Refer for medical attention .

· CALL 911. Then call emergency response telephone number on shipping paper. If shipping paper not available or no answer, refer to appropriate telephone number listed on the inside back cover.

· ELIMINATE all ignition sources (no smoking, flares, sparks or flames) from immediate area.

INHALATION: CALL FOR MEDICAL ASSISTANCE. Remove to fresh air. Treat symptomatically. If not breathing, give artificial respiration.

General First Aid:

Suitable extinguishing media: Use water spray, alcohol-resistant foam, dry chemical, or carbon dioxide.

Advice for firefighters: Wear self-contained breathing apparatus for firefighting if necessary.

Use water spray to cool unopened containers.

In case of fire: cool drums, etc., by spraying with water but avoid contact of the substance with water.

ACCIDENTAL RELEASE MEASURES: Personal precautions, protective equipment and emergency procedures: Use personal protective equipment. Avoid breathing vapors, mist or gas. Ensure adequate ventilation. Remove all sources of ignition. Beware of vapors accumulating to form explosive concentrations. Vapors can accumulate in low areas. Environmental precautions: Prevent further leakage or spillage if safe to do so. Do not let product enter drains. Discharge into the environment must be avoided. Methods and materials for containment and cleaning up: Contain spillage, and then collect with an electrically protected vacuum cleaner or by wet-brushing and place in container for disposal according to local regulations.

SRP: Recycle any unused portion of the material for its approved use or return it to the manufacturer or supplier. Ultimate disposal of the chemical must consider: the material's impact on air quality; potential migration in air, soil or water; effects on animal, aquatic and plant life; and conformance with environmental and public health regulations. If it is possible or reasonable use an alternative chemical product with less inherent propensity for occupational harm/injury/toxicity or environmental contamination.

SRP: Wastewater from contaminant suppression, cleaning of protective clothing/equipment, or contaminated sites should be contained and evaluated for subject chemical or decomposition product concentrations. Concentrations shall be lower than applicable environmental discharge or disposal criteria. Alternatively, pretreatment and/or discharge to a permitted wastewater treatment facility is acceptable only after review by the governing authority and assurance that "pass through" violations will not occur. Due consideration shall be given to remediation worker exposure (inhalation, dermal and ingestion) as well as fate during treatment, transfer and disposal. If it is not practicable to manage the chemical in this fashion, it must be evaluated in accordance with EPA 40 CFR Part 261, specifically Subpart B, in order to determine the appropriate local, state and federal requirements for disposal.

Product: Burn in a chemical incinerator equipped with an afterburner and scrubber but exert extra care in igniting as this material is highly flammable. Offer surplus and non-recyclable solutions to a licensed disposal company; Contaminated packaging: Dispose of as unused product.

Personal protection: filter respirator for organic gases and vapours adapted to the airborne concentration of the substance. Ventilation. Collect leaking and spilled liquid in sealable containers as far as possible. Absorb remaining liquid in sand or inert absorbent. Then store and dispose of according to local regulations.

EC50; Species: Scenedesmus subspicatus (Alga); Conditions: static, 21-25 °C, pH 8-10; Concentration: >73.6 mg/L for 72 hr; Effect: decreased growth rate and biomass /purity 98.8%/ /calculated from diethyl phosphite/

LC50; Species: Daphnia magna /(water flea)/ age 6-24 hr; Conditions: static, 19.1-19.4 °C; pH 6.9-8; Concentration: 94.1 mg/L for 24 hr /calculated from diethyl phosphite/

LC50; Species: Brachydanio rerio (Fish) age 7 months, length 2.5-3.5 cm; Conditions: static, 20.9-22.6 °C; Concentration: 251.6 mg/L for 96 hr /calculated from diethyl phosphite/ /purity 98.8%/

TERRESTRIAL FATE: Triethyl phosphite hydrolyzes rapidly in the presence of water(1) and, therefore, adsorption to soil, volatilization from moist soil surfaces, and biodegradation are not expected to be important fate processes(SRC). In acid solution (pH = 4), triethyl phosphite hydrolyzes immediately forming diethyl phosphite and ethanol(1). At pH 7, triethyl phosphite hydrolyzes completely within 20 minutes; after 3 hours 89.3% diethyl phosphite and 10.7% monoethyl phosphite are formed(1). At pH 9, the half-life of triethyl phosphite in water is approximately 5.1 hours; 70% of the substance remains unhydrolyzed after 3 hours(1). Triethyl phosphite is expected to volatilize from dry soil surfaces(SRC) based upon a vapor pressure of 1.95 mm Hg(1). Results of standard biodegradation tests indicate triethyl phosphite is inherently biodegradable; however, the tests are likely measuring the biodegradability of the hydrolysis products(1,2).

AQUATIC FATE: Triethyl phosphite hydrolyzes rapidly in the presence of water(1) and, therefore, adsorption to sediment, volatilization from water surfaces, bioconcentration and biodegradation are not expected to be important fate processes(SRC). In acid solution (pH = 4), triethyl phosphite hydrolyzes immediately forming diethyl phosphite and ethanol(1). At pH 7, triethyl phosphite hydrolyzes completely within 20 minutes; after 3 hours 89.3% diethyl phosphite and 10.7% monoethyl phosphite are formed(1). At pH 9, the half-life of triethyl phosphite in water is approximately 5.1 hours; 70% of the substance remains unhydrolyzed after 3 hours(1). Results of standard biodegradation tests indicate triethyl phosphite is inherently biodegradable; however, the tests are likely measuring the biodegradability of the hydrolysis products(1,2).

ATMOSPHERIC FATE: According to a model of gas/particle partitioning of semivolatile organic compounds in the atmosphere(1), triethyl phosphite, which has a vapor pressure of 1.95 mm Hg at 20 °C(SRC), is expected to exist solely as a vapor in the ambient atmosphere. Vapor-phase triethyl phosphite is degraded in the atmosphere by reaction with photochemically-produced hydroxyl radicals(SRC); the half-life for this reaction in air is estimated to be 6.6 hours(SRC), calculated from its rate constant of 5.8X10-11 cu cm/molecule-sec at 25 °C(SRC) that was derived using a structure estimation method(3). Triethyl phosphite does not absorb at wavelengths >290 nm(4) and therefore is not expected to be susceptible to direct photolysis by sunlight(SRC).

IDENTIFICATION AND USE: Triethyl phosphite is a colorless liquid with a characteristic, obnoxious phosphite odor. It is a chemical intermediate for vinyl phosphate insecticides, for phosphonate insecticides; sugarcane ripener. Schedule 3B precursor to dimethyl methylphosphonate, which is a sarin precursor and nerve agent simulant. HUMAN EXPOSURE AND TOXICITY: Human blood monocyte carboxylesterase is inhibited by triethyl phosphite. ANIMAL STUDIES: Triethyl phosphite showed slightly irritating effects on the eyes of 3 male rabbits. All animals showed slight or clearly visible conjunctival erythema in the treated eyes. Slight chemosis and increased secretion were recorded in two animals, each. The findings appeared within one hr and were completely reversible within 48 hr. Six rabbits revealed slightly irritating effects on the skin after 4 hr of semi-occlusive exposure to the undiluted triethyl phosphite. All animals showed slight or clearly visible erythema at the treated sites up to 48 hr after exposure. At day 7, slight erythema still persisted in 5 animals, but had resolved in all but one animal at day 10. None of the animals showed edema at any of the observations. An acute inhalation study was done with male and female rats. After an exposure period of 6 hours the calculated LC50 was 11.6 mg/L for males and 11.1 mg/L for females. A similar study in mice gave LC50 values of 6.2 and 9.2 mg/L for male and female animals, respectively. In both species, signs of toxic stress included eye and upper respiratory irritation, salivation and rapid, shallow breathing; most deaths occurred within 24 hr following treatment. In developmental study doses of 0, 10, 80, 320 and 640 mg/kg bw/day were used for oral administration (gavage) to rats. Groups of 12 male and female rats each were treated (control group: 15 males and 15 females). F0-Animals were treated from 2 weeks before mating to the end of gestation and up to 6 days of lactation. Males were killed after 36 to 37 days of treatment. Females and pups were killed on days 4 to 6 post partum. Ovaries, mammae, testes, epididymides and macroscopically altered tissues of F0 animals were examined histologically. Parameters of general toxicity and fertility, as well as pre- and post-natal development were recorded. In F1, the sex ratio, mortality and weights were not affected by treatment up to and including doses of 80 mg/kg bw/day, while evaluation was not possible at higher doses as there were no surviving pups. No externally malformed pups were observed. The in vivo micronucleus assay in mice was negative. There was no indication of a potential to induce gene mutations in the Ames test with four different strains of Salmonella typhimurium (TA98, TA100, TA1535, TA1537) both with and without metabolic activation. The test was performed including cytotoxic concentrations.

Redness.

Redness. Pain.

Abdominal pain.

EPA has released the Interactive Chemical Safety for Sustainability (iCSS) Dashboard. The iCSS Dashboard provides an interactive tool to explore rapid, automated (or in vitro high-throughput) chemical screening data generated by the Toxicity Forecaster (ToxCast) project and the federal Toxicity Testing in the 21st century (Tox21) collaboration. /The title compound was tested by ToxCast and/or Tox21 assays/[USEPA; ICSS Dashboard Application; Available from, as of July 7, 2016: http://actor.epa.gov/dashboard/]

/ALTERNATIVE and IN VITRO TESTS/ Human blood monocyte carboxylesterase (CBE) is inhibited by a variety of organophosphorus compounds including arylphosphates and arylphosphites and some alkylphosphites. Triphenyl phosphate and triphenyl phosphite with Ki values of 8 x 10(-9) M and 4.8 x 10(-8) M, respectively, are the most potent inhibitors of this enzyme evaluated by this study. The arylphosphates vary in their capacity to inhibit carboxylesterase activity. Diphenyl phosphate with its strong negative charge is not a potent inhibitor (Ki = 1 x 10(-4) M), whereas if its negative charge is neutralized, as in diphenyl methyl phosphate, its capacity to inhibit carboxylesterase is significantly increased. Compounds with increased bulk, such as trinaphthyl phosphate, only inhibit the enzyme at concentrations of 10(-5) M or greater. Arylphosphites have inhibitory capacities similar to the arylphosphates. Alkylphosphites (tributyl phosphite/triethyl phosphite) inhibit carboxylesterase activity, whereas alkylphosphates (tributyl phosphate/triethyl phosphate) have no inhibitory effect. Arylphosphines and arylphosphine oxides do not inhibit carboxylesterase activity. This study demonstrates that organophosphates and organophosphites are relatively effective inhibitors of human monocyte CBE activity with the exception of the alkylphosphates which have no inhibitory activity. We conclude that molecular bulk and charge have a significant role in determining the potency of organophosphorus inhibitors of monocyte CBE. The observed variations in the degree of esterase inhibition by organophosphorus compounds as well as the differences in the pathological expression of neuropathic disorders associated with such chemicals suggest that different esterase enzymes derived from the family of esterase genes may mediate the different neuropathies observed with organophosphorus exposures. Such data also provide the rationale for the kinetic analyses of esterases and the design of non-toxic organophosphorus compounds with low or no monocyte CBE inhibitory capacity to reduce the potential of these commonly used chemicals for human toxicity.

Triethyl phosphite's production and use an intermediate for the production of flame retardants, optical brighteners, pesticides, antioxidants, and pharmaceuticals(1,2) may result in its release to the environment through various waste streams(SRC).

AEROBIC: In 2 tests on ready biodegradation, triethyl phosphite was degraded by 49-69%, therefore, it did not reach the criteria for ready biodegradability(1). However, from the degradation curve it can be assumed that hydrolysis was the prerequisite for biodegradation(1). Using OECD Guideline 302C (Inherent Biodegradability: Modified MITI Test II) with an activated sludge inoculum, triethyl phosphite was degraded >100% based on O2 consumption and 73% based on DOC removal classifying the compound as inherently biodegradable(2); the complete disappearance of triethyl phosphite to monoethyl and diethyl phosphite and phosphorous acid in the test system is likely the result of hydrolysis followed by biodegradation(1,2). Biodegradation is not expected to be an important fate process for triethyl phosphite(SRC) due to its hydrolysis(1).

Volatilization from water surfaces or moist soil is not expected to be an important fate process(SRC) due to the hydrolysis of triethyl phosphite(1). Triethyl phosphite is expected to volatilize from dry soil surfaces(SRC) based upon a vapor pressure of 1.95 mm at 20 °C(1).

Triethyl phosphite

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Chemical Weapons/Chemical Weapons Precursors chemical material that, if stolen or diverted, can be converted into weapons using simple chemistry, equipment, or techniques.