Trimethyl phosphite

Other Classes -> Phosphite Compounds

Flammable agents - 3rd degree

Irritating, pungent, oily, pyridine-like odor

Distinctive, pungent odor.

Powerful, sickly odor

1.046 at 68 °F (USCG, 1999) - Denser than water; will sink

1.0518 g/cu cm at 20 °C

Relative density (water = 1): 1.1

1.046

1.046 @25 °C

1.05

Reacts with water (NIOSH, 2024)

Reacts (hydrolyzes) with water

Very soluble in ethanol, ether

Soluble in hexane, benzene, acetone, carbon tetrachloride, and kerosene

Solubility in water: reaction

Reacts

82 °F (USCG, 1999)

28 °C (82 °F) - closed cup

130 °F (54 °C) (open cup)

23 °C c.c.

82 °F

82 °F

232 °F at 760 mmHg (USCG, 1999)

110 °C

111.5 °C

232 °F

232 °F

Hazardous decomposition products formed under fire conditions - Carbon oxides, oxides of phosphorus.

... When heated to decomposition can emit highly toxic fumes of /phosphorus oxides/.

-108 °F (USCG, 1999)

-78 °C

-78 °C

-108 °F

-78 °C

-108 °F

4.3 (Air = 1)

Relative vapor density (air = 1): 4.3

Odor Threshold Low: 0.001 [ppm]

Odor threshold (tested by means of a laboratory test panel) are on the order of 0.1 ppb.

Danger

H226 (99.6%): Flammable liquid and vapor [Warning Flammable liquids]

P203, P210, P233, P240, P241, P242, P243, P261, P264, P264+P265, P270, P271, P280, P301+P317, P302+P352, P303+P361+P353, P304+P340, P305+P351+P338, P305+P354+P338, P317, P318, P319, P321, P330, P332+P317, P337+P317, P362+P364, P370+P378, P403+P233, P403+P235, P405, and P501 (click each P-code to see the statement)

Aggregated GHS information provided per 236 reports by companies from 15 notifications to the ECHA C&L Inventory. Each notification may be associated with multiple companies.

Danger

H226: Flammable liquid and vapor [Warning Flammable liquids]

Chemical: Phosphorous acid, trimethyl ester

Phosphorous acid, trimethyl ester is listed on the EPA's Chemical Data Reporting (CDR) system. Manufacturers and importers of Phosphorous acid, trimethyl ester are required to report information about their production and use of this chemical to the EPA under the Toxic Substances Control Act (TSCA). (40 eCFR Part 711)

Status: Active Update: 22-03-2018 https://echa.europa.eu/registration-dossier/-/registered-dossier/13214

Phosphorous acid, trimethyl ester: HSNO Approval: HSR001231 Approved with controls

The New Jersey Worker and Community Right to Know Act requires public and private employers to provide information about hazardous substances at their workplaces. (N.J.S.A. 34:5A-1 et. seq.)

Special Hazards of Combustion Products: Toxic fumes of POx. (USCG, 1999)

· HIGHLY FLAMMABLE: Will be easily ignited by heat, sparks or flames.

Flammable. Gives off irritating or toxic fumes (or gases) in a fire. Above 23 °C explosive vapour/air mixtures may be formed.

Symptoms of exposure may include burning sensation, coughing, wheezing, laryngitis, shortness of breath, headache, nausea, and vomiting. (USCG, 1999)

· May cause toxic effects if inhaled or absorbed through skin.

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]

2329 130

2329 130

Organization for the Prohibition of Chemical Weapons; Convention on the Prohibition of the Development, Production, Stockpiling and Use of Chemical Weapons and Their Destruction. The Chemical Weapons Convention (CWC) is an international treaty which bans the development, production, stockpiling, and transfer or use of chemical weapons. The Convention mandates the destruction and prohibition of chemical weapons and related facilities and provides for restrictions on international trade in toxic chemicals and precursors.[Available from, as of November 12, 2008: http://www.opcw.org]

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

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

Fresh air, rest.

Rinse and then wash skin with water and soap.

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

Rinse mouth.

· 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.

Excerpt from NIOSH Pocket Guide for Trimethyl phosphite:

General First Aid:

(General first aid procedures)

Suitable extinguishing media: Dry powder.

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

To fight fire, use water, foam, fog, /carbon dioxide/.

Keep container tightly closed in a dry and well-ventilated place. Containers which are opened must be carefully resealed and kept upright to prevent leakage. Never allow product to get in contact with water during storage. Storage class (TRGS 510): Flammable liquids.

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. Evacuate personnel to safe areas. 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. 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. Do not flush with water.

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. Contact a licensed professional waste disposal service to dispose of this material; Contaminated packaging: Dispose of as unused product.

Principles and methods for destruction of chemical weapons: ... "Destruction of chemical weapons" means a process by which chemicals are converted in an essentially irreversible way to a form unsuitable for production of chemical weapons, and which in an irreversible manner renders munitions and other devices unusable as such. ... Each ... /nation/ shall determine how it shall destroy chemical weapons, except that the following processes may not be used: dumping in any body of water, land burial or open-pit burning. It shall destroy chemical weapons only at specifically designated and appropriately designed and equipped facilities. ... Each ... /nation/ shall ensure that its chemical weapons destruction facilities are constructed and operated in a manner to ensure the destruction of the chemical weapons; and that the destruction process can be verified under the provisions of this Convention.

TERRESTRIAL FATE: Trimethyl phosphite hydrolyzes rapidly in the presence of water(1,2) and therefore, adsorption to soil, volatilization from moist soil surfaces, and biodegradation are not expected to be important fate processes(SRC). The hydrolysis rate of trimethyl phosphite is expected to be similar to the hydrolysis rate of triethyl phosphite(SRC). In acid solution (pH=4) triethyl phosphite hydrolyzes immediately forming diethyl phosphite and ethanol(3). At pH 7, triethyl phosphite hydrolyzes completely within 20 minutes; after 3 hours 89.3% diethyl phosphite and 10.7% monoethyl phosphite are formed(3). 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(3). Trimethyl phosphite is expected to volatilize from dry soil surfaces(SRC) based upon a vapor pressure of 24 mm Hg at 25 °C(4). Dimethyl phosphite, an hydrolysis product of trimethyl phosphite, reached 48% of its theoretical BOD in 4 weeks in the Japanese MITI test indicating it is inherently biodegradable, but not readily biodegradable(1).

AQUATIC FATE: Trimethyl phosphite hydrolyzes rapidly in the presence of water(1,2) and therefore, adsorption to sediment, volatilization from water surfaces, bioconcentration and biodegradation are not expected to be important fate processes(SRC). Trimethyl phosphite hydrolyzes in water to form dimethyl phosphite and methanol(1,2). The hydrolysis rate of trimethyl phosphite is expected to be similar to the hydrolysis rate of triethyl phosphite(SRC). In acid solution (pH=4) triethyl phosphite hydrolyzes immediately forming diethyl phosphite and ethanol(3). At pH 7, triethyl phosphite hydrolyzes completely within 20 minutes; after 3 hours 89.3% diethyl phosphite and 10.7% monoethyl phosphite are formed(3). 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(3). Dimethyl phosphite, an hydrolysis product of trimethyl phosphite, reached 48% of its theoretical BOD in 4 weeks in the Japanese MITI test indicating it is inherently biodegradable, but not readily biodegradable(1).

ATMOSPHERIC FATE: According to a model of gas/particle partitioning of semivolatile organic compounds in the atmosphere(1), trimethyl phosphite, which has a vapor pressure of 24 mm Hg at 25 °C(2), is expected to exist solely as a vapor in the ambient atmosphere. Vapor-phase trimethyl 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 33 minutes(SRC), calculated from its rate constant of 7.1X10-10 cu cm/molecule-sec at 25 °C(3). Trimethyl phosphite does not absorb at wavelengths >290 nm(4) and therefore is not expected to be susceptible to direct photolysis by sunlight(SRC).

The substance can be absorbed into the body through the skin and by ingestion.

inhalation, ingestion, skin and/or eye contact

IDENTIFICATION AND USE: Trimethyl phosphite (TMP) is a colorless liquid. It is used primarily as an intermediate in the manufacture of pesticides. It is also used as a fireproofing agent in the production of textiles, as an intermediate in the production of flame-retardant polymers for polyurethane foams, and as a catalyst. HUMAN EXPOSURE AND TOXICITY: Examination of 179 employees involved in manufacturing of TMP failed to reveal any indications of ocular changes or other adverse effects on worker health associated with occupational exposure to trimethyl phosphite. It is only moderately toxic by oral ingestion and an irritant to eyes, skin and upper respiratory system. ANIMAL STUDIES: Topical application of trimethyl phosphite produced moderately severe but persistent irritation on rabbit skin. Instillation of undiluted trimethyl phosphite into the rabbit eye caused severe ocular irritation and swelling, which lasted for several days. No permanent damage to the eye could be detected. Marked mortality (> 70%) /was demonstrated/ among rats exposed at 600 ppm, 6 hours/day, 5 days/week for 4 weeks. Ten percent of the rats exposed at 300 ppm also died. Gross histological evidence of lung inflammation was observed in the animals exposed at 600 ppm, but no such changes occurred in those subjected to 300 or 100 ppm. Clinical signs of ocular irritation occurred in the animals exposed at 100 ppm or higher concentrations. Severe cataract developed in the 600 ppm exposure group, and mild cataracts from 300 ppm; 100 ppm exposures caused mild, reversible "striate opacities" of the lenses of a few animals. TMP was administered by gavage to pregnant rats at rates of 16, 49, or 164 mg/kg/day, on gestation Days 6 through 15. Acetyl salicylic acid (250 mg/kg/day) was also administered to a group of rats as a positive control. Teratologic evaluation revealed gross fetal abnormalities, skeletal defects, and soft tissue defects at a dose rate of 164 mg/kg/day of trimethyl phosphite, but not at the two lesser rates. An increased frequency of fetal resorption was also observed at 164 mg/kg/day. Trimethyl phosphite was genotoxic in three separate mouse lymphoma assays, either with or without microsomal activation. Trimethyl phosphite was also positive in a battery of Drosophila melanogaster mutagenicity assays and in a bacterial DNA damage/repair suspension assay using various strains of Escherichia coli and Salmonella typhimurium. Trimethyl phosphite failed to show evidence for genetic toxicity in Salmonella and Saccharomyces strains, in a cell transformation assay, in a bacterial DNA repair assay (Escherichia coli, Salmonella typhimurium) or in two Salmonella/mammalian-microsome preincubation assays.

Cough. Sore throat.

Redness. Pain.

Redness. Pain.

irritation eyes, skin, upper respiratory system; dermatitis; In Animals: teratogenic effects

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/]

The ability of 1,3-dioxolane to induce morphological transformation in the C3H/10T 1/2 mouse cell line (Cell Transformation Assay) without metabolic activation was evaluated. Based on preliminary toxicity tests (exposure time=24 hrs), 1,3-dioxolane was tested at 10 concentrations between 1.0-20,000 ul/ml, with cell survival ranging from 100% to 66%. 1,3-Dioxolane exhibited a weak transformation potential using this test system.

Teratogenicity was evaluated in pregnant female BLU:(SD)BR albino rats (25/group) orally exposed by gavage to trimethyl phosphite at dose levels of 0, 16, 49 or 164 mg/kg/day on gestation days (GD) 6-15. Surviving animals were sacrificed on GD 20. Significant differences were observed between treated and control animals in the following (high-dose group unless otherwise noted): decreased body weight minus gravid uterine weight, increased incidence of morphological abnormalities in soft tissues and skeletal system and gross abnormalities (including widening of cal sutures, increased incidence of abnormalities, primarily partial ossification of the long bones, along with anomalies of several sternebrae and vertebrae, and all treated groups exhibited increased incidence of dams with fetuses afflicted with teratologic effects of any kind. No significant differences were observed between treated and control animals in the following: maternal mortality, pharmacological examination, food consumption or body weight, live fetuses/dam, average fetal weight, numbers of live litters, implantation sites, resorptions, and dead fetuses.

The mutagenicity of trimethyl phosphite was evaluated in Salmonella tester strains TA98, TA100, TA1535, TA1537 and TA1538 (Ames Test) and in Saccharomyces cerevisiae strain D4, both in the presence and absence of added metabolic activation by Aroclor-induced rat liver S9 fraction. Based on preliminary toxicity determinations, trimethyl phosphite, diluted with DMSO, was tested at concentrations up to 5.0ul/plate using the plate incorporation technique. Trimethyl phosphite did not cause a positive response in any of the tester strains with or without metabolic activation.

The mutagenicity of trimethyl phosphite was evaluated in the germ cells of Drosophila melanogaster by inhalation exposure employing the Y chromosome loss test, dominant lethal test, bithorax test of levels and sex-linked recessive lethal test. Based on preliminary toxicity determinations, trimethyl phosphite, was administered at 10mM to male flies and then mated. Trimethyl phosphite cause a significant increase in genetic damage in the treated Drosophila under the experimental conditions used. Also employed was the white-ivory mosaic test, which did not produce a positive response.

For more TSCA Test Submissions (Complete) data for TRIMETHYL PHOSPHITE (10 total), please visit the HSDB record page.

/EPIDEMIOLOGY STUDIES/ Analyses of workplace air /from a plant engaged in the manufacture of trimethyl phosphite revealed concentrations averaging up to 8 ppm in 1969 and 1971. More thorough studies in this and another facility in 1979 indicated average exposures generally between 0.3 and 4 ppm, with occasional values as high as 15 ppm. Examination of 179 employees in these plants failed to reveal any indications of ocular changes or other adverse effects on worker health associated with occupational exposure to trimethyl phosphite.

/OTHER TOXICITY INFORMATION/ It is only moderately toxic by oral ingestion and an irritant to eyes, skin and upper respiratory system. No information of chronic toxicity of vapors. Exposure of workers during its manufacture and handling may involve low-level inhalation of vapors.

Trimethyl phosphite's production and use as an intermediate, especially for production of pesticides(1), as a fireproofing agent in the production of textiles, as an intermediate in production of flame-retardant polymers for polyurethane foams, and as a catalyst(2) may result in its release to the environment through various waste streams(SRC).

Trimethyl phosphite

80

220

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

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

Plastic Composites Manufacturing [Category: Industry]

Precursor to DMMP /Dimethylmethyl phosphonate/

Trimethyl phosphite has been used primarily as an intermediate in the manufacture of pesticides. It is also used as a fireproofing agent in the production of textiles, as an intermediate in the production of flame-retardant polymers for polyurethane foams, and as a catalyst.

Liquid phosphorus source used in the deposition of phosphosilicate glass (PSG)

Chemical intermediate, especially for insecticides.

2023: 1,000,000 - <5,000,000 lb

(1975) PROBABLY GREATER THAN 1.36X10+6 GRAMS

Phosphorous acid, trimethyl ester is listed as a High Production Volume (HPV) chemical (65FR81686). Chemicals listed as HPV were produced in or imported into the U.S. in >1 million pounds in 1990 and/or 1994. The HPV list is based on the 1990 Inventory Update Rule. (IUR) (40 CFR part 710 subpart B; 51FR21438).

Production volumes for non-confidential chemicals reported under the Inventory Update Rule. [Table#2672]

Non-confidential 2012 Chemical Data Reporting (CDR) information on the production and use of chemicals manufactured or imported into the United States. Chemical: Phosphorous acid, trimethyl ester. National Production Volume: Withheld.

REACTION OF PHOSPHORUS TRICHLORIDE AND METHYL ALCOHOL IN PRESENCE OF A TERTIARY AMINE

Methanol + phosphorus trichloride (dehydrochlorination)

Synthesis: Phosphorus trichloride and methanol. Catalyst: Diethylaniline, petroleum ether.

All Other Basic Organic Chemical Manufacturing

Phosphorous acid, trimethyl ester: ACTIVE

/The Chemical Weapons Convention (CWC) is an international treaty which bans the development, production, stockpiling, and transfer or use of chemical weapons. The Convention mandates the destruction and prohibition of chemical weapons and related facilities and provides for restrictions on international trade in toxic chemicals and precursors./ The Convention's monitoring and verification measures involve submission of declarations regarding ... /Schedule 1, 2, and 3 chemicals/ and inspections by the Organization for the Prohibition of Chemical Weapons of the facilities where these chemicals are produced. ... Schedule 3 chemicals ... /may/ have been stockpiled or used as weapons, but ... are produced /and used/ in large quantities for purposes not prohibited by the Convention (2). Trimethyl phosphite is listed in the CWC Annex on Chemicals under Schedule 3 (1).