Methyl fluoroacetate

1.1744 at 20 °C/4 °C; 1.1613 at 15 °C/4 °C

Density: 1.51 at 15 °C

1.161 @ 15°C

Soluble in water

Slightly soluble in petroleum ether

104.5 °C

104.5 °C @760 [mm Hg]

Danger

H226 (58.3%): Flammable liquid and vapor [Warning Flammable liquids]

P210, P233, P240, P241, P242, P243, P261, P264, P264+P265, P270, P271, P273, P280, P301+P316, P302+P352, P303+P361+P353, P304+P340, P305+P351+P338, P319, P321, P330, P332+P317, P337+P317, P362+P364, P370+P378, P391, P403+P233, P403+P235, P405, and P501 (click each P-code to see the statement)

Aggregated GHS information provided per 96 reports by companies from 6 notifications to the ECHA C&L Inventory. Each notification may be associated with multiple companies.

Gribble GW; J Chem Ed 50 (7): 460-462 (1973); Review[Available from, as of November 16, 2018: http://wadingo.com/1080development.pdf]

Foss GL; Br J Pharmacol Chemother 3 (2): 118-127 (1948)[Available from November 16, 2018: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1509813/]

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.

0.0095 [mg/m3]

0.10 [mg/m3]

0.98 [mg/m3]

TERRESTRIAL FATE: Based on a classification scheme(1), an estimated Koc value of 6(SRC), determined from a structure estimation method(2), indicates that methyl fluoroacetate is expected to have very high mobility in soil(SRC). Volatilization of methyl fluoroacetate from moist soil surfaces is not expected to be an important fate process(SRC) given an estimated Henry's Law constant of 3.5X10-4 atm-cu m/mole(SRC), developed using a fragment constant estimation method(2). Methyl fluoroacetate is expected to volatilize from dry soil surfaces(SRC) based upon an estimated vapor pressure of 31 mm Hg at 25 °C(SRC), determined from a fragment constant method(2). Biodegradation data in soil were not available(SRC, 2018).

AQUATIC FATE: Based on a classification scheme(1), an estimated Koc value of 6(SRC), determined from a structure estimation method(2), indicates that methyl fluoroacetate is not expected to adsorb to suspended solids and sediment(SRC). Volatilization from water surfaces is expected(3) based upon an estimated Henry's Law constant of 3.5X10-4 atm-cu m/mole(SRC), developed using a fragment constant estimation method(2). Using this Henry's Law constant and an estimation method(3), volatilization half-lives for a model river and model lake are 5 hrs and 5 days, respectively(SRC). According to a classification scheme(4), an estimated BCF of 3(SRC), from an estimated log Kow of 0.31(2) and a regression-derived equation(2), suggests the potential for bioconcentration in aquatic organisms is low(SRC). Biodegradation data in water were not available(SRC, 2018).

ATMOSPHERIC FATE: According to a model of gas/particle partitioning of semivolatile organic compounds in the atmosphere(1), methyl fluoroacetate, which has an estimated vapor pressure of 31 mm Hg at 25 °C(SRC), determined from a fragment constant method(2), is expected to exist solely as a vapor in the ambient atmosphere. Vapor-phase methyl fluoroacetate 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 98 days(SRC), calculated from its rate constant of 1.6X10-13 cu cm/molecule-sec at 25 °C(SRC) that was derived using a structure estimation method(2). Methyl fluoroacetate does not contain chromophores that absorb at wavelengths >290 nm(3) and, therefore, is not expected to be susceptible to direct photolysis by sunlight(SRC).

IDENTIFICATION AND USE: Methyl fluoroacetate (MFA) is a mobile liquid. MFA is one of the most potent rodenticides known. However, it presents a high risk of accidental human poisoning. Because of MFA great toxicity, it came into consideration at the start of World War II as a potential warfare agent. HUMAN STUDIES: Nausea and vomiting following ingestion of very small amounts. ANIMAL STUDIES: In most animals it is a convulsant poison and causes progressive depression of respiration. It blocks the enzyme aconitase, thereby inhibiting the TCA cycle. This poison is quick-acting and has no antidote.

Using a structure estimation method based on molecular connectivity indices(1), the Koc of methyl fluoroacetate can be estimated to be 6(SRC). According to a classification scheme(2), this estimated Koc value suggests that methyl fluoroacetate is expected to have very high mobility in soil(SRC).

Methyl fluoroacetate's former production and use as a chemical reagent(1) may result in its release to the environment through various waste streams(SRC); its former use as a rodenticide(2) resulted in its direct release to the environment(SRC).

An estimated BCF of 3 was calculated in fish for methyl fluoroacetate(SRC), using an estimated/ log Kow of 0.31(1) and a regression-derived equation(1). According to a classification scheme(2), this BCF suggests the potential for bioconcentration in aquatic organisms is low(SRC).

The Henry's Law constant for methyl fluoroacetate is estimated as 3.5X10-4 atm-cu m/mole(SRC) developed using a fragment constant estimation method(1). This Henry's Law constant indicates that methyl fluoroacetate is expected to volatilize from water surfaces(2). Based on this Henry's Law constant, the volatilization half-life from a model river (1 m deep, flowing 1 m/sec, wind velocity of 3 m/sec)(2) is estimated as 5 hours(SRC). The volatilization half-life from a model lake (1 m deep, flowing 0.05 m/sec, wind velocity of 0.5 m/sec)(2) is estimated as 5 days(SRC). Methyl fluoroacetate's Henry's Law constant indicates that volatilization from moist soil surfaces may occur(SRC). Methyl fluoroacetate is expected to volatilize from dry soil surfaces(SRC) based upon an estimated vapor pressure of 31 mm Hg(SRC), determined from a fragment constant method(1).

/LABORATORY ANIMALS: Acute Exposure/ Esters of 2-fluoroethyl-fluoroacetate (2-FFA) were prepared in order to determine whether toxicity was related to the presence of two fluorine atoms in the molecule. Toxicity tests were performed in rabbits, guinea-pigs, rats or mice and compared to the toxicity of methyl-fluoroacetate (MFA). The following 2-FFA esters were prepared: 2-chloroethyl-fluoroacetate (2-CFA); 2-fluoroethyl-chloroacetate (2-FCA); 2-fluoroethyl-acetate (2-FA); 2-chloroethyl-fluorothiolacetate; allyl-fluoroacetate (AFA); and phenyl-fluorothiolacetate (PFT). In a concentration of 0.31 mg/L 2-CFA killed 92 percent of the rabbits, guinea-pigs and rats, while 0.10mg/L killed 54 percent. 2-CFA was more toxic than MFA, but not as toxic as 2-FFA. The toxicity of 2-FCA was identical to the toxicity of 2-CFA. The subcutaneous median lethal dose (LD50) of PFT in mice was 80 mg/kg, about 10 percent the toxicity of MFA. The subcutaneous LD50 of 2-CFA was 17.5 mg/kg, less than the toxicity of MFA. By inhalation, AFA was nearly as toxic as MFA, in addition to having an irritant effect. The subcutaneous LD50 of AFA in mice was 6 mg/kg.

/OTHER TOXICITY INFORMATION/ In most animals it is a convulsant poison and causes progressive depression of respiration.

/OTHER TOXICITY INFORMATION/ In a small number of rabbits, dogs, and goats estimations have been made of blood sugar, hemoglobin, plasma proteins, non-protein nitrogen, and serum potassium, calcium chloride, and inorganic phosphate. Apart from the terminal rise in non-protein nitrogen and potassium, blood changes include a rise of 20-60% in Hb, up to 90% in blood sugar, 70-130% in inorganic phosphate and a less significant rise in serum potassium.

The rate constant for the vapor-phase reaction of methyl fluoroacetate with photochemically-produced hydroxyl radicals has been estimated as 1.6X10-13 cu cm/molecule-sec at 25 °C(SRC) using a structure estimation method(1). This corresponds to an atmospheric half-life of about 98 days at an atmospheric concentration of 5X10+5 hydroxyl radicals per cu cm(1). A base-catalyzed second-order hydrolysis rate constant of 2.0 L/mole-sec(SRC) was estimated using a structure estimation method(1); this corresponds to half-lives of 4 days and 10 hours at pH values of 7 and 8, respectively(1). Methyl fluoroacetate does not contain chromophores that absorb at wavelengths >290 nm(2) and, therefore, is not expected to be susceptible to direct photolysis by sunlight(SRC).

Occupational exposure to methyl fluoroacetate may occur through inhalation and dermal contact with this compound at workplaces where methyl fluoroacetate is produced or used. Use data indicate that the general population is not likely to be exposed methyl fluoroacetate. (SRC)

Methyl fluoroacetate's former production and use as a chemical reagent may result in its release to the environment through various waste streams; its former use as a rodenticide resulted in its direct release to the environment. If released to air, an estimated vapor pressure of 31 mm Hg at 25 °C indicates methyl fluoroacetate will exist solely as a vapor in the atmosphere. Vapor-phase methyl fluoroacetate will be degraded in the atmosphere by reaction with photochemically-produced hydroxyl radicals; the half-life for this reaction in air is estimated to be 98 days. Methyl fluoroacetate does not contain chromophores that absorb at wavelengths >290 nm and, therefore, is not expected to be susceptible to direct photolysis by sunlight. If released to soil, methyl fluoroacetate is expected to have very high mobility based upon an estimated Koc of 6. Volatilization from moist soil surfaces is expected to be an important fate process based upon an estimated Henry's Law constant of 3.5X10-4 atm-cu m/mole. Methyl fluoroacetate may volatilize from dry soil surfaces based upon its vapor pressure. Biodegradation data in soil or water were not available. If released into water, methyl fluoroacetate is not expected to adsorb to suspended solids and sediment based upon the estimated Koc. Volatilization from water surfaces is expected to be an important fate process based upon this compound's estimated Henry's Law constant. Estimated volatilization half-lives for a model river and model lake are 5 hours and 5 days, respectively. An estimated BCF of 3 suggests the potential for bioconcentration in aquatic organisms is low. Hydrolysis is expected to be an important environmental fate process as indicated by base-catalyzed half-lives of 4 days and 10 hours at pH values of 7 and 8, respectively. Occupational exposure to methyl fluoroacetate may occur through inhalation and dermal contact with this compound at workplaces where methyl fluoroacetate is produced or used. Use data indicate that the general population is not likely to be exposed to methyl fluoroacetate. (SRC)

/SRP:/ Immediate fist aid: ensure that adequate decontamination has been carried out. If patient is not breathing, start artificial respiration, preferably with a demand-valve resuscitator, bag-valve-mask device, or pocket mask, as trained. Perform CPR as necessary. Immediately flush contaminated eyes with gently flowing water. Do not induce vomiting. If vomiting occurs, lean patient forward or place on left side (head-down position, if possible) to maintain an open airway and prevent aspiration. keep patient quiet and maintain normal body temperature. Obtain medical attention. /Esters and Related compounds/

/SRP:/ Basic treatment: Establish a patent airway. Suction if necessary. Watch for signs of respiratory insufficiency and assist ventilations if necessary. Administer oxygen by nonrebreather mask at 10 to 15 L/min. Monitor for pulmonary edema and treat if necessary ... . Monitor for shock and treat if necessary ... . For eye contamination, flush eyes immediately with water. Irrigate each eye continuously with normal saline during transport ... . Do not use emetics. For ingestion, rinse mouth and administer 5 mL/kg up to 200 mL of water for dilution if the patient can swallow, has a strong gag reflex, and does not drool. Administer activated charcoal ... . /Esters and related compounds/

/SRP:/ Advanced treatment: Consider orotracheal or nasotracheal intubation for airway control in the patient who is unconscious. Positive pressure ventilation techniques with a bag valve mask device may be beneficial. Monitor cardiac rhythm and treat arrhythmias if necessary ... . Start an IV with D5W /SRP: "To keep open", minimal flow rate/. Use lactated Ringer's if signs of hypovolemia are present. Watch for signs of fluid overload. For hypotension with signs of hypovolemia, administer fluid cautiously. Consider vasopressors if patient is hypotensive with a normal fluid volume. Watch for signs of fluid overload ... . Consider drug therapy for pulmonary edema ... . Use proparacaine hydrochloride to assist eye irrigation ... . /Esters and related compounds/

MFA, because of its great toxicity, came into consideration at the start of World War II as a potential warfare agent. MFA seemed especially suitable as a water poison because of its "ideal" physical and chemical properties for this type of agent. In addition, its toxic action is delayed making early detection of MFA in water supplies difficult. By the end of the war several countries including England, the United States, Poland, and Germany had developed efficient pilot-plant methods for the preparation of MFA. /Former use/