Fluoroacetic acid

Fluoroacetic acid, also known as fluoroacetate, is a toxic organofluorine compound with the chemical formula CH2FCOOH. It is one of the strongest known inhibitors of the tricarboxylic acid cycle (also known as the Krebs cycle or citric acid cycle), which is a crucial part of cellular respiration. Due to its potent toxicity, fluoroacetic acid is classified as a pesticide and has been used in pest control, particularly in the eradication of invasive species. However, its use is highly regulated due to the potential for environmental harm and the risk it poses to non-target species, including humans.

Chemistry

Fluoroacetic acid is structurally similar to acetic acid, with a fluorine atom replacing one of the hydrogen atoms in the methyl group. This substitution greatly affects the biological activity of the compound, making it significantly more toxic. Fluoroacetic acid is a colorless liquid under standard conditions and is soluble in water and organic solvents.

Mechanism of Action

The primary mechanism of toxicity of fluoroacetic acid involves its conversion to fluoroacetyl-CoA by the enzyme acetyl-CoA synthetase. Fluoroacetyl-CoA then condenses with oxaloacetate to form fluorocitrate, an analog of citrate, by the enzyme citrate synthase. Fluorocitrate is a potent inhibitor of aconitase, an essential enzyme in the tricarboxylic acid cycle. This inhibition disrupts the cycle, preventing cells from generating ATP, which leads to energy depletion and ultimately cell death.

Toxicology

Fluoroacetic acid is highly toxic to all aerobic organisms, including mammals, birds, fish, and insects. The symptoms of poisoning can vary among species but generally include convulsions, respiratory failure, and cardiac arrest, leading to death. The lethal dose for humans is estimated to be between 2 to 10 mg/kg of body weight. There is no known antidote for fluoroacetate poisoning, making exposure to this compound particularly dangerous.

Environmental Impact

The use of fluoroacetic acid as a pesticide has raised significant environmental concerns. It can persist in soil and water, leading to accidental poisoning of non-target species, including endangered wildlife and domestic animals. Its persistence also raises the potential for bioaccumulation and biomagnification in food chains, posing long-term ecological risks.

Regulation and Control

Due to its high toxicity and environmental impact, the use of fluoroacetic acid is strictly regulated in many countries. Its application is generally limited to bait products for controlling specific invasive species in designated areas. Management strategies focus on minimizing non-target exposure and include the use of bait stations and warning signs in treated areas.

See Also

• Pesticide
• Tricarboxylic acid cycle
• Acetic acid
• Environmental toxicology

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