Trichloroacetic acid general information, toxicity, formulations and histology

Trichloroacetic acid general information, toxicity, formulations and histology 

General chemical structure of a haloacetic acid, a indicates the alpha carbon atom. X, Y and Z represent hydrogen (H) or a halogen (F, Cl, Br or I) - at least one of these must be a halogen. 

In both its acid form and its salt forms (e.g. sodium monochloroacetate), MCA is highly toxic to the skeletal muscles, the renal system and cardiovascular system and is rapidly absorbed through the skin and mucous membranes. 

MCA poisoning by ingestion, inhalation or exposure of more than 5% of the body surface area is frequently lethal. The symptoms of poisoning are not immediate they can appear between 1 and 4 hours after exposure. The non-corrosive sodium salt does not penetrate the skin and is not toxic by skin contact (unlike MCA, which passes through the skin very easily). It is, on the other hand, highly toxic by the oral route. There are no data available on the parenteral administration of MCA in humans. In laboratory animals. 

The mechanism of MCA toxicity seems to be via inhibition of the enzyme pyruvate dehydrogenase this inhibition blocks the Krebs (tricarboxylic acid) cycle and disrupts the cell s energy supply. Almost immediately, the cell finds itself without energy. Ketoglutarate dehydrogenase activity is also reduced, which causes lactic acidosis. The MCA also damages the blood-brain barrier, probably through the formation of vascular endothelial microlesions. 

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