trichloroacetic

Trichloroacetic acid, commonly abbreviated as TCA, is a halogenated carboxylic acid with the chemical formula C2HCl3O2 (often written as CCl3CO2H). It is a strong organic acid, considerably more acidic than acetic acid, with a pKa around 0.65. At room temperature it typically presents as a white, crystalline solid and is highly soluble in water as well as many organic solvents. Its melting point is about 60–61°C.

Commercially, trichloroacetic acid is produced by controlled chlorination of acetic acid, followed by purification to separate the desired trichloro derivative from other chlorinated acetic acids. The process is conducted under conditions that manage corrosivity and byproduct formation.

Uses of trichloroacetic acid span organic synthesis, biochemistry, and medicine. In the laboratory it serves as a versatile reagent for acylation and other transformations. In biochemistry and molecular biology, it is widely used to precipitate proteins from solution, enabling sample cleanup and concentration. Dermatologically, TCA is employed in chemical peels at controlled concentrations (commonly in the range of 10–35%) to induce controlled epidermal exfoliation under professional supervision.

Safety and handling are important due to its corrosivity and irritant properties. Concentrated TCA can cause severe skin and eye burns and respiratory irritation if inhaled. It should be stored and used with appropriate personal protective equipment, away from incompatible bases and oxidizers. Environmental exposure should be minimized, as with many halogenated organic acids.