Peracetic acid (also known as peroxyacetic acid, or PAA), is an organic compound with the formula CH3CO3H. This organic peroxide is a colorless liquid with a characteristic acrid odor reminiscent of acetic acid. It can be highly corrosive.
Peracetic acid is a weaker acid than the parent acetic acid, with a pKa of 8.2.〔
Peracetic acid is produced industrially by the autoxidation of acetaldehyde:
:O2 + CH3CHO → CH3CO3H
It forms upon treatment of acetic acid with hydrogen peroxide, with the equilibrium constant dependent on the concentrations and conditions of reaction:〔RANGARAJAN, B., HAVEY, A., GRULKE, E. & CULNAN, P. D. 1995. Kinetic parameters of a two-phase model forin situ epoxidation of soybean oil. Journal of the American Oil Chemists’ Society, 72, 1161-1169.
:H2O2 + CH3CO2H CH3CO3H + H2O
As an alternative, acetyl chloride and acetic anhydride can be used to generate a solution of the acid with lower water content.
Peracetic acid is generated in situ by some laundry detergents. This route involves the reaction of tetraacetylethylenediamine (TAED) in the presence of an alkaline hydrogen peroxide solution. The peracetic acid is a more effective bleaching agent than hydrogen peroxide itself.〔United States Department of Agriculture. Agriculture Marketing Service (Peracetic acid ). (PDF document). URL accessed on 11 November 2006.〕 PAA is also formed naturally in the environment through a series of photochemical reactions involving formaldehyde and photo-oxidant radicals.〔U.S. National Library of Medicine. (Hazardous Substances Data Bank ). URL accessed on 11 November 2006.〕
Peracetic acid is always sold in solution with acetic acid and hydrogen peroxide to maintain the stability of the peracid. The concentration of the acid as the active ingredient can vary.
抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』