Peracetic acid (also known as peroxyacetic acid, or PAA), is an organic compound. It is a colorless liquid with a characteristic pungent odor reminiscent of household vinegar. All commercially available PAA products contain an equilibrium of PAA, hydrogen peroxide, acetic acid, and water. Its formula is CH3CO3H.
Peracetic acid is an ideal antimicrobial agent due to its high oxidizing potential. It is highly effective against a broad range of microorganisms. In addition, PAA breaks down in food to safe and environmentally friendly residues (acetic acid and hydrogen peroxide), and therefore can be used in non-rinse applications. PAA is one of the most environmentally friendly antimicrobial agents, since resulting wastewater can be land-applied for irrigation and is generally eligible for NPDES permits to discharge to natural waterways.
The United States Environmental Protection Agency first registered peracetic acid as an antimicrobial in 1985 for indoor use on hard surfaces. Today, registered applications have expanded to include: sanitation at food and beverage plants, agricultural premises, wineries and breweries, greenhouse facilities and equipment, as well as animal housing. Peracetic acid is also approved for use in dairy/cheese processing plants, and directly on fruits and vegetables, as well as on meat, poultry, and seafood products. It is also used to prevent bio film formation in paper and pulp industries, and as a disinfectant for municipal effluent. As the interest in “green chemistries” increases, PAA is finding use as a biocide in industrial cooling water systems.