Peracetic acid

Peracetic acid (PAA, CAS 79-21-0) is an organic peroxide formed by the reaction of acetic acid and hydrogen peroxide. It is also known as peroxyacetic acid, peroxoacetic acid, and acetic peroxide, and sold under trade names including Osbon AC and Desoxon 1. It carries no assigned E-code and is not used as a direct food additive.

In water treatment and food processing, PAA acts as a disinfectant by releasing reactive oxygen species that disrupt microbial cell membranes, achieving broad-spectrum kill against bacteria, yeasts, and biofilms at low concentrations. In pulp and paper production, it functions as a bleaching agent by oxidising chromophoric lignin structures without generating chlorinated by-products.

Peracetic acid is supplied in aqueous solution at concentrations typically ranging from 5% to 40%, stabilised with acetic acid and hydrogen peroxide. Grades are available to meet food-contact and pharmaceutical requirements under REACH registration. Packaging is commonly in IBC containers and drums, with ADR classification applying due to oxidising and corrosive properties.