ABSTRACT Peracetic acid, CH3COOOH, is a relatively stable and highly potent bactericide which decomposes to acetic acid, oxygen and water. Although these qualities indicate that peracetic acid (PAA) should be useful as a germicide for the food industries, few investigators have examined the practical applications of PAA in food processing. Hutchings and Xezones (1949) and Gershenfeld and Davis (1952) reported that PAA was an effective bactericide for food plant sanitation. The former investigators found PAA to be more effective than the twenty-five quaternaries, chlorine-containing compounds and proprietary cleaners evaluated for bactericidal action. Greenspan and collaborators (1950 (1951) described large-scale field tests where PAA was found to retard mold growth on tomatoes and grapes over two to three day holding periods. The F.D.A. had not objected to use of PAA as a germicidal wash for tomatoes where a water-wash step precedes processing (Greenspan, 1955). Cotterill and Hartman (1955) found that PAA lacked . . .