Peracetic acid is a highly biocidal oxidizer that maintains its efficacy in the presence of organic soil. Peracetic acid removes surface contaminants (primarily protein) on endoscopic tubing. An automated machine uses peracetic acid to sterilize medical, surgical, and dental instruments chemically (endoscopes, arthroscopes). Introduced in 1988, this microprocessor-controlled, low-temperature sterilization method is commonly used in the United States.
The sterilant, 35% peracetic acid, and an anticorrosive agent are supplied in a single-dose container. The concentrated peracetic acid is diluted to 0.2% with filtered water at a temperature of approximately 122°F. The diluted peracetic acid is circulated within the chamber of the machine and pumped through the channels of the endoscope for 12 minutes, decontaminating exterior surfaces, lumens, and accessories. The peracetic acid is discarded via the sewer and the instrument rinsed four times with filtered water.
Limited information is available regarding the mechanism of action of peracetic acid, but it is thought to function like other oxidizing agents, i.e., it denatures proteins, disrupts cell wall permeability, and oxidizes sulfhydral and sulfur bonds in proteins, enzymes, and other metabolites.
Peracetic acid will inactivate gram-positive and gram-negative bacteria, fungi, and yeasts in less than 5 minutes at <100 ppm. In the presence of organic matter, 200-500 ppm is required. For viruses, the amount required is a wide range (12-2250 ppm), with poliovirus inactivated in yeast extract in 15 minutes with 1500 to 2250 ppm. Bacterial spores in suspension
