Differences in Liquid vs. Vaporized Peracetic Acid

  • Posted on: 6 July 2016
  • By: REVOX Steriliza...

Because REVOX room-temperature sterilization is a recent innovation in industrial disinfection, medical manufacturers are often curious about how vaporized peracetic acid (VPA) could be used in the process without damaging their products. REVOX co-inventor Mason Schwartz says he occasionally encounters some initial misunderstandings about the chemical reaction, and he notes that it’s crucial to differentiate liquid PA from vaporized PA, which is used in the REVOX process.

“Some people look at the material compatibility with liquid PA and draw a parallel between that and VPA and say, ‘Well, they must be equivalent,’ but they’re not,” he explains. “The liquid version, we’ve found, is more corrosive than the vapor version by a pretty significant margin.”

Peracetic acid is a highly effective chemical sterilant, but by using it in a vaporized form, the REVOX method can easily disinfect products safely that could normally be damaged by a liquid chemical or by moisture and heat. The REVOX process works by vaporizing a proprietary PA sterilant as it is injected into the chamber. At the same time, it raises the internal pressure surrounding the product to be sterilized. After the VPA is allowed to “dwell” and stay in contact with the product for a sufficient amount of time to thoroughly kill all contaminating microbes, the chamber dehumidification and ventilation phase cleanly extracts the chemical vapor, leaving zero residuals. And because the process runs at room temperature, harmful chemical reactions that could occur with heat are prevented.

Using a VPA--based sterilization method provides a significant advantage in terms of material compatibility, Schwartz notes. “Copper, for example, corrodes pretty aggressively with liquid PA but is not harmed by the vapor. Some others that are more compatible with VPA sterilization are polystyrene materials,” he says. In addition, Schwartz points out the REVOX process can safely sterilize polyacetals and elastomers, or elastic polymers such as synthetic rubber. “Even in the elastomers we see better material compatibility in the vapor form than we do with the liquid form.”

In effect, REVOX VPA ensures that a much broader variety of products can be safely and efficiently sterilized.  For a list of other materials tested: Materials Compatibility List