Apparatus for plasma sterilizing with pulsed antimicrobial agent

Abstract

A process and equipment for plasma sterilization in which articles in a sterilizing chamber are taken through at least one combination sterilizing cycle. The articles to be sterilized may include the interior of a vessel or chamber. In that case, the vessel or chamber itself may serve as a sterilizing chamber and connects to the plasma generating chamber. Each combination sterilizing cycle includes a pulsed treatment with gaseous antimicrobial agent, removal of the gaseous antimicrobial agent, and a plasma treatment. The pulsed treatment includes one or more pulse-vacuum cycles, each pulse-vacuum cycle includes the steps of evacuating the sterilizing chamber and exposing the article to the gaseous antimicrobial agent with a predetermined pressure profile during a predetermined time. The gaseous antimicrobial agent is preferably carried in a gas mixture with a nonreactive carrier gas. In one embodiment, the predetermined pressure is pulsed. In another embodiment, it is ramped. After the pulsed treatment, the antimicrobial agent is removed by evacuating the sterilizing chamber. The plasma treatment includes exposure of the article to a plasma having essentially uncharged, highly reactive free radicals, molecules and atoms.