Cherwell Range Supports Users of VHP Sterilization
15 Aug 2012

Cherwell Laboratories has tailored a range of products for validating Vaporized Hydrogen Peroxide (VHP) sterilization. VHP sterilization is used as a surface sterilizing agent in an increasing range of applications. For example, in the pharmaceutical, medical device and healthcare industries VHP is used to protect critical processes by surface sterilizing components and consumable packaging in isolators and Restricted Access Barrier Systems (RABS). It is an essential requirement for Good Manufacturing Practice (GMP) that the disinfection process is validated and that any enclosed environment is monitored for microbiological contamination.

Cherwell Laboratories has been supplying active air samplers and Redipor® culture media, gamma irradiated settle plates and contact plates, for environmental monitoring for over 20 years. In response to increasing use of VHP decontamination methods, this equipment has been successfully adapted to be used with hydrogen peroxide vapor systems.

The SAS air sampler range includes models that can remain permanently in the isolator and be sanitized in place with hydrogen peroxide. Barrier Pack, gas impermeable packaging for the Redipor® range of prepared microbiological media, enables agar plates to be presented in packs where the inner layer is impermeable to the vapor therefore protecting the agar medium during gassing.

A range of spore suspensions and specialist biological indicators developed by Apex Laboratories for monitoring vaporized hydrogen peroxide sterilization are also available from Cherwell. As VHP sterilization at ambient pressure works on surfaces but does not penetrate well, validation of the process presents unique challenges. The biological indicators used to validate hydrogen peroxide sterilization must therefore present a sufficient population, greater than 1 x 106, as a monolayer on a clean, smooth stainless steel surface. Apex biological indicators have been developed so the envelope in which they are presented protects the biological indicator, whilst allowing the hydrogen peroxide to penetrate.

Cherwell Laboratories, in conjunction with their specialist suppliers, also offers customers application advice and technical support on the validation of VHP sterilization. VHP has not been used as extensively as steam, dry heat or EtO (ethylene oxide) sterilization and there is no standard set of conditions for its use.

“We pride ourselves on our access to a wealth of expertise in VHP monitoring which can be passed on to our customers in order to optimize their sterilization and decontamination processes,” said Andrew Barrow, Sales Manager at Cherwell Laboratories. “A good example of this is a recent newsletter from Mesa Labs, our supplier for biological indicators, which presents some interesting results on the response of biological indicators to hydrogen peroxide vapor.”

Request Info


Company website

Cherwell Laboratories Ltd