What Is Vaporized Hydrogen Peroxide Sterilization?

Hydrogen peroxide has long been used in the healthcare industry, and in the 1970s its vapor form became a low temperature sterilization technique that has only increased in popularity.

In this article, we’ll explain how the hydrogen peroxide sterilization process works, including important federal guidelines to be aware of and potential challenges.

What Is Low Temperature Sterilization?

Low temperature sterilization refers to a type of sterilization process using gas or certain types of chemicals for items that cannot be processed using steam. Ethylene oxide used to be the main form of low temperature sterilization, but it is a slow process and subject to regulatory hurdles as evidence points toward an increased risk of certain cancers with long-term exposure.

As a result, hydrogen peroxide has largely replaced the use of ethylene oxide.

What Is Hydrogen Peroxide Sterilization?

Also known as vaporized hydrogen peroxide sterilization, this refers to a process used to sterilize heat-sensitive devices or materials, such as some types of plastics, electrical devices and corrosion-susceptible metal alloys. Hydrogen peroxide sterilization, which is non-toxic (since only water vapor and oxygen are produced), is used for medical implants, electronic devices and temperature-sensitive devices.

This type of sterilization is also compatible with a variety of materials, including polypropylene, brass and polyethylene, but it should not be used to process linens, powders, liquids or cellulose material.

Though it initially presented market and material issues, many of these have been resolved, making it the dominant method for low temperature sterilization. There are a number of different vapor hydrogen peroxide sterilizer manufacturers; their processes — including those that use gas plasma or ozone as part of the sterilization cycle — are, as far as hospitals are concerned, essentially equivalent and aimed at low temperature sterilization. Neither gas plasma nor ozone contribute to the sterilization of the products but instead are present to help destroy residual hydrogen peroxide.

The Hydrogen Peroxide Sterilization Process

A solution with water and a high concentration of hydrogen peroxide is converted into gas, which is then circulated at certain concentrations throughout the chamber. After the process is complete, the vapor is vacuumed out of the chamber and converted into water and oxygen.

The temperature range for this process is 37–44°C with a sterilization cycle time of around 75 minutes.

Hydrogen Peroxide Sterilization Guidelines

The U.S. Food & Drug Administration, the International Organization for Standardization and the Centers for Disease Control & Prevention (CDC) provide federal guidelines and recommendations for all types of sterilization.

For example, high-level hydrogen peroxide sterilization for lensed medical instruments requires an exposure time of 12–30 minutes at a temperature greater than or equal to 20°C with 7.5% hydrogen peroxide.

There are also hydrogen peroxide exposure limits established by OSHA.

Challenges With Hydrogen Peroxide Sterilization

While vaporized hydrogen peroxide sterilization is common, there are some challenges.

1. The sterilization chamber is often smaller than a steam autoclave, and there may be load limits based on the design and manufacturer.
2. Some materials may not be compatible with VHP sterilization due to their sensitivity to moisture or oxidizing agents. It is important to validate the compatibility of materials before using a VHP process.
3. VHP requires precise control of several parameters, including temperature, humidity, and exposure time. Any deviation from the optimal conditions can affect the effectiveness of the sterilization process.
4. VHP can leave residual hydrogen peroxide on surfaces, which may affect product quality. Therefore, it is essential to perform adequate post-sterilization cycles to remove any residuals.

When it comes to sterilization, there are a variety of options, some of which are more effective than others. While vaporized hydrogen peroxide has become the most popular choice for heat-sensitive items, steam sterilization — which is faster, more effective and less expensive than hydrogen peroxide — is an ideal choice for sterilizing all other types of medical equipment.

We invite you to take our free self-assessment to see whether your current sterilization setup sufficiently meets your team’s needs, and then contact the team at CSS with any questions.