Vaporized Hydrogen Peroxide Gas Plasma Technology Explained

Advances in technology transformed many aspects of medicine such as robotic-assisted procedures in the modern world that lead to more complex surgical instruments. This posed challenges for sterilization using the traditional steam autoclave, and it paved the way for the development of other sterilization modality to process delicate instrumentation such as flexible endoscopes.

While Ethylene Oxide (EtO) was introduced as an alternative to steam sterilization for the sterilization of heat and moisture-sensitive instruments, there are many disadvantages associated with the use of EtO such as long sterilization cycles, cost and potential hazards to patient and staff.1

Innovation of Low Temperature Sterilization

A group of scientists from a company in Texas pioneered the novel idea of using hydrogen peroxide for device sterilization. In 1987, this company officially formed as Advanced Sterilization Products (ASP).

ASP’s first vaporized hydrogen peroxide gas plasma sterilizer, the STERRAD™ 100 System received FDA clearance in 1993. This first-of-its-kind technology sterilizes medical devices by diffusing hydrogen peroxide vapor into the chamber and then electromagnetically exciting the hydrogen peroxide molecules into a low-temperature plasma state. The combined use of hydrogen peroxide vapor and plasma safely and rapidly sterilizes medical instruments and materials without leaving toxic residue.

ASP continues to innovate, introducing other sterilization systems such as the STERRAD NX™ System in 2005 and STERRAD™ 100NX System in 2007.


Exclusive Technology Unique to STERRAD™ Systems

STERRAD™ System continues to be the market leader in low-temperature sterilization, trusted by healthcare institutions around the world to terminally sterilize instruments. Features of STERRAD™ Systems are not superfluous; rather each were deliberate and intentional to directly address challenges that may occur in real-world reprocessing.

Three Pillars of STERRAD™ System


Hydrogen Peroxide Monitoring

Gas Plasma

Hydrogen Peroxide Monitoring

Gas Plasma


STERRAD™ Systems with
ALLClear™ Technology

STERRAD™ Systems with
ALLClear™ Technology


ASP ACCESS™ Technology

ASP ACCESS™ Technology

Enhanced safety

Hydrogen Peroxide Monitoring

Hydrogen peroxide monitoring in the STERRAD NX™ Sterilizer and STERRAD™ 100NX Sterilizer ensures concentration levels of hydrogen peroxide are maintained during the exposure period for effective microbicidal activity. The STERRAD NX™ Sterilizer and STERRAD™ 100NX Sterilizer feature a control system with a fully integrated hydrogen peroxide monitor as a standard equipment for direct measurement of the chamber sterilant concentration. The hydrogen peroxide monitor provides data to the process controller which uses this data and information on acceptable cycle limits determined by statistical analysis of microbiological efficacy testing to make decisions regarding the acceptability of each cycle and ensure a minimum sterility assurance level (SAL) of 10-6.

STERRAD™ System’s built-in continuous hydrogen peroxide monitor consists of a UV light source and detector that senses fluctuations in the interaction between the hydrogen peroxide vapor and UV light intensity. When the concentration of hydrogen peroxide drops below a defined threshold for effective sterilization, the UV light intensity changes, signaling the system to abort the sterilization cycle.

Gas Plasma

STERRAD™ Systems, also referred to as Vaporized Hydrogen Peroxide Gas Plasma Sterilization, utilize an exclusive gas plasma technology to directly remove hydrogen peroxide residual from the chamber and instruments. Once hydrogen peroxide diffuses through the chamber and surrounds the instrument in the load, the low-temperature gas plasma is ignited by applying an electric field. Plasma causes the hydrogen peroxide vapor to break apart into free radicals. When plasma energy is terminated, the free radicals lose their high energy state and recombine as oxygen and water vapor.


STERRAD™ Systems minimize healthcare worker exposure to hydrogen peroxide when opening the sterilizer door after a completed cycle and emits significantly less hydrogen peroxide than STERIS® VPRO-Sterilizers.

In a side-by-side comparative study2, continuous hydrogen peroxide emissions monitoring of STERRAD™ Systems and STERIS® V-PRO® Sterilizers resulted with V-PRO® Sterilizers emissions registering 67 times higher than those of STERRAD™ Systems when opening the sterilizer door after a cycle. The results of the study demonstrate that STERRAD™ Systems which uses a gas plasma phase to dissociate hydrogen peroxide during the sterilization cycle, is more effective in limiting hydrogen peroxides than the STERIS® V-PRO® maX, which only passes hydrogen peroxide through a catalytic converter.

Increased efficiency

STERRAD™ System with ALLClear™ Technology

STERRAD™System with ALLClear™ Technology found in the STERRAD NX™ System and STERRAD™ 100NX System sterilizers is an automatic pre-cycle system diagnosis and load condition technology that minimizes cancelled cycles. STERRAD™ System with ALLClear™ Technology can detect load issues such as excessive moisture faster3 and is more intelligent with load conditioning4 than the STERIS® V-PRO® maX sterilizer.

According to a Market Survey5, 100% of customers agree that the STERRAD™ System with ALLClear™ Technology are easy to use and 80% of customers agree that the systems reduce operator error as compared to the legacy STERRAD™ 100NX System and STERRAD NX™ Systems.


ASP ACCESS™ Technology

ASP ACCESS™ Technology is a smart information-sharing technology that links ASP devices with hospital networks including instrument tracking systems (ITS). ASP technologies now can work together to help reduce human errors. On-screen, step-by-step instructions with automatic checkpoints help ensure compliance with Instructions for Use (IFU) and hospital policies.

ASP is committed to continuously advancing infection prevention technologies

ASP has a rich history of innovation in sterilization designed to ensure focus on our highest priority: keeping patients safe.

To learn more about STERRAD™ System’s exclusive safety features or get a consultation from one of our experts, please contact ASP today.


  1. Centers for Disease Control and Prevention (CDC). Guideline for Disinfection and Sterilization in Healthcare Facilities (2008). Ethylene Oxide “Gas” Sterilization. Accessed September 5, 2020

  2. The research was designed and executed by Actionable Research, an independent third-party research firm in conjunction with ChemDAQ® Inc., a manufacturer of environmental safety monitoring systems. The research sponsor was Advanced Sterilization Products. All data were collected by the ChemDAQ® staff.

  3. For non-lumen and flex cycles

  4. In STERRAD™ Systems with ALLClea™ Technology, cancellations occur before the sterilization cycle begins if the load is not optimal for sterilization

  5. Based on market survey conducted by Advanced Sterilization Products

The third-party trademarks used herein are the properties of their respective owners. Important information: Prior to use, refer to the instructions for use supplied with this device for indications, contraindications, warnings and precautions.