Written and maintained by CASRAI Editorial Board
Last updated
Short answer
Sterilization technology is the set of processes that make a product free of viable microorganisms. FDA lists moist heat (steam), dry heat, radiation, ethylene oxide (EtO) gas and vaporized hydrogen peroxide as the main methods for medical devices. CDC names steam as the recommended process for heat- and moisture-resistant items, and points to low-temperature technologies for items that cannot take heat or moisture.
What sterilization technology covers
The term covers the processes, equipment and standards used to sterilize reusable instruments in clinics and laboratories and single-use products before they ship. CDC’s Guideline for Disinfection and Sterilization in Healthcare Facilities ties the need for sterility to the item’s use: critical items, which contact sterile tissue or fluids (surgical instruments, biopsy forceps, implants), “should be sterile when used”. CDC adds that inadequately sterilized critical items carry a high risk of transmitting pathogens, although documented transmission is exceedingly rare.
Sterilization is a different outcome from disinfection. For the lower-level processes and how items are classified by use, see high-level disinfection and the Spaulding classification.
How the main methods work in practice
Steam (moist heat)
CDC calls steam “the recommended sterilization process” for heat-resistant items because it has the largest margin of safety. For wrapped healthcare supplies, CDC’s steam sterilization page gives minimum exposures of 30 minutes at 121°C (250°F) in a gravity displacement sterilizer and 4 minutes at 132°C (270°F) in a prevacuum sterilizer. The biological indicator is spores of Geobacillus stearothermophilus. Steam can damage some materials: CDC cites corrosion and combustion of lubricants on dental handpieces, reduced light transmission in laryngoscopes, and longer plaster-cast hardening time. Equipment background is in what is an autoclave.
Ethylene oxide gas
CDC notes EtO has been used since the 1950s for heat- and moisture-sensitive medical devices. FDA calls it an important method that manufacturers widely use and says that for many medical devices it may be the only method that effectively sterilizes without damaging the device. FDA also states that long-term and occupational exposure to ethylene oxide has been linked to cancer.
Radiation
For 510(k)-cleared devices, FDA describes radiation as an established Category A sterilization method. The FDA page names AAMI TIR104:2022, which covers transferring products between radiation sources.
Vaporized hydrogen peroxide and other low-temperature processes
FDA now considers vaporized hydrogen peroxide (VH2O2) an established Category A process and names ISO 22441:2022 for low-temperature vaporized hydrogen peroxide sterilization of health care products. CDC lists hydrogen peroxide gas plasma, peracetic acid immersion and ozone as low-temperature technologies for heat- or moisture-sensitive items. For choosing among EtO, VHP and ozone, see low-temperature sterilization method selection.
Dry heat
FDA includes dry heat in its list of sterilization methods for medical devices. For a lab-equipment comparison with steam, see dry heat sterilizer vs autoclave.
Methods compared: what the regulators and standards say
This cross-walk puts FDA’s method list, CDC’s guidance and the standards FDA names side by side.
| Method | FDA | CDC | Standard named by FDA |
|---|---|---|---|
| Steam (moist heat) | Listed method | Recommended for heat- and moisture-resistant items; largest margin of safety | |
| Dry heat | Listed method | ||
| Radiation | Established Category A (for 510(k)-cleared devices) | AAMI TIR104:2022 (transfer between radiation sources) | |
| Ethylene oxide | Listed method; widely used | In use since the 1950s for heat- and moisture-sensitive devices | ANSI/AAMI/ISO 11135:2014; ANSI/AAMI/ISO 10993-7:2008(R)2012 (EtO residuals) |
| Vaporized hydrogen peroxide | Established Category A | Hydrogen peroxide gas plasma listed as a low-temperature technology | ISO 22441:2022 |
FDA sorts methods into Established Category A, Established Category B and Novel. FDA also names AAMI TIR17 on the compatibility of materials subjected to sterilization, which is the document to consult when a device material may not tolerate a method.
Where it matters for labs, clinics and supply decisions
- Heat-resistant versus heat- or moisture-sensitive items. CDC’s logic starts here: steam where the item allows it, a low-temperature technology where it does not.
- Material compatibility. CDC’s steam examples (handpiece lubricants, laryngoscope light transmission) show why an item’s own instructions decide the method. Standards such as AAMI TIR17 address compatibility.
- EtO exposure. FDA states that long-term and occupational exposure has been linked to cancer, so exposure is part of any decision to use EtO.
- Proof that a cycle worked. Process validation is a separate discipline; see sterilization validation.
Common misunderstandings
“A sterility assurance level of 10-6 is universal.”
CDC defines sterility assurance level (SAL) as the probability of a single viable microorganism occurring on a product after sterilization, normally expressed as 10-n. CDC reports that dual SALs have been used in the United States for many years: 10-3 for items such as blood culture tubes and drainage bags, and 10-6 for scalpels and implants. CDC also says the choice of 10-6 was “strictly arbitrary and not associated with any adverse outcomes”. More in sterility assurance level.
“All methods are interchangeable.”
FDA’s EtO statement shows otherwise: for many devices, EtO may be the only method that sterilizes without damaging the device. CDC’s steam examples show that even the recommended process can damage particular materials.
“Ultraviolet light is another sterilization method.”
FDA’s list of sterilization methods for medical devices does not name ultraviolet light. CDC and FDA guidance on sterilization centers on the methods above.
Frequently asked questions
What are the main sterilization methods for medical devices?
FDA lists moist heat (steam), dry heat, radiation, ethylene oxide gas and vaporized hydrogen peroxide, along with other methods.
Which sterilization method is recommended for heat-resistant items?
CDC calls steam sterilization the recommended process for heat-resistant items because it has the largest margin of safety.
What can be used for items that cannot take heat or moisture?
CDC gives hydrogen peroxide gas plasma, peracetic acid immersion and ozone as low-temperature examples, and notes that ethylene oxide gas has been used since the 1950s for heat- and moisture-sensitive devices.
Is a sterility assurance level of 10-6 required for every product?
No. CDC reports that dual SALs have been used in the United States: 10-3 for items such as blood culture tubes and 10-6 for scalpels and implants.
Sources
- U.S. FDA, Sterilization for Medical Devices (content current as of 05/14/2025; checked 2026-10-29).
- CDC, Sterilization, from the Guideline for Disinfection and Sterilization in Healthcare Facilities (2008; page dated November 28, 2023; checked 2026-10-29).
- CDC, Steam Sterilization (page dated November 28, 2023; checked 2026-10-29).
