X-Ray ProcessingX-ray Irradiation Processing

The X-ray irradiation process utilizes photon radiation for a variety of applications, including sterilization, decontamination and materials modification. The X-ray process is compatible with most materials and provides excellent penetration on dense products.

What is X-ray Irradiation?

X-ray-machine-copyX-ray starts as an electron beam where electrons are generated and accelerated to gain energy. Electrons are generated in equipment with an energy of 5 to 7.5 MeV (million electron volts) and at a high power in the hundreds of kW (kilowatts). The electrons are then focused on a specific metal target of high atomic number. The X-ray radiation is generated through a process called Bremsstrahlung to create electromagnetic energy (photons) with an energy in the same range as gamma.

What is X-ray Irradiation Used for?

X-ray irradiation can effectively treat a wide variety of materials with varying densities, configurations and orientations. Some examples of types of products processed include:

  • Medical devices
  • Pharmaceuticals
  • Combination drug/device products
  • Tissue-based and biological products
  • Animal retail products
  • Archives
  • Cosmetics and toiletries
  • Horticultural supplies
  • Packaging materials

What are the Benefits of X-ray Irradiation Processing?

X-ray irradiation is safe, reliable and highly effective at treating a wide variety of products with varying densities. The combination of shorter exposure time and improved Dose Uniformity Ratio (DUR) make X-ray irradiation a viable processing option for a variety of products. Similar to electron beam, X-ray processing is powered by electricity. Benefits of X-ray include:

  • Improved penetration ability of photon energy, similar to gamma
  • Fast and efficient targeted processing that facilitates scale from carton to full pallets of product
  • Flexibility – ability to mix different products with different dose requirements in the same irradiation cycle
  • Reduced material degradation with reduced processing times and reduce of the maximal dose given to product in comparison to Gamma and E-beam irradiation.
  • Ability to process to tight dose specifications through improved DUR
  • Incremental lap-based dose delivery, offering flexible and precise process definition across a wide range of doses


X-ray sterilization is supported by the internationally recognized consensus standard, ISO 11137, which describes the approach to validating a dose to achieve a defined sterility assurance level (SAL).

X-ray Irradiation Support Services:

In addition to irradiation sterilization, STERIS AST provides our Customers with laboratory testing and technical support solutions at every stage of the sterilization design process, from product development through routine processing.

Our Radiation TechTeam® guides Customers through the irradiation validation process, provides solutions for unique project needs, and supports routine processing through quarterly dose audits.

The Radiation Technology Center (RTC) supports our Customers with radiation test activities such as product trials, dose establishment and dose verification. The RTC provides high-precision dose delivery for validation, dose mapping, dose audit, and research purposes.

Our testing services provide Customers with validation support and microbial testing of their products proceed with irradiation. As part of our complete radiation validation program, we will develop a protocol, assemble all testing and validation data, summarize results and make recommendations based on your product, as well as provide on-going support through a dedicated Radiation TechTeam Project Manager. Go here to learn more about our testing services available.

X-ray Irradiation Summary


X-ray irradiation uses ionizing energy from high-powered electron beam accelerators

Technology Variables

  • Processing Speed
  • Number of Passes
  • Product Conveyance

Product Considerations

    • Compatible with most materials
    • Excellent penetration on dense products

Possible Effects


Similar to gamma, but less pronounced due to improved dose uniformity and processing time

Exposure Time


    • (time varies based on dose requirements)


As a global leading sterilization and decontamination specialist, STERIS AST has over 40 years experience in providing safe and effective irradiation sterilization.

Contact our team of experts to find out more about our Global Contract Sterilization, Testing and Validation Services.