X-Ray ProcessingX-ray Irradiation Processing

X-ray irradiation is a practical alternative to a variety of other commonly used sterilization and contamination control methods.

The STERIS Applied Sterilization Technologies (AST) X-ray processing site at Däniken, Switzerland uses the Rhodotron Electron beam to generate X-ray. The layout of the plant and manufacturing process is designed to fulfill international standards, including the quality management system standard for medical devices ISO 13485, ISO 11137: Sterilization of Healthcare Products – Radiation, cGMP and FDA guidelines.

What is X-ray?

X-ray-machine-copyThe commercial use of X-ray irradiation began around 20 years ago. However, due to the low power output of the accelerators used, the technology was generally overlooked as a viable sterilization method. Now, with the introduction of high power, high energy accelerators we are able to offer X-ray irradiation technology at a commercial level equivalent to traditional sterilization methods.

A wide variety of healthcare products from implants to pharmaceuticals employ X-ray technology’s sterilizing capability, while industrial applications from semiconductors to micro-etching can benefit from its use. However, the use of X-ray is not restricted to the sterilization of medical devices; pharmaceutical products and decontamination of packaging materials, raw materials for pharmacy and cosmetic businesses are also processed regularly.

Why X-ray Irradiation?

The combination of shorter exposure time and improved dose uniformity ratio (DUR) make X-ray sterilization a viable processing option for a variety of products. Similar to electron beam, X-ray processing is powered by electricity.

  • Due to reduced processing time, lead times are improved whilst maintaining good penetration capability
  • Adverse effects on products are reduced due to the reduction in processing (exposure) time

Benefits of X-ray irradiation Processing


By designing a 2-level conveying system, most of the X-rays are captured by the products. Losses of X-rays are minimized compared with a 1-level conveying system where the products must be over-scanned in order to achieve good Dose Uniformity.


Ability to mix different products with different dose requirements in the same irradiation cycle is possible since the solution is based on an incremental dose concept. One increment consists of four passes of the pallet in front of the X-ray target (pallet irradiated from the top and bottom, front and rear side). The increment dose is the minimum dose the product can receive. Any multiple of the increment dose can be given to the product by adding increments (i.e: if increments have a value of 2.5 kGy, 25 kGy can be given to the product with 10 increments).


Better than Electron beam and similar to Gamma irradiation with less impact on product materials

Processing by X-ray irradiation covers a range of applications from the sterilization of medical devices, sanitization of packaging, cosmetics & toiletries through to polymer modification.

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 Services