Radiation sterilization

atomic structure

Sterilization of medical equipment is one of the most important challenges in the country’s healthcare field. In this regard, the use of electron beam irradiation technology has been proposed as one of the effective and safe methods for sterilizing medical equipment. Sterilization by electron beam has been proposed as an advanced, novel, and growing process, and in this article, we will examine the principles, advantages, and challenges related to this technology.

Sterilization by radiation

Atom is the smallest particle that makes up matter and is made up of smaller particles such as protons, neutrons, and electrons. If in any way, for example, by applying kinetic energy, we can stimulate an atom and take it out of its stable state, the atom will try to return itself to its stable state. One of the most important things an atom can do is release its excess energy in the form of radiation.

In physics, radiation is the release or transfer of energy in the form of waves or particles in space or a material medium. Radiation can be emitted as waves or particles. The types of rays that are emitted in the form of particles from their sources include alpha, beta, and neutrons, and the types that are emitted in the form of waves include gamma rays, X-rays, etc. These rays can be used for disease diagnosis and treatment, imaging, and sterilization.

sterilization by radiation

Ionizing and non-ionizing waves

Waves that have a high frequency and energy can separate the electrons of the atom and charge it when they collide with the atoms. For this reason, these waves are called ionizing waves. Alpha, beta, X-rays, and gamma rays are ionizing forms of electromagnetic waves.

Non-ionizing waves do not have enough energy to release electrons, that is, to ionize and change the atomic structure. Ultraviolet rays, light waves, infrared waves, and radio and television waves are non-ionizing.


Ionization occurs when an electron is removed from the electron shell of an atom. Because living cells and the DNA in those cells can be damaged by ionization, exposure to ionizing radiation increases the risk of developing cancer. The probability of cancer caused by ionizing radiation depends on the dose absorbed by the radiation.

Common sources of ionizing radiation are radioactive substances that emit α, β, or γ radiation and are composed of unstable heavy nuclei similar to helium nuclei, electrons or positrons, and photons.

Ionizing rays are used in industries, nuclear power plants, agriculture, animal husbandry, medicine, etc. In medicine, ionizing rays can be used for cancer diagnosis and treatment, scanning, imaging, and sterilization.

Sterilization of medical equipment by radiation method

Radiation sterilization is done using gamma rays, X-rays, and electron beams.

Radiation has been used to sterilize medical equipment for more than half a century. During this period, the market of disposable medical products has grown tremendously, and the use of ionizing radiation as one of the methods of sterilization has increased. Sterilization is performed on bandages, syringes, needles, blood transfusion systems, medical probes, catheters, surgical sutures, delivery kits disposable clothing, rubber gloves, etc. The sterilization factor in irradiation is higher than other methods.

The main problem in sterilizing medical materials with radiation is to determine the doses that are sufficient for safe sterilization and do not damage the materials.

What is electron beam radiation used for?

Electron beam irradiation is a high-speed process that can be used for a variety of applications, including:

  • Sterilization of disposable medical and pharmaceutical devices
  • Pollution control of packaging, cosmetics, and hygiene products
  • Reinforcement of polymers due to cross-linking and/or breakage of polymers
electron beam

Sterilization by electron beam radiation

Like the other main radiation-based sterilization methods (gamma rays and X-rays), electron beam sterilization can penetrate airless packaging, equipment, and containers. Electrons are produced by accelerators that operate continuously. These rays are responsible for disrupting the DNA chain of any microorganism, inactivating them and thus sterilizing the product. Electron beam sterilization is suitable for low to medium-density products. Electron beam processing for sterilizing disposable medical equipment, heat-sensitive appliances, and radiation-resistant plastic products involves the use of high-energy electrons, typically with energies between 3 and 10 megaelectron volts (MeV). Stents, blood products, plastic tubing, and surgical components are examples of medical devices that can be sterilized by electron beams.

Radiation sterilization damages semiconductors, so it should not be used for medical devices with electronics.

sterilization by electron beam

Does radiation of materials cause radioactivity in materials?

Creating radioactivity in materials depends on the type of particles and the amount of applied energy. A dose higher than 10 mev is not considered for sterilizing medical equipment because less than 10 does not cause radioactivity in the material and higher power can cause radioactivity in the material.

sterilization by electron beam

What are the advantages of using electron beam in sterilization?

  • This method works faster than other radiation methods and damages the product less.
  • Electron beam radiation can penetrate a wide range of materials and deliver the required dose of radiation in just a few seconds, meaning the entire process can be completed in minutes.
  • Due to the high penetrating power of gamma rays and electrons, there is no need to open the package.
  • Much less oxidative damage is done to the product.
  • No chemical residue or induced radioactivity remains on the processed products and the products can be used immediately after sterilization.

Disadvantages of using electron beam

  • Electron power limit up to 10 MeV
  • It requires a high initial capital




Related article: Clean Room (Requirements & Classification)

Click to rate this post!
[Total: 1 Average: 5]

Leave a Reply

Your email address will not be published. Required fields are marked *