A Glance at Sterilization Technologies

Sterilization is an important aspect of cleanroom technology, and the demand of sterilized cleanroom products keeps growing over the past ten years.

Four Types of Sterilization

Since many methods exist and new methods are coming into practice, it’s important to understand and select one that’s best for your product(s). As the first step, let’s take a quick look at the current situation.

Heat Sterilization

Wet Heat/Steam Sterilization is a simple yet very effective decontamination method. Sterilization is achieved by exposing products to saturated steam at high temperatures (121°C to 134°C). Product(s) are heated through pressurized steam to kill all microorganisms.

Dry Heat Sterilization expose product(s) to high temperatures either by flaming, incineration or a hot air oven to kill bacteria.

Gas Sterilization (Ethylene Oxide)

Heating provides a reliable way to get rid of all microbes, but it is not always appropriate as it can damage the material to be sterilized. In that case, chemical methods for sterilization is used which involves the use of harmful liquids and toxic gases without affecting the material.

The commonly used gases for sterilization are a combination of ethylene oxide and carbon-dioxide. 

Filtration Sterilization

Filtration is the quickest way to sterilize solutions without heating. This method involves filtering with a pore size that is too small for microbes to pass through. Generally, filters with a pore diameter of 0.2 um are used for the removal of bacteria.

Radiation Sterilization (Gamma, Electron-beam, X-Ray)

Commercial radiation sterilization has existed since the late 1950s and has grown tremendously in popularity over the last 60 years. Three forms of radiation commonly used for commercial radiation sterilization include gamma radiation, electron beam (e-beam) radiation and X-ray radiation.

Globalization Sterilization Market

The sterilization market is comprised of about 50% gas sterilization, the most prevalent form. 40.5% gamma-based sterilization stands in the second place. The increasing availability of high-power electron accelerators has made E-beam and X-ray based technologies popular alternatives.

Global Sterilization Market Volume Shares [1]

EO Sterilization versus Gamma Sterilization [2]

EO Gas and Gamma Radiation are two major methods in sterilization market. So how do they compare? 

EO Sterilization

- Advantages

  • A wide range of materials can be sterilized using this process.
  • Because EO penetrates cartons and sealed films, already packed materials can be sterilized using the process.

- Disadvantages

  • Ethylene Oxide is considered a carcinogenic and may have harmful effects on human beings.
  • The process has more variables that need controlling than gamma sterilization.
  • EO is highly flammable and in the presence of air, the gas can produce its own oxygen.
  • Possible residual smell and discoloration of the materials.

GAMMA Sterilization

- Advantages

  • Gamma radiation is the ideal option for materials that are to be stored for an extended period of time.
  • The process does not generate heat or moisture.
  • It is more cost effective and more sterile than EO sterilization.
  • After the sterilization process, there is no residual radioactivity.

- Disadvantages

  • After sterilization using gamma rays, some materials may be slightly discolored. However, this has no effect on performance, on the contrary, some plastics perform better after irradiation.

KM does support multiple sterilization methods, like Gamma radiation, wet steam, and EO gas.


[1] A Comparison of Gamma, E-beam, X-ray and Ethylene Oxide Technology for the Industrial Sterilization of Medical Devices and Healthcare Products , Gamma Industry Processing Alliance, 31 Aug 2017

[2] EO Sterilization Versus Gamma Sterilization, International Enviro Guard, 6 Ari 2019