Chlorine dioxide (CD) sterilization is an effective, efficient, clean, “green” method of sterilization appropriate for a majority of medical devices. These “green” benefits, which can be read about here, are making CD a popular alternative to ethylene oxide (EO) sterilization, a common method that has been used for medical devices.

While EO poses little threat to the environment when used properly, it can create significant environmental and health problems should something go wrong. These potential risks have amplified the need for a more environmentally friendly choice, and CD sterilization is meeting that need.

In addition to the “green” benefits, CD sterilization offers medical device developers several other key benefits that make it an effective option.


Perhaps most importantly, CD is not listed as a carcinogen. In most situations, it can be exhausted to the environment; no scrubbing with hazardous solutions needed. It is non-flammable and non-explosive at standard use concentrations.

Compatibility with medical device materials

CD, able to work at room temperature, is compatible with nearly all materials, including plastic components and electronics.

The CD sterilization process also is compatible with commonly used sterile packaging, including pouches, plastic tubs, non-woven polypropylene and paper.

Effectiveness over a wide range of temperatures

CD remains in a gaseous state over a wide range of temperatures and pressures, and is not affected by small temperature changes. It actually is most effective at temperatures of 25°C to 30°C (77°F to 96°F).

Fast bacteria – and spore – kill

While CD has “chlorine” in its name, its chemistry is very different from that of chlorine. It works by oxidizing, not chlorinating. While maintaining the bactericidal, virucidal and sporicidal properties of chlorine, unlike chlorine, it does not lead to the formation of trihalomethanes. Nor does it combine with ammonia to produce environmentally adverse organic compounds.

Through oxidation, CD changes the proteins of a microorganism’s structure. In effect, CD breaks the enzymatic function of the proteins, and as a result, kills bacteria quickly. As a sterilizing – versus disinfecting – agent, CD will also inactivate spores, insuring the complete kill of any antimicrobial life.

Distribution superiority

When it comes to sterilization, size matters – at least in molecular terms. The size of a chlorine dioxide gas molecule is small (0.124 nm), meaning it’s much smaller than microorganisms and viruses. The diameter of the COVID virus, for example, is 50-140 nm. CD’s small molecular size allows the CD gas to penetrate and completely fill any space into which it is injected. That includes organic matter, surfaces – even those with microscopic cracks and crevices – as well as other tight or hard-to-reach areas.

Quick aeration

CD will quickly aerate because it will not condense on surfaces or absorb readily into many materials. This has two important benefits: a reduction in the cycle time of the sterilization process; and the elimination of any time-consuming post-sterilization aeration process.

Real-time measurement

CD gas has a color (yellow-green) and an odor at safe levels, which is similar to chlorine and nitric acid. Both of these features provide the ability to accurately measure, monitor and validate in real time, increasing safety throughout the sterilization process. And since you can smell the gas before it reaches unsafe concentrations, there is ample time to shut down the system and address the situation before any problems occur. Other sterilizing agents can not be smelled until exposure in high concentrations occurs.

Water solubility

Since it is soluble in water, CD gas will retain its sterilization capacity in water, unlike many other sterilization agents. While puddles or pools of water should be avoided, small amounts of water will not affect the effectiveness of CD.

Key chlorine dioxide features

  • Non-carcinogenic, nonflammable
  • Compatible with wide range of materials
  • Works at room temperature
  • Low-impact
  • No exposure to excessive heat, moisture or radiation
  • Ability to kill bacteria and spores quickly
  • Complete distribution
  • Fast aeration
  • Real-time monitoring and measurement ease
  • No post-treatment residuals
  • Water-soluble



CD sterilization offers medical device developers an excellent choice for product sterilization. Effective in killing any antimicrobial life, CD gas is an effective, efficient, safe and environmentally friendly sterilization option.