THE LONG AND STORIED HISTORY OF CHLORINE DIOXIDE
Since its discovery more than 200 years ago, chlorine dioxide (CD) has enjoyed a long history of research and use as a disinfectant, sanitizer and sterilizer. This versatile and effective chemical compound (ClO2) can exist as a yellow-green gas above 11 °C (52°F), a red-brown liquid between 11 °C and −59 °C (52°F and -74°F), and as bright orange crystals below −59 °C (-74°F).
Sir Humphrey Davy, a British chemist and inventor, discovers CD when he adds sulfuric acid (H₂SO₄) to potassium chlorate (KClO₃).
CD’s first use to solve taste and odor issues takes place at a water treatment plant in Niagara Falls, New York. The objective is to eliminate phenols in water.
Brussels, Belgium, switches from chlorine to CD for its drinking water disinfection operations. This marks the first large scale use of chlorine dioxide for potable water treatment.
The Environmental Protection Agency (EPA) registers CD, in liquid form, as a disinfectant and sanitizer. Indicated uses include food processing, handling and storage of plants, bottling plants, washing fruit and vegetables, sanitizing water, controlling odors and treating medical wastes.
Hundreds of municipal water systems across Europe, and to a lesser degree, the United States, convert to CD for drinking water disinfection. The conversion is catalyzed by a safer environmental profile of CD over chlorine.
The EPA registers CD in the gaseous form (produced from sodium chlorite) for use in sterilization. Indicated uses include sterilizing manufacturing and laboratory equipment, environmental surfaces and rooms.
Use of CD as a disinfectant, sanitizer and sterilizer grows across Europe and the United States, and throughout many industry sectors: beverage industry; fruit and vegetable processing plants; pulp and paper industries; and industrial waste treatment sites.
Commercial use: 1990s
During this decade, Johnson & Johnson and Abbott Laboratories, extensively studied CD in its gaseous form as a sterilizing agent. Both companies realized significant advantages in using CD to sterilize medical devices, and conducted successful tests on products including surgical kits, suture products, artificial joints and implantable lenses. One of the first commercial uses was Johnson & Johnson’s use of its proprietary CD technology to sterilize implantable lenses and desktop surgical instrument sterilizers.
FDA Innovation Challenges
In mid-2019, the U.S. Food and Drug Administration (FDA) announced two public innovation challenges to encourage development of new sterilization methods that could include new devices or new modalities that are safe and effective for sterilizing medical devices – while at the same time reduce adverse impacts on the environment.
The first was to identify new sterilization methods and technologies, looking to boost the development of new approaches that did not rely on ethylene oxide, a commonly used sterilization agent for medical devices. The second was specifically to reduce ethylene oxide emissions, getting as close to zero as possible.
CD gas has been providing true sterilization of medical devices for several decades. The FDA challenges are fueling the demand for CD, effectively creating a major opportunity for CD to become a key environmentally friendly option for sterilization of many types of medical devices.