Chlorine Dioxide (CD) Sterilization Residuals Testing
Chlorine dioxide sterilization is the low-temperature, EO-alternative process used for heat-, moisture-, and EO-sensitive devices. Most contract labs don't offer CD residuals testing — most aren't co-located with a CD sterilizer. Boulder BioLabs offers it precisely because we are co-located with Boulder Sterilization, the only U.S. contract sterilizer running CD cycles under ISO 13485.
What Is CD Sterilization Residuals Testing?
Chlorine dioxide sterilization uses gaseous ClO₂ as the sterilant — effective against bacterial spores, fungi, and viruses, at low temperature and low humidity. CD leaves residuals: residual chlorine dioxide plus degradation products (chlorite, chlorate). CD residuals testing quantifies those residuals after aeration and compares them to validated limits.
Our testing protocol combines an extraction step — headspace or exhaustive aqueous — with ion chromatography or spectrophotometric analysis for ClO₂ and its anion degradation products.
Why This Service Is Rare
EO sterilization has a 60-year head start on chlorine dioxide. Most contract labs built their residuals capability around EO and ISO 10993-7, and most don't have a CD sterilizer down the hall. Boulder BioLabs has it because Boulder Sterilization is the only U.S. contract sterilizer offering both EO and CD under ISO 13485.
Peer-Reviewed Toxicity Framework
A peer-reviewed study titled "Chlorine Dioxide Medical Device Sterilization: Residual Toxicity Testing" was published in the Journal of Medical and Biological Engineering in March 2026. It proposed toxicity limits of <6.83 mg/device chlorite and <70.65 mg/device chlorate, providing the regulatory framework Boulder BioLabs operates against. Read the study →
The Strongest Co-Location Story
Boulder Sterilization is the only U.S. contract sterilizer offering both EO and CD under ISO 13485. There is no other location in the country where you can sterilize with chlorine dioxide and run validated residuals testing on the same campus, on the same day, under one quality system.