Medical Device Sterilization

Chlorine dioxide gas, ClO₂ (CD) has been providing true sterilization, similar to EtO, for medical devices for over 25 years. While EtO is a very effective sterilant, CD has many benefits over EtO for a variety of applications. Both are gasses which have the ability to reach all of the individual organisms to provide desired SAL levels utilizing 6-log sporicidal BI’s. The CD concentration can easily be measured with a built-in UV-VIS spectrophotometer ensuring the efficacy of every cycle and allowing for parametric release. Unlike vapor methods, Chlorine dioxide, being a gas, offers repeatable and consistent kill. Unlike some novel gas methods, CD has over 25 years of use since it was developed by Johnson & Johnson for sterilizing suture products, artificial joints, and implantable contact lenses.

Chlorine dioxide is the method usually recommended when devices have imbedded batteries which are not affected by CD. CD does not get absorbed into materials like EtO does, so an aeration time of under 30 minutes is typical. Chlorine dioxide is a true sterilant gas and works at true ambient temperature. The boiling point of CD is low, at -40°C. CD gas will not condense on devices. It is a surface sterilant, therefore CD gas can sterilize prefilled syringes, while maintaining drug integrity, and medical devices with complex geometries.

CD is also not listed as a carcinogen. In almost all locations, it can simply be exhausted to the environment rather than needing to be scrubbed with hazardous solutions. It is non-flammable and non-explosive at use concentrations, so it does not require expensive damage limiting construction.

Treatment cost can be as low as $5 per load.

Only CD (ClO₂) sterilization offers all the following benefits

Chlorine dioxide gas sterilization is ideal for sensitive biotech products and improves supply chain efficiency:

Ambient temperature sterilization (0°C – 50°C) – can be customized for unique applications
Adjustable vacuum levels – can be customized for unique applications
Surface sterilization process – does not get absorbed in most materials for quicker aeration
Short cycle times – 1 to 8 hours including aeration
Safe and easy to bring in house – reduces manufacturing time and cost

Aerates Rapidly – Minutes vs. Days

Properties as a non-vapor, surface sterilant with a low boiling point, coupled with the low CD sterilant concentrations, translates into rapid aeration of the sterilization chamber and exposed products.
CD does not permeate or become absorbed in materials to the same degree as other methods, greatly reducing the overall cycle time of the sterilization process and eliminating the lengthy post-sterilization aeration.

Low Residue Levels – Non-carcinogenic, non-cytotoxic and non-teratogenic

CD’s properties combined with the rapid aeration process results in residues below detectable levels on product and packaging. CD’s sterilant residues are non-carcinogenic, non-cytotoxic and non-teratogenic. Sterilized packages and products may be handled immediately after the cycle.

Flexible to Design Custom Cycles – Optimize Materials Compatibility and Sterilization

Process Parameter	Range
CD Gas Concentration	From 1 mg/L to 20 mg/L
Exposure Time	Varies with application
Door-to-door Time	1 to 8 Hours
Relative Humidity	Typically 65% to 90%
Depth of Vacuum	5 to 101 kPa
Chamber Temperature	Ambient – 50°C

Compatible with Medical Device Materials

CD is less oxidative than traditional oxidizing sterilants like hydrogen peroxide, ozone, NO₂ and peracetic acid. ClorDiSys has tested many medical device materials including non-ferrous metals, polymers, batteries, tissues, bone products, and collagens. Compatible materials showed no increase in cytotoxic response. The true room temperature performance of the CD process allows temperature sensitive materials to be processed.

Compatible with Common Packaging

CD’s sterilization process is compatible with commonly used sterile barrier packaging. This includes: non-woven polypropylene, Tyvek® pouches, Tyvek®-Mylar® pouches, plastic tubs with Tyvek® lids as well as cellulosic materials such as paper and cardboard.