Article: Development And Quantification Of H₂O₂ Decontamination Cycles

By Dip. Ing. (FH) Volker Sigwarth and Dr. Claude Moirandat, PharmaSystems, Inc.

Whereas correlation of physical process parameters with bacterial reduction is well established in thermal sterilisation, such a method is currently neither generally recognised nor possible for H2O2 decontamination. As a result, the efficiency and reproducibility of H2O2 decontamination and the course of the process over time can at present only be ascertained, verified, and documented using a microbiological system.

Based on the "Fractional Negative" method of determining the D-values of Biological Indicators (BIs), which is contained in the ISO 11138-1 and EN 866-3 standards, a complete and systematic method is presented that enables the parameters for each cycle phase to be determined and verified, and the effectiveness of the process to be quantified. The method also enables differences in bacterial reduction between positions which can be effectively decontaminated and "worst case" positions to be quantified, so that, using the results, the process can be individually adjusted to specific overall bacterial reduction requirements. The new method also specifies the procedure for assessing the suitability of the microbiological system used prior to qualification and validation a conditio sine qua non if process parameter studies are to be used to establish and document a decontamination cycle.