Decision risk approach to the application of biological indicators in vapor phased hydrogen peroxide bio-decontamination

Éva Pusztai, S. Kemény, Emese Vágó, Anikó Horváth

Research output: Contribution to journalArticle


The ensuring of sterile conditions during pharmaceutical production is of vital importance. Restricted access barrier systems may not be sterilized in the usual way. Instead, vaporous hydrogen peroxide decontamination is used. The success of the decontamination is checked by placing biological indicators (BIs), and upon their removal, putting them individually into broth for incubation. This technique does not allow counting the number of microorganisms but to detect the survival of any of them and thus counting the negative/positive answers. The Poisson distribution gives the connection between the number of viable spores and the number of positive (growth) BIs. Evaluation is based on the number of surviving BIs, which is probabilistic by nature. Acceptance limits are based on good engineering assumptions (“current industrial experience”), not on sound decision theory statistics (probability of error of the first and second kind). The reason of existence of surviving BI is either the process lethality failure or the limited penetrative capability of vaporous hydrogen peroxide. The latter phenomenon is called “rogue” BIs, and it should be distinguished. The method of the evaluation of the success of the decontamination is consistent with attribute sampling plans. In this paper, relations are explored to calculate the 2 types of error that can be applied in general during the qualification of a bio-decontamination procedure. This is, to the best knowledge of the authors, the first ever application of attribute sampling plans to evaluate the results of a BI used bio-decontamination process.

Original languageEnglish
Article numbere3015
JournalJournal of Chemometrics
Issue number4
Publication statusPublished - Apr 1 2018



  • bio-decontamination
  • log reduction
  • risk analysis
  • rogue biological indicators
  • vapor phased hydrogen peroxide

ASJC Scopus subject areas

  • Analytical Chemistry
  • Applied Mathematics

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