Special Issue Cosmetics Part 15: Handling Microbiologically Conspicuous Results - Part 2: Practical Examples and Root Cause Analysis
Jun 16, 2017 - Cosmetics
Special Issue Cosmetics Part 15: Handling Microbiologically Conspicuous Results - Part 2: Practical Examples and Root Cause Analysis
Introduction
In the last Special Edition Cosmetics Part 14, we primarily addressed the general procedure for dealing with microbiologically notable results. In this newsletter, we would like to present two practical case studies. Additionally, a possible approach to root cause analysis is demonstrated using a fishbone diagram as an example.
Dealing with Microbiologically Notable Results: Case Studies
Case Study 1:
Results of the microbiological examination of a cosmetic product:
- Parameter Total count of aerobic mesophilic bacteria: 60 CFU/g
- Identification: Bacillus spp.
- Limit: 1000 CFU/g
Bacillus spp. are spore-forming bacteria. Spores of Bacillus spp. are widespread in our environment. They can be found virtually everywhere, e.g., in water, raw materials, on plants, in humans... and they are highly resistant to environmental influences (e.g., heat). Due to these properties, the spores of Bacillus spp. can often survive the production process. Since they are neither classified as "specified microorganisms" nor as classic spoilage organisms in cosmetics, germ counts below the threshold are generally considered non-critical.
Case Study 2:
Results of the microbiological examination of a cosmetic product:
Parameter Total count of aerobic mesophilic bacteria: 50 CFU/g
Identification: Pluralibacter gergoviae (formerly Enterobacter gergoviae)
Limit: 1000 CFU/g
This bacterium is known for the so-called "Phoenix effect" (see box). Thus, the result is considered critical. Follow-up investigations, even after several days or weeks, as well as a review of the process for hygiene weaknesses must be initiated (see also Newsletter Part 1).