Preservatives are included in most finished cosmetic product formulations to protect them from microbiological contamination during normal consumer use. This protection must continue for the expected shelf life of the finished cosmetic product. A microbiological challenge test is performed to evaluate the effectiveness of a preservative system against normal microbiological contamination during the shelf life of a finished product.
In 1999, The Cosmetic, Toiletry, and Fragrance Association (CTFA) surveyed member companies for the purpose of determining what practices for preservative and stability testing are used by the cosmetic industry. The survey was designed to:
• Gather current information from the cosmetic industry on challenge test methods, stability test conditions and preservative adequacy acceptance criteria as applied to cosmetic and toiletry formulations;
• Qualitatively compare the survey findings to the findings of an unpublished preservative stability testing survey that was conducted in 1986;
• Inform the cosmetic microbiologist of current industry practices for preservative challenge and preservative stability testing of cosmetic and toiletry formulations.
The survey consisted of 28 questions ranging from preservative challenge testing to stability test conditions. Questionnaires were sent to CTFA active and associate member companies. The information reported here was provided by 39 companies who manufacture fi nished cosmetic products. The survey did not determine what kinds of cosmetic products the respondents produced, and it did not determine if the products contained added preservatives. All responses were coded to avoid disclosure of company identifi cation and to protect proprietary information.