Overview
EN ISO 21322:2021 (ISO 21322:2020) provides guidance for microbiological testing of impregnated or coated cosmetic products such as wipes and masks. Adopted by CEN, this standard addresses the special sampling and analytical challenges when a cosmetic formulation is fixed to a substrate and not directly accessible. The document also explains how the same principles can be adapted for similar items (e.g., cushions, impregnated sponges, applicators like brushes, puffs).
Key topics
- Scope and principle - Guidance for enumeration and/or detection of microorganisms in coated or impregnated products where standard sampling is difficult.
- Sample selection and preparation - Recommendations for selecting representative pieces and preparing initial suspensions.
- Recovery techniques - Methods to extract microorganisms from substrates (e.g., stomaching, shaking/stirring) and considerations for improving recovery.
- Enumeration methods - Plate count approaches (pour plate, surface spread) and membrane filtration for counting aerobic mesophilic microorganisms.
- Detection by enrichment - Procedures for detecting specified microorganisms using enrichment and selective media.
- Diluents, neutralizers and media - Guidance on appropriate diluents, neutralizers and culture media to neutralize preservatives and support recovery.
- Apparatus and strains - Required laboratory equipment and reference strains for suitability testing.
- Procedure, expression and reporting - Detailed steps for testing, how to express results, suitability tests and the content of the test report.
- Annexes - Includes normative guidance for wipes and masks (Annex A), interpretation of results (Annex B), and a suitability test method (Annex C).
Practical applications
Who uses EN ISO 21322:2021:
- Cosmetic manufacturers performing product-release and routine microbiological quality control of impregnated wipes, facial masks and similar products.
- Contract testing and microbiology laboratories performing method validation, suitability tests and contamination investigations.
- Regulatory and compliance teams assessing product safety and documentation for market access in CEN/European countries.
- R&D teams developing new delivery formats (impregnated sponges, cushions, applicators) that require adapted microbiological methods.
Typical uses:
- Product release testing, stability and shelf-life studies, supplier qualification, root-cause analysis of contamination, and harmonizing test methods across sites.
Related standards
EN ISO 21322:2021 complements other cosmetics microbiology standards and general microbiological methods used for enumeration, membrane filtration and enrichment. Laboratories should apply this standard together with national regulatory requirements and other ISO/CEN guidance relevant to cosmetics microbiology.