SIST EN ISO 21148:2017

Overview - EN ISO 21148:2017 (Cosmetics microbiology)

EN ISO 21148:2017 provides general, risk‑based instructions for carrying out microbiological examinations of cosmetic products. Published in 2017 and endorsed by CEN (as EN ISO 21148:2017), it supersedes the 2009 edition. The standard sets out laboratory premises, equipment, personnel, sample handling and test‑preparation practices needed to ensure reliable cosmetics microbiology testing across diverse product types (including low water activity, hydro‑alcoholic and extreme pH formulations). It also notes that some details may not apply to all product types (for example certain water‑immiscible products).

Key topics and technical requirements

EN ISO 21148:2017 covers procedural and technical areas to support consistent microbiological examination of cosmetics:

• Premises and test areas (Clause 4): layout, location, equipping and maintenance of laboratory spaces used for microbiological testing.
• Equipment (Clause 5): requirements for microbiological cabinets, balances, homogenizers, pH meters, autoclaves, incubators, refrigerators/freezers and colony‑counting devices.
• Strains and reference organisms (Clause 6): management of microbial strains used for controls and method validation.
• Personnel (Clause 7): competence, training and hygiene requirements for laboratory staff performing tests.
• Apparatus and glassware (Clause 8): preparation, sterilization (dry heat and moist heat), handling of disposable items and contaminated material treatment.
• Culture media and reagents (Clause 9): preparation, sterilization (including filtration), storage and handling of media and reagents.
• Sampling and sample handling (Clause 10): sampling procedures from products, transport, receipt, storage, conservation and destruction.
• Operating practices (Clause 11): hygienic precautions, preparation of initial suspensions and sample dilutions, and guidance for water‑miscible vs water‑immiscible products.
• Emphasis on a risk analysis approach to determine appropriate test methods for different cosmetic matrices.

Practical applications - who uses ISO 21148:2017

This standard is used by:

• Cosmetic manufacturers for routine microbiological quality control and batch release.
• Contract testing laboratories and QC units to standardize methods and ensure reproducibility.
• Product development teams to design preservative efficacy and stability studies.
• Regulatory and compliance personnel as a reference for best practices in microbiological testing procedures.
• Auditors and certification bodies assessing laboratory competency and test environment suitability.

Related standards and implementation notes

EN ISO 21148:2017 is part of the broader set of cosmetic microbiology guidance documents developed by ISO/TC 217 and CEN/TC 392. Laboratories should implement this standard alongside product‑specific test methods, preservative efficacy tests and national regulatory requirements. Where a cosmetic matrix has atypical properties (e.g., strongly water‑immiscible systems), the standard’s general instructions should be adapted based on documented risk analysis.

Keywords: ISO 21148:2017, cosmetics microbiology, microbiological examination, cosmetic product testing, risk analysis, sampling, culture media, laboratory equipment.