EN 17516 Cosmetics - Microbiological Limits

The European standard “EN 17516 Cosmetics - Microbiological limits” describes a procedure applicable to all cosmetics that assists stakeholders in assessing the microbiological quality of products. Products considered to have a low microbiological risk do not require microbiological testing.

For the purposes of this standard, the following terms and definitions apply:

• The product is a sample of an identified cosmetic product that is taken to the laboratory for testing.
• Aerobic mesophilic microorganisms are mesophilic bacteria, yeasts and molds that grow aerobically under the conditions specified in the ISO 21149 and ISO 16212 standards.
• The microorganisms mentioned are aerobic mesophilic bacteria or yeasts that are undesirable in a cosmetic product because they cause skin or eye infection or are an indicator of hygienic failure. For example, Escherichia coli are gram-negative rods, motile, smooth colonies. Pseudomonas aeruginosa are gram-negative rods, motile, smooth colonies. They are brown or greenish pigmented. Staphylococcus aureus are gram-positive cocci. Often clustered in grape-like clusters, the smooth colonies are usually yellow pigmented. Candida albicans is a yeast that forms white to beige, creamy and convex colonies on the surface of a selective medium.

In principle, cosmetics, the raw materials from which they are composed and the conditions in which they are produced do not have to be sterile. However, microorganisms present in a product should not have an adverse effect on consumer safety or product quality during its intended or foreseeable use. Therefore, quantitative or qualitative microbiological limits are set for finished cosmetic products.

A concentration of 1 x 10³ ^CFU or less per gram or mL of product is considered acceptable for topical applications. However, particular attention should be paid to cosmetics specifically designed for use in the eye area, in children under three years of age, and on mucous membranes, where a concentration of 1 x 10² CFU or less per gram or mL of product ^is considered acceptable. Additionally, the interpretation of out-of-bounds results should take into account the intrinsic variability of the plate counting method. Furthermore, 1 g or 1 mL of product should be free of Escherichia coli, Staphylococcus aureus, Pseudomonas aeruginosa, and Candida albicans.

The EN 17516 standard specifies microbiological limits for cosmetics. Where necessary, international standard test methods included in the annex of the standard should be used to assess compliance (Annex A).

To ensure product quality and consumer safety, it is essential that the number of unspecified microorganisms recovered from the product remains constant or decreases over the life of the product. The presence of unspecified microorganisms should not be considered as undesirable unless they are capable of growing in the product. This may be based on a risk assessment including preservation effectiveness studies (EN ISO 11930 Cosmetics - Microbiology - Assessment of antimicrobial preservation of a cosmetic product) or on demonstration that the product is unable to support microbial growth (ISO 29621 Cosmetics - Microbiology - Guides for the risk assessment and identification of microbiologically low risk products).

Based on these considerations, the microbiological limits specified in the table given in the standard are valid.

Microbiological limits on cosmetic products aim to prevent illness from occurring in products containing unsafe levels of microorganisms.

Cosmetics manufacturing companies are responsible for the microbiological safety and quality of their products to ensure that they are produced under hygienic conditions.

Regarding microbiological quality control, two categories of cosmetics are defined:

• Category 1: Products designed especially for children under 3 years of age, the eye area and mucous membranes.
• Category 2: Other products.

Briefly, the quantitative limits for cosmetics are as follows:

• Limit for cosmetics classified in Category 1: Total viable count for aerobic mesophilic microorganisms, 0,5 in 10 g or mL of product² Not more than CFU/g or mL.
• Limit for cosmetics classified in Category 2: Total viable count for aerobic mesophilic microorganisms, 0,1 in 10 g or mL of product³ Not more than CFU/g or mL.

Among the numerous tests, measurements, analyses and evaluation studies that our organization has carried out for businesses in various sectors, it also provides testing services defined in the “EN 17516 Cosmetics - Microbiological limits” standard with its trained and expert staff and advanced technological equipment.