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Which Preservative Efficacy Test (PET) do I need?

All cosmetic products that are to be sold on the market require a Product Information File (PIF). The PIF contains details of the challenge test (PET test) of your product alongside the results of a stability test and manufacturing details.

If you are not sure which microbial challenge test (PET test) you require, then find out more here.

EP USP ISO
UK ● ○
EU ● ○
USA ●
World ● ○ ○

● Recommended
○ Acceptable (customer dependant)

EP - European Pharmacopoeia - 5.1.3 “Efficacy of Antimicrobial Preservation"
USP - United States Pharmacopeia - Chapter 51 “Antimicrobial Effectiveness Testing”
ISO - ISO 11930 - “Evaluation of the antimicrobial protection of a cosmetic product”

EP, USP or ISO standard PET test?

The challenge test protocol that you require is governed by the market that you intend to sell your products into.

The EP test method for Europe / UK and the USP method for the USA are well established protocols, offering formulators confidence that their products are robustly protected. The methods are also accepted in many other territories.

The ISO 11930 method has been introduced more recently. Although it is considered a less stringent test than the EP or USP, unlike these Pharmacopoeia test methods, ISO 11930 was designed specifically with cosmetics in mind.

Customer demand

Alternative methods

EP USP ISO
Incubation (days) 28 28 28
Sample required (g) 250 250 250
Total Species 4/5 5 5
Staphylococcus aureus ● ● ●
Pseudomonas aeruginosa ● ● ●
Candida albicans ● ● ●
Aspergillus brasiliensis ● ● ●
Escherichia coli ○ ● ●

● Required
○ Optional (Oral products)

EP - European Pharmacopoeia - 5.1.3 “Efficacy of Antimicrobial Preservation"
USP - United States Pharmacopeia - Chapter 51 “Antimicrobial Effectiveness Testing”
ISO - ISO 11930 - “Evaluation of the antimicrobial protection of a cosmetic product”

PET test details

The major differences between the methods are noted in the table opposite. For oral care products, testing against Escherichia coli is an additional requirement of the EP method. The cost of a cosmetic challenge test varies by the type chosen.

The ISO 11930:2019 method uses less stringent pass criteria compared to the pharmacopoeia methods.

Customised tests

We can offer bespoke versions of the above-mentioned tests, for example, using extended incubation times, repeated inoculations, use of additional organisms or specific strains.

Please Contact us to discuss your specific requirements.