Preservative Efficacy Testing (PET), also called a challenge test, checks how well a product resists microbial growth. This testing focuses on bacteria, yeast, and mold. It applies after the product is opened or contaminated.
Water-based products support microbial growth easily. Because of this, manufacturers must confirm that preservatives work as intended. PET helps protect consumers and maintain product quality during shelf life.
At Pentyl Labs, we recommend industry-recognized challenge test standards. These standards depend on product type and regulatory needs. We commonly perform ISO 11930, USP <51>, and EP 5.1.3 testing. PCPC challenge methods are also available when required.
ISO 11930 applies to cosmetic products sold in the EU, UK, and many global markets. USP <51> applies to drug and OTC products. EP 5.1.3 supports European pharmacopoeia compliance.
Many manufacturers also use ISO 29621. This standard helps assess microbiological risk. It does not replace a challenge test. Instead, it supports testing decisions and regulatory documentation.
Most water-containing products require preservative efficacy testing. These products include creams, lotions, serums, cleansers, shampoos, and liquid makeup.
Pentyl Labs provides clear and reliable PET results. Our reports support global compliance and product launch timelines.
Preservative Effectiveness / Challenge Testing – Pentyl Labs
