ISO 11930 is the EU standard, required under the EU Cosmetics Regulation, and uses category-based pass criteria (Categories A and B) depending on product risk. USP <51> is the US pharmacopeial standard and is commonly required by US retailers and FDA-regulated products. Both test the same five organisms but apply different log-reduction thresholds and time points. If you are selling in multiple markets, confirm with your regulatory consultant which standard applies before commissioning testing.
Read the full guide on Preservative efficacy testing →