Service
Cosmetic challenge testing service.
The challenge test proves your preservative system holds up in real use. We run the full ISO 11930 preservative efficacy test through our accredited laboratory and report the result against Criteria A and B, ready for your safety file.
Reviewed by Cassandra Maddocks, chemist & biochemist · last reviewed 28 July 2026
Challenge testing (preservative efficacy), run for you.
We inoculate your product with the reference organisms and track them over the 28-day ISO 11930 protocol, then report the result graded against Criteria A and B. It proves your preservative system controls what a consumer introduces in use, or tells you to reformulate before you commit to a print run.
The protocol and the A-versus-B grading are explained in our challenge testing guide.
What is included?
The preservative efficacy test to ISO 11930, inoculating the five reference strains, sampling on days 2, 7, 14 and 28, and a report stating conformity against Criteria A and B. Where a product may qualify as low risk under ISO 29621, we assess that too.
This is the test that catches a weak preservative system in the lab rather than on the shelf.
How much does it cost and how long does it take?
It is quoted per product and runs 28 days from sample receipt, because the elapsed time is the measurement and cannot be compressed. We scope it up front and quote a fixed price, and we plan it alongside your file so the 28 days never sit on the critical path unnecessarily.
Send us your product and preservative system: request a testing quote.
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