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Preservative Efficacy Test – Technical Information

Test: Preservative Efficacy Test

Also known as: PET, Challenge Test, Preservative test


This test will determine whether the preservative in your product is working.  We add large numbers of certain micro-organisms to your product and assess how quickly those numbers are reduced.  This test only needs to be carried out once for each product formulation.

MCS Test Reference:   TMPh1

Quantity of product required: 150 g

Total Test Time: 35 days

Test Organisms used:

S. aureus, Ps. aeruginosa, E. coli, C. albicans and A. brasiliensis


Sending Samples:

Samples arriving by Monday morning of each week will go on test that week.

Send samples to the address at the bottom of this page accompanied by a Test Request Form.  Samples do not have to be in finished packaging, clean sample containers are suitable.


Written reports are issued on completion of the test.  Full results with the recovery of each organism at each time point will be given along with a Pass/Fail result.  Early warnings will be given if the product fails to meet any test criteria at earlier time points.