Challenge Testing for Cosmetics

Challenge Testing for Cosmetics

To assess the robustness of your products against microbial contamination, we have designed and developed the challenge testing for cosmetics, also known as preservation efficacy testing (PET). The QACS Laboratory challenge testing for cosmetics falls within the scope of our ISO 17025 accreditation. The challenge test results are crucial in determining the safety of your cosmetic products, in line with the requirements of Regulation (EC) No 1223/2009.

Why challenge testing is important

Before market launch, cosmetics must be tested by accredited labs to ensure that they are suitable for use by customers as stipulated in Regulation (EC) No 1223/2009.

For a cosmetic product to be placed in the market, a responsible person must be designated within the EU for this product.

According to the Notes of Guidance issued by the Scientific Committee on Consumer Products (SCCP) of the European Commission Directorate-General for Health and Consumer Protection, “The responsible person must guarantee the efficacy of the preservation of his products experimentally by challenge testing. However, as no legal or universal challenge test method is currently available, it is up to the responsible person to decide on the details of the test to be used.”

How we report the results

We issue intermediate results for all new products we test. This assists your R&D decision-making process, so your products can reach the market faster.

Evaluation of preservation efficacy is crucial when developing and launching new cosmetic products, as tight R&D deadlines apply.

We schedule our challenge tests as soon as we receive a new product for testing. This reduces lead time to a minimum.

You receive preliminary real-time reports on intermediate readings throughout the screening process. If you are based in the EU, we offer 24-hour courier service.

If you need your test results urgently, we can perform a fast screening process within 14 days.

Which challenge testing protocols we use

We use a wide range of protocols for challenge tests on cosmetics. Our experienced scientists determine the best and most cost-efficient challenge test for your needs.

The test

The European Pharmacopoeia (EP) and United States Pharmacopeia 51 (USP 51) reference standards involve challenging the preparation in its final container, wherever possible. They use a prescribed inoculum of suitable micro-organisms (Pseudomonas aeruginosa, Staphylococcus aureus, E. coli, Candida albicans, Aspergilus brasiliensis).

Screening is performed by:

  • Storing the inoculated preparation at a prescribed temperature.
  • Withdrawing samples from the container at specified intervals of time.
  • Counting the organisms in the withdrawn samples.

The results

The results are available within 35 days.

The preservative properties of the preparation are adequate if there is a significant drop or no increase, as appropriate, in the number of micro-organisms in the inoculated preparation at the temperatures and time prescribed.

Minimum sample quantity

100g

The test

The ISO 11930 Cosmetics – Microbiology – Evaluation of the antimicrobial protection of a cosmetic product is a reference method used to evaluate the preservation of a cosmetic formulation.

For each test micro-organism it involves:

  • Placing the formulation in contact with calibrated inoculums (20g of the test formulation, 0.2 ml of calibrated inoculums).
  • Measuring the number of surviving micro-organisms at defined intervals during a period of 28 days.
  • Storing the containers of inoculation formulation at (22.5±2.5)°C.
  • Making successive ten-fold dilutions by means of a plate count method.

For each time and strain, the log reduction value is calculated and compared to the minimum values required for evaluation criteria A or B.

The results

The results are available within 35 days.

Minimum sample quantity

100g

The test

The re-inoculation protocol is similar to the EP reference standard. Samples are re-inoculated on the 7th day. Observations are repeated after the times prescribed. The test is prolonged by 7 days.

The results

The results are available within 42 days.

Minimum sample quantity

100g

The test

The multi strain in-house mixed culture test is designed to simulate single inoculation followed by a storage period.

The test consists of:

  • Dividing several standard strains in categories of bacteria, yeasts and moulds.
  • Challenging the preparation with a mixture of strains.

The results

The results are available within 42 days.

Readings are reported per strain. The preservative properties of the preparation are adequate if there is a significant drop or no increase, as indicated by the EP criteria, under the conditions that the test is performed.

Minimum sample quantity

100g

The test

On wet wipes, sample preparation is a critical issue.

The wet-wipe related recontamination involves:

  • Separately contaminating wet-wipe sub-samples with each one of 5 reconstituted strains.
  • Testing individual sub-samples for microbial count at every interval (0 time, 2 days, 7 days, 14 days, 28 days).
  • Assessing log-reduction.

The rest of the test complies with the EP reference standard.

The results

The results are available within 35 days.

Minimum sample quantity

100g

How much do the challenge tests cost?

Fill in our contact form to request our price list and find out how our QACS Laboratory team can help you.