Challenge Test Cosmetics (Preservative Efficacy Test)

Cosmetic challenge testing: ensuring the safety and efficacy of cosmetic products

Cosmetic challenge testing is a crucial step in ensuring the safety and efficacy of cosmetic products. It is a type of preservative efficacy test that is used to determine the ability of a cosmetic product’s preservative system to prevent microbial growth over its shelf life.


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MySwissLab, headquartered in Switzerland, holds accreditation for ISO 9001:2015 and adheres to ISO 14001 & 22716 cGMP standards.



What is a Cosmetic Challenge Test? (PET)

A Challenge test, also called a preservative efficacy test (PET) is a scientific protocol introducing specific test organisms, such as Candida albicans, Escherichia coli, Pseudomonas aeruginosa, or Staphylococcus aureus, into the product to see if the preservative system is able to prevent the growth of these microorganisms.

The product is initially inoculated with microorganisms for the purpose of verifying its capability to fight microorganisms periodically throughout the defined intervals (e.g., Day 7, 14, and 28 as per ISO 11930 guideline). By the completion of this assay process one will be able to discern if their product has antimicrobial protection against the microorganisms introduced.

The main aim of a challenge test is to identify any potential problems with a cosmetic product before it reaches the consumer. By performing challenge tests, cosmetic manufacturers can ensure that their products are safe for use and meet the legal requirements set by their local regulation or for those who seek compliance with ISO 11930.

Why using several test organisms is necessary?

Candida albicans, Escherichia coli, Pseudomonas aeruginosa, and Staphylococcus aureus strains most commonly used in preservation efficacy test because they represent the major types of microorganisms that can cause spoilage, infections, or skin irritation in cosmetic products. Candida albicans is a common fungal strain that can cause skin infections, particularly in people with weakened immune systems. It is a good indicator of the ability of a cosmetic product to resist fungal contamination with direct contact.

Escherichia coli is a gram-negative bacterium that is commonly found in the human gut and is often used as an indicator of fecal contamination. In cosmetic products, it can cause skin irritation and infections.

Pseudomonas aeruginosa is a gram-negative bacterium that is commonly found in water and soil. It can cause skin infections and is a good indicator of the ability of a cosmetic product to resist bacterial contamination.

Staphylococcus aureus is a gram-positive bacterium that is commonly found on the skin. It is a major cause of skin infections and is a good indicator of the ability of a cosmetic product to resist contamination.


The Benefits of Challenge Testing

There are several benefits of challenge testing cosmetic products. These include:

1. Identifying potential problems with a product before it reaches the consumer.
2. Providing qualitative data about the cosmetic formulation and raw materials.
3. Meeting legal requirements set by the European Union and other regulatory bodies.

What are the steps of Challenge

Challenge testing involves several steps, including:

1. Selecting test organisms that are representative of the types of microorganisms that are commonly found in cosmetic products.
2. Introducing the test organisms into the product.
3. Monitoring the product for any signs of microbial growth over a defined interval.
4. Evaluating the results and comparing them to predefined microbial limits.
5. Compiling a test report that outlines the results of the challenge test.

Challenge test is performed in a laboratory setting using a reference method, such as ISO 11930. The product sample is subjected to normal conditions to simulate the environment that it will be exposed to during normal use. A qualified microbiologist ensures the test organisms introduced are viable, establish a positive and negative control, monitor the product for signs of microbial growth during the assay and compile the results in a cosmetic product safety report.

Cosmetic Challenge Testing With Myswisslab+

At MySwissLab+, we understand that each cosmetic product is unique and requires an individual approach to challenge testing. Our one to one approach ensures that your product undergoes appropriate control ensuring strong microbial protection.


At MySwissLab, we prioritize customer satisfaction and make sure that you can reach us whenever you need to. Our team of dedicated customer service representatives is available 24/7 to answer your questions, provide support, and address any concerns you may have by email.

With our reliable and responsive customer support, you can rest assured that you’ll receive the assistance you need in a timely and professional manner.


PET Guarantee Insurance is a unique feature offered at MySwissLab that provides peace of mind to our clients. By topping up the cost of the challenge test with 50€, clients can ensure that if their product fails the test, they are entitled to a free replacement test.

This policy allows clients to confidently test their products without worrying about incurring additional costs for a second test if the first test fails. Our clients can rest assured that if their product fails, they can easily get it retested at no additional cost. This policy is a testament to our commitment to quality and customer satisfaction, ensuring that our clients receive the best service possible



Choosing a Swiss testing lab for cosmetic stability testing allows a brand to make the claim that their products are Swiss-tested, which is highly valued by consumers worldwide. Switzerland is renowned for its precision and high-quality standards, and Swiss testing labs are held to some of the strictest regulations in the world.

By having your cosmetic products tested in a Swiss lab, you can demonstrate to your customers that your brand is committed to upholding the highest quality and safety standards. This can be a significant selling point for consumers who are willing to pay a premium for products that are rigorously tested and meet stringent quality requirements

Frequently asked questions (FAQ) about challenge testing

"Ordering a cosmetic challenge test is easy and simple. All you have to do is send us an email specifying that you wish to place an order. Once we receive your email, we will reply with a list of the information we need to start the process, such as the type of test you want to perform and the samples you will need to send us. Next, we will send you a ""Sample Submission Form"" so that you can provide us with all the necessary information to identify and record the samples you send us. Once we receive the samples, we will perform the cosmetic challenge test and provide you with the results. If you have any questions or concerns at any time, do not hesitate to contact us. "
-European Union and EEA: Comprised of the 27 EU Member States as well as Liechtenstein, Norway, and Iceland. -ASEAN countries: Indonesia, Thailand, Singapore, Malaysia, Philippines, Vietnam, Cambodia, Brunei, Myanmar, Laos. -South Korea: Tests must be conducted by a Korean company or a laboratory certified by the KFDA. -Switzerland -United Kingdom -Israel -Gulf Cooperation Council countries: Saudi Arabia, Kuwait, Bahrain, Qatar, United Arab Emirates, and Oman. -South Africa -Argentina -New Zealand: Providing microbiological specifications is customary, but not mandatory.
Yes, MySwisslab is ISO certified for performing challenge tests according to ISO 11930 standards. Our certification ensures high-quality management systems and accurate results for our clients.
The challenge test typically lasts 28 days, starting from the date we receive the sample. The sample is tested on days 7, 14, and 28 to ensure its conformity. If any non-conformity is observed during testing, we will inform you immediately. Once your sample has been successfully tested three times, the test results will be automatically transmitted to you electronically.
After placing your order, you will receive an email with instructions on how to send your samples directly to our laboratory by postal mail. Please make sure to fill out our sample arrival form so that we can properly identify them.
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