Cosmetics challenge test

Why do you need a cosmetics challenge test?

The cosmetics challenge test, also known as the preservative efficacy test (PET), is an important part of the Product information file, and reference to it must be made in the cosmetic product safety report (CPSR). According to ISO 29621, every cosmetic manufacturer has to ensure that the product, as purchased, is free from the numbers and types of microorganisms that could affect product quality and consumer health, as well as to ensure that microorganisms introduced during normal product use will not adversely affect the quality or safety of the product. The latter can be ensured by performing the cosmetics challenge test.

Basically, the challenge test checks how effective the preservative system of the cosmetic product is and whether it is capable of withstanding various types of contamination during production, from the environment and from direct contact with the human body that the cosmetic product is exposed to, thereby guaranteeing the safety and efficacy of the product during its shelf life.

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How is the cosmetics challenge test performed?

CE.way checks the preservation system's effectiveness using the international cosmetics challenge test standard ISO 11930:2019 or the United States Pharmacopeia standard USP 51. The test is based on the monitoring of the presence of various pathogens in the cosmetic product when it is produced, followed by the intentional inoculation of a cosmetic product with five different strains of microorganisms:

Staphylococcus aureus (gram-positive bacterium)

Pseudomonas aeruginosa (gram-negative bacterium)

Candida albicans (fungus)

Escherichia coli (gram-negative bacterium)

Aspergillus brasiliensis (fungus)

The remaining concentration of these microorganisms is then determined after 7, 14 and 28 days. The product is considered to pass the preservative efficacy test if the concentrations of the fungi do not increase over the testing period and if the concentrations of the bacteria are reduced sufficiently by day 14 and do not increase from that time until the end of the test.

When is a cosmetics challenge test not needed?

A cosmetics challenge test is not required for certain types of cosmetic products. Microbiologically low-risk products can be exempt from the preservative efficacy test, because, due to the product characteristics, the likelihood of microbiological contamination for such products is very low or even non-existent. The product characteristics that define products as microbiologically low-risk products are described in ISO 29621:2017 and can be divided into characteristics due to the composition of the product, characteristics that are a consequence of the production conditions, packaging or combined factors.

These characteristics are as follows:

Water activity of formulation: products that do not contain water

The pH of the formulation: highly acidic (pH below 3) or highly alkaline (pH above 10) products

Alcohol content: products with more than 20% alcohol concentration

Formulation with raw materials that can create a hostile environment: such as strong oxidizing agents, polar organic solvents, oxidizing dyes, aluminium chlorohydrate and related salts or propellant gases

Production conditions: if containers are filled at more than 65 degrees Celsius

Packaging types: product packaged in pressurized containers, pump dispensers or single-dose units

A combination of the above-mentioned factors

Any lack of challenge test, however, must be duly justified.

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And what do they say about us?

Pharmaplast began to work with CE.way almost one year ago. CE.way is our cosmetics consultant who look after compilation of PIF, safety assessments and CPNP notifications. In addition to this, CE.way is our European representative as our company is not located in Europe. Working with CE.way has been a joy so far. Their replies are very swift and Mr Tadej is very cooperative, helpful and with a deep knowledge about the cosmetics regulations. In addition to this, CE.way is very cost effective company in comparison with their European counterparts. For all the above reasons, I really recommend CE.way to other cosmetic product manufacturers.

Mena, Egypt


We were looking for a stand-alone service, not too sure what to expect... The professionalism, the assistance and the responsiveness were very much appreciated, amongst the best we have ever experienced.

Carol, Switzerland


We are a small manufacturing company located in the US. We recently used CE.way Regulatory Consultants to help guide us through the Cosmetic regulatory changes that have taken place in the EU. They were instrumental in helping us understand the new laws and streamline the entire process. I would highly recommend their services.

Lena and Clay, USA


We didn't have any knowledge about the registration process for cosmetics in EU and were very concerned about this, but we met CE.way and they gave us whole packages of consultation and support. It was really helpful and we could do the registration without any problem. We will definitely ask CE.way again when we have new product to register in EU.

Masa, Japan

Nash Corporation

We used Tadej and CE.way for EU compliance with our products. He was very helpful and worked directly with our lab which made the process much easier for us. Tadej worked with me directly on all of our products to make sure I had the right documents. I really liked the attention to detail and how I could work with the owner of the company directly. I would highly recommend their services.

Steve, Canada

Curly Hair Solutions

Tadej from CE.way is the best consultant I've ever worked with. It's a great luck that we've found him. He is knowledgeable, fast, helpful & always ready to answer a million questions that we have. We had no exposure to cosmetics market before, so we didn't even know where to start. So he helped us to do EVERYTHING. The quality of service for the amount of money that we pay is absolutely the best! BIG THANK YOU to you Tadej & we'll definitely keep working with you!

Natalia, USA

Hi Tadej, Thank you for your highly professional approach, extremely helpful information and advice on getting our product registration under way and completed in record time! What we thought to be a very tiresome and laborious task was made quick and simple. Thank you again! The Thermitek Team.

Rene, Greece


It's been our first time lodging an application for EU Compliance. Although a big task, Tadej from CE.way made it as painless as possible. His patience and help were invaluable. He was so responsive and was available at all times to work with myself and my manufacturers. We now have our first round of product successfully assessed and notified. I will be placing our next round asap for notification, I can't recommend CE.way highly enough, thanks Tadej - Heather Spierings Eye of Horus Cosmetics.

Heather, Australia

RA Cosmetics

CE.way offers professional and reliable service. The team is diligent and extremely helpful throughout the whole process. We are very satisfied the way the work was executed. We definitely recommend CE.way to others.

Tamar, USA


CE.way made the whole EU process easy to understand. They were very responsive to all our needs.

James, USA


This is a major investment for a small business like ours and it took me a few years to find a company (CE.way) that I felt comfortable working with! That speaks volume to my appreciation of the quality of your communications with me.

Vivian, USA

VB cosmetics

Our company had a great experience with CE.way. They were very organized and provided us with a detailed roadmap of exactly what we needed to gather on our end for them to put together our Product Information File and complete the notification process for the EU. They continued to help us along the way, providing quick feedback on any changes we needed to make to a document for it to work and reminders on what we still needed to provide. They are organized, knowledgeable, fast, and attentive; I would absolutely recommend them to any companies looking to get their products approved in the EU.

Cyrus, USA


CE.way's assistance was tremendous, helping our company navigate the EU cosmetic regulation and efficiently get products to market.

Mike, USA


Our cooperation with Tadej and his team at CE.way Consultants aimed to assist us to launch our products in UK for the first time. Tadej is a very hands on and always quick with his responses. The process was smooth and beyond our expectations in terms of cost savings and the speed with which we accomplished our goal. We look forward to working with them again.

Ruta, UK

Art de Parfum

We are really appreciate your speedy replies and clear and understandable guide. As there are a lot of differences in cosmetic regulations between Japan and EU first we thought that it would be hard to make all necessary procedures for our products compliance with EU laws, but thanks for your prompt support, all procedures were made smoothly. And now we are successfully selling MT Metatron in EU. We also thinking to expand our other brands in EU and when we start - definitely will ask your company for assist again.

Olga, Japan

MT Cosmetics, Inc.

After a less than pleasurable experience with another company, we found CE.way and we can honestly say that it could not be more beneficial for our brand. The whole notification process is made as easy as possible. The people at CE.way are all very accessible, knowledgeable and always ready to answer questions. CE.way is a great asset to our company and we are grateful for all the help and support we receive. Navigating through all rules and regulations alone is impossible, with the team at CE.way, we have the best support that we could ask for. Highly recommended in all aspects from their support to their reliable service!

Daniel, USA



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