Cosmetic Testing Explained

Testing cosmetic products is essential for anyone wanting to produce and sell cosmetics in the EU, it is required by law and applies to all; big manufacturers and small or independent brands.

Products must be registered on the Cosmetic Product Notification Portal (CPNP) before they are made commercially available and to register, products must have a Cosmetic Product Safety Report (CPSR) as a minimum.

Many manufacturers will want to add additional tests though. This can include tests for effectiveness and quality control.


The cosmetics industry is highly regulated – for good reason. Cosmetics are often used in close contact with the skin, therefore need to be composed of materials that aren’t harmful and are free from contaminants.

It’s rare, but contamination does happen and can come from a variety of sources. It can be the deliberate use of ingredients not approved for cosmetic use, or accidental contamination. Either way, scares linked to cosmetics make big news and are bad for business in the long run. Product recalls are costly and can cause irreparable damage to a business’s reputation.

Even after a ‘scare’ with a cosmetic product (many turn out to be false alarms), the damage has already been done and it may be difficult for a brand to restore their reputation.

Manufacturers of cosmetics also must consider how consumers will use their products (we all know that one person who has a lipstick that is ten years old!) and the length of time someone is likely to keep a product.

After so long, most cosmetics will start to deteriorate, or lose their effectiveness. Therefore, most products come with a little symbol on them to signify the amount of time a product should be kept after it is opened. Known as the period-after-opening symbol, or PAO symbol, it is a graphic symbol that identifies the useful lifetime of a cosmetic product after the package has been opened for the first time. It shows an open cosmetics pot and is used together with a number to signify months.


Cosmetic product testing can be broken down into three main areas; safety, efficacy and stability.

The first and most important of cosmetic testing is safety. Cosmetics such as makeup or lotions are applied directly to the skin, so it is of the utmost importance that products don’t contain any substances that may damage the skin, or cause health issues.

Microbiology tests are performed to ensure that the product is free from harmful levels of bacteria. The source of which can be accidental contamination during the manufacturing process or contaminated raw materials. This is usually done through batch testing – checking a selection of products before release. It’s often referred to as QC or sterility checks. For cosmetics and personal care products, this testing requires Enumeration of Aerobic Mesophilic Bacteria and Yeasts & Moulds and Determining Absence of Specified Organisms

In addition to the QC test, Preservative Efficacy Testing is carried out to determine that the preservative system of a product is working effectively. This test is carried out on products during the development stage.


The efficiency of a product or performance is tested to support marketing claims. Basically, does a product do what it is supposed to? There are laws and guidelines around product claims and a manufacturer can’t say a product will do something without having efficacy data to support the claim.

Finally, stability testing is carried out to determine what the shelf life of a product will be when released onto the market. It also determines if a product needs to be protected from any environmental conditions eg daylight

Many manufacturers select a minimum assessment of an elevated temperature eg 45°C compared to a 20°C in the dark control). Additional parameters, e.g. freeze/thaw, 5°C, 32°C, ambient daylight can be included according to the requirements or the type of product. Testing at 45°C, sometimes referred to as accelerated shelf life, provides an indication of a product’s performance over a long period at extreme temperatures. Freeze-thaw cycling is a controlled way of replicating the extreme cold night-time temperatures through to daylight temperatures often experienced when shipping products by air or sea or when products are stored in an unheated warehouse


Melbec Microbiology’s team of scientists has extensive expertise in the field of claim support and product release for the cosmetic and personal care industry.

Testing is carried out to assist with compliance with the Cosmetic Regulation (EC) 1223/2009 (which includes Preservative Efficacy, Stability and Batch Release testing) and with various stages of the product development process.

For more information or advice, please get in touch via our contact page. If you prefer to give us a call, you can reach us on 01706 214 492

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