Let’s stir up some magic in the lab with today’s hot topic: what cosmetic tests are legally required before you can sell your product in Europe.

You’ve got your formula idea, maybe a balm, a serum, or a rich face cream, and you’re ready to turn it into your brand’s first signature product. But then the reality of regulation hits: what does the law actually require? Do you really have to do tests? How much do they cost? And how complicated is it, really?

Don’t panic. Cosmetic compliance may sound intimidating at first, but it follows a very clear and logical structure. Once you understand the purpose behind each test, the process becomes far less mysterious.

This guide breaks down the essential cosmetic tests required before placing a cosmetic product on the EU and UK markets and explains why they matter, when they’re mandatory, and what happens if you skip them.

Why Cosmetic Testing Matters

Before you can sell a cosmetic product anywhere in the European Union or the United Kingdom, you must comply with Regulation (EC) No 1223/2009 (and its UK equivalent).

This regulation ensures that all cosmetic products are safe for human health, properly labelled, and supported by scientific data. It’s not just bureaucracy, it’s a legal and ethical safeguard for both consumers and your brand’s credibility.

Testing isn’t about red tape. It’s about proof: that your formula is stable, microbiologically safe, and non-toxic when used as intended.

1. The Stability Test – Proof That Your Product Performs Over Time

What It Is and Why It’s Mandatory

The stability test checks whether your product maintains its texture, colour, scent, pH and performance over time and under different conditions. A stable product remains consistent throughout its shelf life and period after opening (PAO). It demonstrates that your formulation won’t degrade or separate, and that your packaging protects it effectively.

What the Stability Test Evaluates

• Physical and chemical stability (texture, viscosity, colour, pH)

• Compatibility between formula and packaging

• Resistance to temperature and light

• PAO or expiry date determination

Typical Duration and Method

ALL brands have to run a 12-week accelerated stability test, storing samples at 45°C, room temperature, and refrigeration to simulate long-term conditions. Complementary tests may include freeze–thaw cycles and light exposure.

Once completed, your toxicologist uses this data to validate the claimed shelf life and packaging compatibility.

Cost Estimate

For small businesses, stability testing costs roughly €300 to €600, depending on product complexity and the laboratory.

2. The Challenge Test (Preservative Efficacy Test)

When It’s Required

The challenge test, also known as the Preservative Efficacy Test (PET), is mandatory for all water-containing formulations such as emulsions, gels, creams, or toners.

If your product contains no water (for example, balms, oils, or butters), you don’t have to perform the PET. However, your toxicologist must include a written justification in the PIF explaining why it’s not required. 

What the Challenge Test Does

The PET verifies that your preservative system is strong enough to prevent microbial contamination throughout the product’s lifespan. During the test, laboratories intentionally introduce bacteria, yeasts, and moulds into your formula, then measure how effectively the system neutralises them over time.

This ensures that your customers stay safe even when products are stored in bathrooms or handled with wet fingers.

Typical Cost and Duration

On average, a challenge test costs between €200 and €500 per product and takes 4–6 weeks to complete.

It’s usually performed according to ISO 11930, the European standard for preservative efficacy testing.

What Happens If You Skip It

Without a PET, your safety assessor cannot confirm microbiological safety and thus, will not be able to finalise and validate your CPSR (safety assessment), rendering it impossible for you to sell your cosmetics legally. Non-compliant products risk withdrawal from the market, fines, and reputational damage.

3. The Cosmetic Safety Assessment (Toxicological Evaluation)

The Heart of Your Product Information File

The safety assessment, also called the CPSR (Cosmetic Product Safety Report), is the most crucial and legally binding document for any cosmetic sold in the EU or UK.

It must be written and signed by a qualified toxicologist or safety assessor registered in the EU or the UK.

What It Includes

The assessor reviews:

• Your full INCI list and ingredient concentrations

• All supporting toxicological data for each ingredient

• Results of stability and microbiological tests

• Packaging compatibility

• Intended use and application area (face, body, lips, etc.)

• Target population (e.g., babies, pregnant women)

• And more

Once approved, this report forms the final section of your Product Information File (PIF) and is required to register your product on the CPNP (Cosmetic Products Notification Portal).

Typical Cost

On average, it costs between €150 and €600 depending on the number of ingredients and the complexity of the formula.

Why It Matters

Without a signed CPSR, your product is not legally marketable. Retailers, distributors, and online marketplaces within the EU are entitled to ask for proof of compliance and without it, they can reject or remove your listings.

4. Packaging Compatibility and Labelling Checks

While not at all classified as “tests,” packaging and labelling reviews are integral to compliance.

Packaging Compatibility

Your packaging must not leach substances into the formula or react with it. Compatibility is assessed during the stability study, but if your product contains volatile or reactive compounds, additional packaging tests may be necessary.

Labelling Requirements

Your label must include:

• Product name and function

• Nominal content (weight or volume)

• Batch number

• Country of origin (if imported from outside the EU)

• Shelf life (PAO or expiry date)

• Responsible person and address

• Ingredient list in INCI format

• Any relevant warnings or precautions and directions of use

Neglecting labelling details is one of the top compliance mistakes for small brands. A simple pre-launch review can save you reprinting costs later.

5. The Product Information File (PIF)

Your Central Compliance Document

The Product Information File is the core dossier that proves your cosmetic meets all regulatory standards. It must be stored (digitally or physically) within the EU or UK for ten years after the last batch is placed on the market.

Your PIF includes:

• Formula (INCI and exact percentages)

• Method of manufacture and GMP declaration

• Results of all mandatory tests (stability, PET, compatibility)

• Safety assessment (CPSR)

• Packaging and labelling details

• Claims substantiation (if relevant)

When inspectors review your brand, they start with the PIF. Having it clean, structured, and accessible shows professionalism and ensures fast approvals.

6. CPNP Registration and Notification

Once your product is fully tested and assessed, the next step is to register it on the CPNP (Cosmetic Product Notification Portal).

This online portal centralises safety information across the EU for all cosmetic products and ensures authorities can quickly trace product data in case of adverse reactions.

In the UK, brands must register via the OPSS Portal (Office for Product Safety and Standards).

Both portals require:

• Responsible person details

• Product category and function

• Label and image upload

• Safety assessor’s name and CPSR date

Registration is free, but all documents must be ready beforehand.

What Happens If You Skip a Test or Document

Many new founders underestimate compliance. Unfortunately, selling an untested cosmetic is not a “grey area”, it’s a direct violation of EU law.

Authorities can:

• Demand withdrawal of the product

• Impose fines

• Suspend your sales

• Request public recall if safety is compromised

Beyond the legal risk, non-compliance erodes consumer trust. In the beauty world, your brand’s credibility is built on transparency and safety.

How MB Cosmetics Lab Simplifies Compliance

If regulatory paperwork makes your head spin, you’re not alone. Many founders delay launch simply because they don’t know where to start.

At MB Cosmetics Laboratory, we simplify the process by handling everything for you, from formulation to legal documentation.

When you delegate your project to us, you receive:

• Full formulation development

• Lab samples manufacturing for lab tests

• Coordinating Stability test and Challenge test (where applicable)

• Coordinating CPSR finalisation

• Complete PIF preparation

• A free labelling guide and free label review

• Personalised support through every step, in plain language

You stay focused on creativity and brand development while we handle the scientific and regulatory side.

Here are my final thoughts

If you remember one thing, let it be this: testing is not optional. It’s the backbone of product quality and consumer safety.

• Always validate stability before anything else.

• Never skip preservative efficacy testing for water-based formulas.

• Make sure your toxicologist signs off your CPSR before launch.

• Keep your PIF updated with every formulation or packaging change.

• Register your products on the CPNP or SCPN (OPSS) portal before sales.

Compliance isn’t a roadblock, it’s what makes your brand credible, trustworthy, and ready for scale. Once you master these essentials, you’ll navigate testing and documentation with confidence.

Here’s to formulas that work and brands that thrive!

From my lab to yours,

Rose