Patch testing sits at the intersection of consumer safety and regulatory compliance in the European Union. As several major amendments to the EU Cosmetics Regulation take effect through 2026, brands, manufacturers and Responsible Persons need a clear view of where patch testing obligations begin and end.
From mandatory hair-dye warnings to the skin-sensitisation data underpinning every safety assessment. This article explains the different types of patch tests, what the rules actually require and how to stay compliant.
What “Patch Testing” Means in Cosmetics
The term “patch testing” covers two distinct concepts that are often confused. Understanding the difference is essential for compliance, because each is governed by different rules and each carries different obligations for the party placing a product on the EU market.
- Consumer patch testing (Allergy Alert Test) is a simple self-test that a consumer performs at home, typically 48 hours before use, to check for a delayed allergic reaction. In the EU this is closely tied to the mandatory warnings for oxidative hair dyes.
- Laboratory Patch test (or Human Patch test) evaluates how human skin tolerates a product or ingredient. It is conducted under the supervision of a qualified dermatologist and it evaluates skin tolerance on human volunteers.. It is conducted to support the Cosmetic Product Safety Report (CPSR) prior to a product being placed on the market, as well as to substantiate the claims intended for use on the product label.
Both feed into the same objective set out in Regulation (EC) No 1223/2009 – the EU Cosmetics Regulation, namely that every cosmetic product made available on the EU market must be safe for human health under normal and reasonably foreseeable conditions of use.
The Regulatory Foundation: Regulation (EC) No 1223/2009
Regulation (EC) No 1223/2009 is the cornerstone of cosmetic compliance in the EU. Three provisions are especially relevant to laboratory patch testing and allergy alert testing:
- Article 3 requires that every cosmetic product be safe for human health.
Article 10 requires the compilation of Cosmetic Product Safety Report – including the product’s toxicological profile and, where relevant, its potential to cause skin sensitisation – before the product is placed on the market. Depending on the product, this can be achieved through various methods, including a laboratory patch test conducted under the supervision of a dermatologist. Article 19 and Annexes III-VI set labelling and warning obligations, including the specific warnings for hair dyes concerning the potential for severe allergic reactions. While the Cosmetics Regulation does not provide any legally mandatory texts for additional instructions, it has been common practice for many years for manufacturers of hair colorants to apply hair dyes with warnings highlighting the need to perform an Allergy Alert Test before each colouring. Responsibility for compliance falls on the Responsible Person, who must hold an up-to-date Product Information File (PIF) and CPSR and ensure that all mandatory warnings appear correctly on the label.
Allergy Alert Testing for Hair Dyes: Mandatory Annex III Warnings
The most concrete legal touchpoint for patch testing cosmetics is oxidative (permanent) hair colour. Because ingredients such as p-phenylenediamine (PPD) and related aromatic amines are well-documented skin sensitisers, Annex III of the Cosmetics Regulation obliges manufacturers to print a standardised warning. The core wording, introduced by Regulation (EU) No 658/2013 and reinforced by later amendments such as Regulation (EU) 2020/1683, reads:
“Hair colourants can cause severe allergic reactions. Read and follow instructions. This product is not intended for use on persons under the age of 16. Temporary ‘black henna’ tattoos may increase your risk of allergy. Do not colour your hair if you have a rash on your face or a sensitive, irritated or damaged scalp, if you have ever experienced any reaction after colouring your hair, or if you experienced a reaction to a temporary ‘black henna’ tattoo in the past.”
Oxidative dyes containing PPD-type substances must additionally carry “Contains phenylenediamines. Do not use to dye eyelashes or eyebrows.” (or “Contains phenylenediamines (toluenediamines)”), a mixing-ratio statement. For professional-only products – a statement restricting use to professionals.
The 48-hour Allergy Alert Test
Building on these mandatory warnings, hair-dye manufacturers recommend that consumers carry out an Allergy Alert Test (also called a skin sensitivity test or patch test) 48 hours before every application. A small amount of the mixed product is applied to a discreet area of skin and left for a full 48 hours. Delayed contact allergy (allergic contact dermatitis) can take up to two days to appear, so cutting the time short risks missing a positive reaction. Because sensitisation can develop over time, the test must be repeated before each use, even with a previously tolerated product or brand.
Laboratory Patch Testing in Skincare and Other Cosmetics
EU law does not impose a general obligation on consumers to patch test skincare before use. Nevertheless, patch testing skincare is widely recommended good practice, particularly for leave-on products, products marketed for sensitive skin, products marketed for babies, intimate area products and formulations containing higher-risk actives (for example retinoids, alpha-hydroxy acids or high concentrations of essential oils or fragrances).
Additionally, a laboratory patch test is generally required to support certain claims, such as ‘dermatologically tested’ and ‘suitable for sensitive skin’, in line with the common criteria for cosmetic claims laid down in Article 20 of Regulation (EC) No 1223/2009 and Commission Regulation (EU) No 655/2013.
Why 2026 Is a Pivotal Year for Compliance
Several amendments converging in 2026 directly affect the allergen and sensitisation context that patch testing addresses. Even where a formulation is unchanged, labels, PIFs and CPSRs may need updating to remain compliant.
| Measure | What it changes | Key date |
|---|---|---|
| Regulation (EU) 2023/1545 | Expands labelled fragrance allergens from 26 to around 82. New allergens must be declared on the ingredient list where thresholds are exceeded. | 31 Jul 2026 (place on the market) 31 Jul 2028 (sell-through) |
| Implementing Decision (EU) 2025/1175 | Updated glossary of INCI ingredient names that must appear on labels. | 30 Jul 2026 |
| Regulation (EU) 2026/909 | New ingredient bans and restrictions (e.g. Triphenyl Phosphate prohibited; limits for Citral and others). | 1 Jan 2027 (place) 1 Jul 2028 (make available) |
| CMR omnibus amendments | Substances classified as carcinogenic, mutagenic or reprotoxic are prohibited or restricted. | Applicable from 1 February 2027 |
The fragrance-allergen expansion is the most directly relevant to patch testing cosmetics. Additional allergens exist precisely because they can trigger contact allergy, and clearer labelling helps sensitised consumers avoid them. Products placed on the EU market must carry the updated declarations by 31 July 2026, while products already on the market may generally be sold until 31 July 2028.
Compliance Checklist for Responsible Persons
To align with the 2026 requirements, the party placing a cosmetic product on the EU market should:
- Reassess fragrance-allergen content against Regulation (EU) 2023/1545 and update ingredient lists before 31 July 2026.
- Update INCI names to match the Implementing Decision (EU) 2025/1175 glossary by 30 July 2026.
- Refresh the CPSR so the allergens content is correctly assessed.. Update any CPSR older than three years.
- Audit formulations against the latest omnibus acts on CMRs and ingredients
How Obelis Can Help
As a European Authorised Representative and Responsible Person with decades of experience in cosmetics compliance, Obelis supports brands and manufacturers in navigating patch testing obligations, allergen labelling, CPSR review and the full set of 2026 amendments. From reviewing hair-dye warnings against Annex III to coordinating updated safety assessments in line with the latest SCCS guidance, our regulatory team helps ensure your products reach and remain on the EU market compliantly.
For tailored support, contact the Obelis regulatory team via https://www.obelis.net/contact/ .
Sources
1. European Commission — Regulation (EU) 2023/1545 (labelling of fragrance allergens). eur-lex.europa.eu/eli/reg/2023/1545/oj
2. European Commission — Regulation (EU) 2020/1683 (hair-dye warning updates). eur-lex.europa.eu/eli/reg/2020/1683/oj
3. European Commission — Regulation (EU) No 658/2013 (Annex III hair-dye warnings). eur-lex.europa.eu/eli/reg/2013/658/oj
4. SCCS — Notes of Guidance for the Testing of Cosmetic Ingredients and their Safety Evaluation, 12th revision (SCCS/1647/22). health.ec.europa.eu
5. European Commission — Implementing Decision (EU) 2025/1175 (glossary of common ingredient names / INCI). eur-lex.europa.eu
6. European Commission — Commission Regulation (EU) 2026/909 (amending Annexes II–V, ingredient restrictions). eur-lex.europa.eu
7. European Commission — Cosmetic products: internal market and safety overview. single-market-economy.ec.europa.eu