TPO: What you need to know

A chemical often found in gel-based nail products is to be banned in the EU & UK. HELENA BIGGS explores why & what this means for your existing products

Trimethylbenzoyl Diphenylphosphine Oxide (TPO) is a photo initiator that helps gel products to cure quickly under UV light. It can be found in concentrations of up to 5% in artificial nail systems and is “Removing the EU Cosmetics Regulation. used to maintain colour stability – but the European Commission is banning its use from 1 September 2025 (EU) and a date to be confirmed in 2026 (UK).

It’s the European Commission’s duty to ensure that cosmetics and personal care products sold in the EU are safe for use, and companies (as well as national and European regulatory authorities) have a responsibility to adhere to its rules. From 1 September 2025, it will be illegal to include TPO in any new cosmetics products manufactured and sold in the European Union. The ban does not apply to the use of existing products.

Why is the ban being introduced?

Francesca Rapolla, scientific affairs manager at the Cosmetic, Toiletry & Perfumery Association (CTPA), comments: “TPO received a harmonised classification as a Carcinogen, Mutagen, Reprotoxic (CMR) category 1B, under the EU Classification, Labelling and Packaging (CLP) Regulation. The EU Cosmetics Regulation (Article 15) prohibits the use of CMR substances in cosmetic products, unless specific exemption criteria are met. “An industry can voluntarily defend continued use of cosmetic ingredients that receive a harmonised classification as a CMR under EU CLP, by submitting thorough safety dossiers that meet the specific exemption criteria of Article 15 of the EU Cosmetics Regulation.

“In the case of TPO, the industry did not, and could not, defend the continued use of this ingredient in nail products, mainly because it could not demonstrate that there are no alternative ingredients. Therefore, TPO will be prohibited for use in cosmetics.”

What does this mean for nail products and manufacturers?

Many nail brands have anticipated the ban and reformulated their products to exclude TPO, using alternative photo initiators that provide similar results. “The removal of TPO from nail products doesn’t necessarily impact their performance, but they will require reformulation,” shares Doug Schoon, a scientific expert in the nail industry & founder of Schoon Scientific.

“Most of the concern over this ingredient involves using TPO in other applications that are not related to nail coatings, such as factories that manufacture printing inks and industrial adhesives. Removing TPO from nail coatings is not in response to problems with nail products containing this ingredient, but as a precautionary approach to consumer safety.”

Francesca Rapolla

"Removing TPO from nail coatings is not in response to problems with nail products containing this ingredient, but as a precautionary approach to consumer safety.”

Francesca comments: “Products containing TPO must be off shelves by 1 September 2025 in the EU and approximately late 2026 in the UK. Those responsible for placing nail products on the market will have to ensure compliance. This means not suppling products containing TPO by these dates, and instead providing products that have been reformulated without TPO.”

Doug adds: “When used improperly and skin contact is not avoided, TPO can cause skin sensitisation or allergic reactions in some individuals. However, adverse effects are rare when products are applied correctly by trained professionals.”

Nail professionals can still safely use products containing TPO until the ban takes effect, as the levels of TPO used in nail services are far below those considered harmful. “Brands can support the transition to products free from TPO by using safer photo initiators, providing education on proper application techniques for new formulas and clearly labelling TPO-free options,” Doug shares.

Action points

Nail professionals can check the SDS or labels of their products to identify whether they include Trimethylbenzoyl Diphenylphosphine Oxide, and ask questions to their product supplier. Doing this may offer clarification on ingredients or different methods of application for reformulated products.

Francesca comments: “Suppliers may be able to offer advice on how to manage leftover stock if applicable, or orders of new stock in preparation of the deadlines. Nail professionals may also wish to liaise with their product suppliers to understand if, or how, the reformulated products may perform differently from those containing TPO. 

“It is important to highlight that nail products containing TPO have not suddenly become unsafe for use on consumers. The CMR classification of TPO and the ban in the EU, and anticipated in the UK, is based on the hazardous properties that a substance might have under a ‘worst case’ situation, and does not take account of whether there is any risk associated with specific uses or exposures.”

 Francesca continues: “Nail professionals and consumers who have used and worn nail products that contain TPO, can be reassured that these products are still safe to use until the end of the transition period, when they will no longer be available. These products will have undergone a rigorous safety assessment by an expert assessor to ensure their safe use.”

 Insurance matters 

Scratch questioned ABT Insurance, a UK&I beauty insurance and membership provider, about the validity of insurance claims if products containing TPO are used after the sales ban comes into effect. Dave Horton, ABT director, supported by Stacie Price of Balens Specialist Insurance Brokers, comments: “Practitioners must follow current guidelines (as and when they develop or come into effect) in relation to the public policy directive, and ensure they are meeting all relevant UK/EU laws.

 “Some policies have wording regarding exclusion for criminal or malicious acts, so the use of a banned product where it goes against regulation could mean a claim is refused on that basis. The onus will be on practitioners to ensure they are prepared and informed for when the changes come into effect. It would also be prudent to exercise their own risk assessments and duties of care as to whether they wish to make any changes to the products they use, before the restrictions come into effect.” 

“In the case of TPO, the industry did not, and could not, defend the continued use of this ingredient in nail products, mainly because it could not demonstrate that there are no alternative ingredients. Therefore, TPO will be prohibited for use in cosmetics.”

Dave continues: “The policy will continue to respond where all terms and conditions of cover are being met and the client is practicing within all applicable UK/EU laws. No updates have been issued by insurers on this specific industry change or in relation to the specific substance at this time

Dave Horton