“HEMA-free” and “TPO-free” now appear on many gel nail products, but the two labels describe different ingredients and different questions. Understanding the distinction makes it easier to have a useful conversation with your nail technician without turning a manicure into a chemistry lesson.
What is HEMA?
HEMA—2-hydroxyethyl methacrylate—is one member of the methacrylate family used in some gel and artificial-nail systems. The concern is not that every person who wears a HEMA product will develop a problem. It is that uncured product touching the skin can contribute to sensitisation, after which later exposure may trigger allergic contact dermatitis.
Rules retained in UK law restrict HEMA and Di-HEMA TMHDC in nail products to professional use and require an allergy warning. “HEMA-free” means that particular ingredient is not in the formula; it does not mean “acrylate-free”, “allergy-proof” or suitable for someone with a known acrylate allergy.
What is TPO?
TPO—diphenyl(2,4,6-trimethylbenzoyl)phosphine oxide—is a photoinitiator that helps some gel coatings cure under a lamp. Great Britain added TPO to its prohibited cosmetic substances in 2026. The manufacturing restriction came into force on 15 August 2026, with transitional provisions for products already placed on the market before that date. Northern Ireland follows the EU cosmetics regime, where the prohibition has applied since 1 September 2025.
That regulatory timeline is why “TPO-free” is increasingly visible on new-generation gel systems. A salon should be able to identify the brand and product system being used and follow the supplier’s current instructions.
What matters during an appointment?
- Uncured gel should not be painted onto the surrounding skin.
- The lamp, exposure time and coating system should be used as the manufacturer specifies.
- Tell your technician about previous itching, swelling, blistering or nail lifting after gel, acrylic, dental or adhesive products.
- If you have a diagnosed acrylate allergy, seek medical guidance rather than relying on a “free-from” label alone.
A thoughtful gel service is a combination of suitable products, careful application, correct curing and honest communication. Ingredient labels are useful—but technique and professional judgement matter too.
Sources and further reading
UK Statutory Instrument 2026 No. 23 · HEMA and Di-HEMA professional-use conditions · British Association of Dermatologists
This article is general information, not medical advice. If you have pain, swelling, a persistent rash or an unusual change to a nail, speak to a pharmacist, GP or dermatologist.