HEMA and TPO - what’s the difference and why does it matter?

In a topic that’s been widely talked about recently on many social media platforms, you may or may not have come across the terms HEMA and TPO, especially in phrases like “HEMA and TPO-free builder gel.” But what exactly are HEMA and TPO, and why does it matter? Let’s break it down.

What is HEMA?

HEMA stands for Hydroxyethyl Methacrylate. It’s a chemical ingredient commonly used in nail products such as builder gels, gel polishes, and acrylic systems. 

HEMA is primarily responsible for helping the product adhere to your natural nail. Without it, many gels wouldn’t adhere as effectively or last as long.

In short, HEMA is one of the key ingredients that makes builder gel reliable and long-lasting.

Why would a product be HEMA-Free and is it dangerous?

While HEMA is highly effective when formulated correctly in a professional product, if it is added in higher concentrations than recommended, it can cause sensitivity or allergic reactions in some people, especially with repeated exposure.

HEMA isn’t dangerous when used safely and correctly. At present, it’s still widely used in professional nail products and considered safe under proper conditions.

Problems tend to arise when:

• The gel touches the skin instead of staying on the nail plate

• The product is not fully cured

• There is repeated, long-term exposure in high concentrations

  
  

When applied carefully and cured properly in the correct lamp, most people can tolerate HEMA-based products without issues.

What is TPO?

TPO stands for Trimethylbenzoyl Diphenylphosphine Oxide. It’s a completely different and separate ingredient to HEMA, with a different function. 

TPO is a photoinitiator, which is used to kick start the gel ‘curing’ process under a UV or LED lamp.

Why would a product be TPO-free and is it dangerous?

TPO has already been banned in cosmetic products in the EU (since 1 September 2025) and the UK will be following EU regulations in a phased approach; products containing TPO must not be on the market from 15 August 2026 and must not be available after 14 February 2027.

The Cosmetic, Toiletry and Perfumery Association (CTPA) website has recently published a comprehensive update on the ban. You can read more about this here: 

Ban of TPO (gel nail ingredient) in the EU and GB

It’s important to note that, even with the changes to regulations, products containing TPO are still safe and legal to use.