Understanding the Risks of HEMA and TPO and Why You Should Avoid Them

Gel polish has transformed the nail care industry. Offering long-lasting and chip-resistant manicures, it's no wonder so many people enjoy it. Yet, behind this innovation lies complex chemistry, particularly regarding the roles of HEMA (2-Hydroxyethyl Methacrylate) and TPO (Benzoyl Peroxide). They have now been banned in the EU ( but not the UK yet), but what are they and why should I avoid them?

What is HEMA?

HEMA, or 2-Hydroxyethyl Methacrylate, is a standard ingredient in many gel polish formulations. This monomer serves as a crucial building block that helps form the polymer structure of the gel. When exposed to UV light, HEMA undergoes a chemical reaction that allows it to harden and bond effectively to the natural nail.

The choice of HEMA in gel polish stems from its ability to create a robust, durable finish. For instance, studies have shown that gels containing HEMA can last up to 14 days without chipping. However, it can also act as a sensitizer for some individuals. According to the American Contact Dermatitis Society, around 3.5% of the population may experience allergic reactions or skin sensitivities due to HEMA.

The Role of TPO in Gel Polish

TPO, or Benzoyl Peroxide, is a critical photoinitiator in gel polish formulations. Its main job is to start the curing process when the gel is exposed to either UV or LED light. Upon exposure, TPO decomposes into free radicals, triggering the polymerization of monomers, including HEMA.

Including TPO in gel polish formulations speeds up the curing process, leading to quicker application times and a stronger finish. For example, a gel polish containing TPO can cure in as little as 30 seconds under LED lights, compared to products without it, which may require 2 to 3 minutes. However, TPO can also cause sensitivity in some clients, so nail technicians must be aware of their clients' skin conditions and allergies.

The Importance of Understanding HEMA and TPO

Understanding HEMA and TPO is crucial for both me and you. Nail technicians need knowledge of these ingredients to provide informed recommendations and ensure client safety. Clients should recognize the potential for allergic reactions or sensitivities. For instance, if you are prone to dermatitis or have a history of skin sensitivities, it is wise to perform a patch test before applying gel polish containing HEMA or TPO.

Alternatives to HEMA and TPO

As the beauty industry advances, so do gel polish formulations. Several brands now offer HEMA-free and TPO-free options tailored for clients with sensitivities, including the brand I use INK London, who are reformulating their products to utilize different monomers and photoinitiators, providing comparable durability and finish without associated risks.

Most of the polishes I have are already HEMA free, and I have a small amount of HEMA and TPO free colours. HEMA and TPO are not yet banned in the UK but its likely they will be by September 2026.

HEMA and TPO free colours available at the time of writing

Final Thoughts

Understanding HEMA and TPO in gel polish formulations is essential for both nail technicians and clients. While these ingredients contribute to the durability and effectiveness of gel polish, awareness of their potential risks is equally important, especially for those with sensitivities. By staying informed and taking necessary precautions, both professionals and clients can enjoy the benefits of gel polish while minimizing risks.

As the industry continues to innovate, keeping up with ingredient safety and formulation changes will ensure a safer and more enjoyable nail care experience for all.