HEMA is an acronym for Hydroxyethyl Methacrylate. It is a small monomer that is a key ingredient in many gel nail polishes, gel extensions, and other nail enhancement products.
In its liquid state, HEMA is a small, reactive molecule. When it's exposed to UV or LED light, it undergoes a chemical reaction called polymerisation. The small HEMA molecules link together to form long chains. This forms a strong, hard, and durable plastic-like material. This hardened polymer is what gives gel nails their lasting wear, glossy finish, and chip resistance – which is why it is so popular.
What are the benefits of using HEMA in gel polish?
Strong Adhesion
HEMA in gel polish helps create a strong bond to the natural nail plate, which is essential for a long-lasting manicure. It is a small molecule that acts as a powerful adhesive that helps prevent chipping, peeling, and lifting. This is how gel polish solves common issues found when using regular nail polish.
Durability and Hardness
When HEMA in gel polish is exposed to UV or LED light, it undergoes a process called polymerisation. This is where its small molecules link together to form long chains. This creates a hard, durable, and chip-resistant coating on the nail. It's the reason gel nails can last for weeks without losing their glossy finish.
Versatility
HEMA is a versatile monomer that can be used in a variety of nail products, including gel polishes, builder gels, and acrylics. Its properties allow for the creation of different product consistencies and applications, from a thin gel polish to a thicker sculpting gel.
What makes HEMA a common allergen?
Small Molecule Size
HEMA is a small monomer, which means its molecules are tiny. This allows them to easily penetrate the skin and nail plate, especially when the product is uncured or if it makes direct contact with the skin.
Sensitisation
Repeated exposure to HEMA in gel polish on the skin can "sensitise" the immune system. Once sensitised, the body recognises HEMA as a foreign threat. From then on, any future exposure, no matter how small, can trigger an allergic reaction. This allergy is typically lifelong.
Misuse
The primary reason for allergies relating to HEMA in gel polish is improper application. A prime example is getting uncured gel on the skin, or under-curing due to a mismatch between the gel and the lamp. When the gel isn't fully cured, unreacted HEMA remains on the nail and can be a source of constant exposure.
Accessibility of at-home gel polish kits
The rise in popularity of DIY gel nail kits has led to an increase in allergic reactions. Many home users may not have the professional training to avoid skin contact or the correct UV/LED lamp to ensure that gels are completely cured.
Should I be concerned about HEMA in gel polish?
Generally speaking, not if you don't have a known allergy to HEMA. Other important factors to consider:
- Only use gel products containing HEMA if you are a fully qualified nail technician.
- You are using a setup and lamp designed and intended for the use of curing gel and builder gel polishes that contain HEMA.
- Avoid using unbranded consumer kits and gel nail products.
- Make sure your nail technician is fully qualified to apply gel nail products.
How to apply gel polish
Got further questions about HEMA?
Visit our HEMA FAQs.
