The differences between Bis-HEMA and HEMA in gel polish

As nail technicians utilizing professional gel products, it is vitally important for you to understand the various ingredients found within these formulations, particularly between Bis-HEMA and HEMA (2-Hydroxyethyl methacrylate). Both monomers are commonly utilised in producing nail enhancement materials such as gels and acrylics; however, there are distinct differences in their chemical structures, safety profiles, performance capabilities that must be understood for client safety as well as technician satisfaction.

Chemical Structure
Bi-HEMA boasts a larger and more complex molecular structure than its HEMA counterpart, significantly decreasing penetration into biological tissue as well as sensitization potential for nail technicians regularly exposed to these chemicals.

Allergic Reactions
HEMA can cause allergic reactions in some individuals, manifesting as contact dermatitis. Exposed repeatedly over an extended period, the risk of sensitisation or allergies increases significantly; on the other hand, bis-HEMA's larger molecular structure makes it less likely to provoke these types of responses and provides nail technicians with an alternative option for everyday use.

Vapor Pressure
HEMA has a higher vapor pressure than Bis-HEMA, meaning it evaporates more readily into the air and increases risk of inhaling HEMA vapors that could potentially cause respiratory irritation and other health concerns for nail technicians. On the contrary, Bis-HEMA's lower vapor pressure reduces inhalation exposure risk as well as associated health concerns for this profession.

Material Stability
HONA's Bis-HEMA's oligomer is a more complex structure which potentially contributes to increased crosslink density when curing, leading to an increase the propensity of the final polymer formation to include an increased conversion of the monomeric resins into the polymer formation

Some brands, like HONA, utilise Bis-HEMA as part of a long-chain oligomer to further increase safety. An oligomer consists of multiple monomer units linked together and can enhance performance and safety characteristics in nail products. A big point to make, which we will expand on in later articles

Bis-HEMA can be considered a safer option for nail technicians due to its lower potential for skin irritation and sensitisation, reduced inhalation exposure risk and overall material stability. Nonetheless, nail technicians must adhere to all necessary safety protocols and use PPE when working with any nail enhancement materials in order to mitigate potential risks.