Monomer is a liquid chemical, primarily ethyl methacrylate (EMA), that is a foundational component for traditional acrylic nail enhancements. When mixed with a polymer powder, a chemical reaction called polymerization begins, creating a moldable paste. This substance is sculpted onto the nail or a nail tip and hardens as it is exposed to air. The resulting chemical bond forms a durable material, giving the enhancement its strength and longevity.
Reasons for Seeking Monomer Alternatives
The search for monomer substitutes is driven by two primary concerns: the intense odor and potential for allergic reactions. Traditional monomers containing ethyl methacrylate (EMA) emit a strong, pungent vapor that can be overpowering in salons or poorly ventilated areas. This smell is a result of the liquid’s volatile nature, which can cause headaches or respiratory irritation.
Beyond the smell, some individuals develop sensitivities or allergic reactions to chemicals within the monomer. These reactions can manifest as contact dermatitis, an inflammation of the skin with redness, itching, and blistering around the nail bed. A frequent culprit is 2-hydroxyethyl methacrylate (HEMA), a molecule that can penetrate the skin and trigger an immune response, leading to a demand for HEMA-free formulations.
Common Monomer Substitutes
One of the most direct substitutes is odorless monomer. This liquid acrylic is formulated with larger, less volatile molecules that do not evaporate as readily. While this reduces the smell, odorless systems have a much slower curing time. After hardening, they leave a sticky inhibition layer that must be wiped away with a solvent.
For those with specific sensitivities, HEMA-free monomers provide a targeted solution. These liquids are formulated without the HEMA molecule to reduce the likelihood of contact dermatitis. This offers a safer option for individuals who have previously experienced irritation. Their application and performance are similar to standard EMA monomers, minus the allergenic component.
Dip powder systems offer an approach that eliminates liquid monomer. This method involves applying a cyanoacrylate resin base coat to the nail, which is then dipped into a fine, colored acrylic powder. The process is repeated to build structure, and an activator liquid is applied to cure and harden the layers almost instantly.
Gel-based systems are another odorless, monomer-free category. Products like PolyGel and builder gels are viscous substances sculpted onto the nail. PolyGel has a putty-like consistency, while builder gels are more liquid and self-leveling. Unlike air-drying acrylics, these gel products do not harden until cured under a UV or LED lamp.
Comparing Application and Performance
The application and curing processes differ significantly among these systems. Traditional and odorless monomers use a liquid-and-powder technique that is sculpted and then air-dries. Dip systems use a resin base, a dip into powder, and a chemical activator for hardening. Gel systems are sculpted and remain pliable until cured for 30 to 120 seconds under a UV or LED lamp.
Regarding durability and flexibility, each system offers distinct characteristics. Traditional acrylics are known for their hardness and rigidity, making them very durable, and odorless acrylics offer similar strength. Gel systems are more flexible than acrylics, which can help prevent cracking under pressure. PolyGel is considered a middle ground, providing the strength of acrylics with the added flexibility of a gel.
The removal process also varies. Both traditional acrylics and dip powders are removed by filing the top surface to break the seal, followed by a 15 to 20-minute acetone soak to break down the product. Gels also require the top coat to be filed off before soaking. Hard gels are an exception, as they are non-porous and must be filed off entirely.