Ezmio Education

Gel polish is a special kind of nail product made with liquid acrylic molecules called monomers and oligomers. On their own, these ingredients are soft and sticky, but once exposed to UV or LED light, they go through a chemical reaction called polymerisation and turn into a solid plastic coating. That’s how gel becomes strong, glossy, and long-lasting on your nails.

How does liquid gel turn into a solid piece of plastic?

To truly understand how gel polish transforms from a sticky liquid to a rock-solid manicure, we need to dive into a process called polymerisation, and we’re going to do it using a pizza analogy.

In Science Terms:

Inside every bottle of gel polish is a carefully balanced blend of monomers, oligomers, and photo-initiators-  all suspended together in a smooth, liquid formula. Monomers are tiny, reactive molecules that act as the building blocks of the gel, while oligomers are short chains of pre-linked monomers that help give the product its thick, gel-like texture.

Floating among them are photo-initiators- small, specialised molecules (yes, also particles!) that remain inactive until exposed to UV or LED light. When the gel is placed under a nail lamp, the photo-initiators absorb the light energy and break apart into energetic fragments called free radicals. These free radicals then trigger the monomers and oligomers to start bonding together, setting off a powerful chain reaction known as polymerisation. This is the moment your gel begins to harden, transforming from a liquid into a solid, durable coating.

But to make this less intimidating… let’s turn it into cheese.

Imagine you're making a cheesy pizza.

Grated parmesan = monomers
These are tiny, separate particles that melt quickly and evenly, but on their own, they won’t give you that satisfying stretchy pull or solid texture.

Shredded mozzarella = oligomers
These are already grouped in soft strands- they’re thicker and stickier, and they give your pizza structure and meltability. They’re partially linked already.

The oven = your UV or LED nail lamp
Just like heat melts cheese and fuses it into the crust, UV light activates the photo-initiators in your gel. These act like the chemical "heat" that gets everything moving and bonding.

Step-by-Step Breakdown:

1. Before baking (before curing)
   The parmesan (monomers) is loose and crumbly. The mozzarella (oligomers) are in soft little strings. On the nail, the gel polish looks glossy and thick but has no real strength — just like an unbaked pizza.
   
2. The oven turns on (UV lamp is applied)
   The heat (UV energy) activates the photo-initiators in the gel — like the heat starting to melt your cheese. These initiators break apart and create energy fragments called free radicals that kick off the chain reaction.
   
3. Melting begins (polymerisation starts)
   As the UV light shines, the monomers (parmesan) start melting into and bonding with the oligomers (mozzarella). They fuse, flow, and stretch, just like cheese bubbling and connecting across the crust.
   
4. Structure forms (polymer chains grow)
   The individual particles form long, tangled chains, like the strings of cheese stretching across the whole slice. Once it cools (or finishes curing), the cheese has solidified, and your pizza has that perfect, gooey pull- except on your nails, this becomes a strong, solid surface.
   
5. Done cooking = proper cure
   A properly cured gel is like a fully baked pizza… firm, structured, with all the cheese melted and bonded into one delicious layer. No raw spots. No loose particles. Everything is connected.

Photoinitiators are molecules in gel products that absorb light and trigger the polymerisation (curing/hardening) process. Each photoinitiator is sensitive to a specific wavelength range of light. For curing to work properly, your lamp’s output needs to match that range.

To help you work out what type of lamp you need, we have broken down the most commonly used photoinitiators in gel products today and what type of lamp and wavelength you need to perfectly cure your gel polish.

A “proper cure” happens when 80–90% of the monomers/oligomers have linked into polymers. This ensures:

 Strength + long wear

 Minimal leftover allergens

 Less risk of chipping, lifting, or allergic reactions

A Proper Cure Requires 3 Key Things:

1. The Right Light
The UV/LED lamp must emit the correct wavelength. This light activates the photo-initiators in the gel, triggering the polymerisation process. Your lamp and gel must be compatible. Mismatched systems can result in under-curing.

2. The Right Time
Each gel formula has a recommended curing time. Cutting this recommended time short can leave the inside of the gel uncured, even if it feels hard on top. Always cure each layer for the full recommended time under the right lamp.

3. The Right Application Technique
Apply in thin, even coats, this allows UV light to penetrate through the entire layer. Thick coats block the light from reaching the bottom of the gel, leading to raw product left behind. Roll your gel polish before use (if the brand recommends it) to evenly distribute photo-initiators.

Uncured monomers stay trapped inside the gel. These can leach out over time or be released during removal (as dust or residue).

Repeated exposure can lead to gel allergies, skin irritation, or poor nail health.

You may also see lifting, chipping, or dullness in your mani.

When we talk about a “proper cure” in gel products, we’re usually referring to 80–90% polymerisation. That means 80–90% of the reactive ingredients, the monomers and oligomers, have fully bonded into long, stable chains called polymers.

This is the industry standard for a safe, durable manicure, but even in the best-case scenario, there’s always a small percentage of uncured molecules left behind. These usually remain trapped inside the hardened gel layer and don’t cause problems until the gel is filed, buffed, or soaked off.

When you file or buff off cured gel, you're breaking the hardened polymer chains into tiny dust particles, and those particles can carry traces of uncured monomers or oligomers from deep within the layer.

If you inhale this dust over time, it may:

Irritate your lungs or sinuses
Trigger allergic reactions (especially if you’re sensitive to acrylates)
Increase risk of long-term sensitivity to gel products

This is why it’s essential to:

Always wear a dust mask when removing gel

Use a ventilated space or dust extractor

File gently, and never over-buff

Soaking = Direct Skin Contact with Residual Monomers

If you remove your gel by soaking, especially with acetone or a gel remover:

The topcoat breaks down, exposing deeper layers of the gel

Uncured monomers and photo-initiators can leach out into the soaking liquid

Your skin is now sitting in that liquid, absorbing small amounts of these raw, reactive chemicals

Even though you may not feel anything right away, repeated exposure can:

Sensitise the skin

Cause redness, itching, or allergic reactions over time

Weaken your tolerance to nail products (even with professional systems)

Why This Happens — Even When You Cure Properly

Even if you follow all the right steps:

Use the correct lamp, cure for the full time and apply in thin, even coats...

Gel chemistry is complex. No system achieves 100% polymerisation, because the light doesn’t always reach every molecule perfectly, especially in deeper or thicker parts of the gel.

This is normal and expected, but it’s why removal is just as important as application when it comes to safety.

Always use IPA (Isopropyl Alcohol) NOT acetone, when working with gel polish.

After curing most gel polish (unless you’re using a no-wipe top coat), you’re left with a sticky layer on top. This is called the inhibition layer, and it forms because oxygen interferes with the final stage of curing, leaving a slightly tacky surface.

To remove this sticky layer, you should use IPA (isopropyl alcohol), not acetone.

IPA is a gentle solvent that effectively dissolves and lifts the inhibition layer without affecting the cured gel underneath.

It preserves your manicure, leaving a smooth, glossy, fully sealed finish.

It’s ideal for surface cleaning during gel application, as well as for removing any uncured gel from skin.

Why You Shouldn’t Use Acetone:
Acetone is far too harsh for surface cleaning.

It doesn’t just remove the inhibition layer, it can break down the cured gel, causing:

A weakened or dull finish

Premature chipping or lifting

Loss of shine or damage to the gel’s surface texture

Think of it like using paint thinner on a finished wall, it doesn’t just clean, it can ruin what you just perfected.

If the Gel Is Still Uncured:
Uncured gel contains active monomers and photo-initiators, which can irritate the skin or trigger allergies over time.

What to do:
Wipe it off immediately using a lint-free wipe soaked in IPA.

Wash the area with soap and water to remove any residue.

Apply moisturiser if the skin feels dry.

Don’t use acetone, it won’t neutralise uncured gel and can actually spread it around, increasing the risk of skin exposure.

If the Gel Has Already Cured on the Skin:
Cured gel is no longer chemically active, but it’s still best not to leave it on your skin.

What to do:

Gently lift or peel it off. Cured gel on skin usually flakes easily.

It is important to NOT cure gel that has touched the skin. This can trap reactive ingredients against your skin, increasing the risk of contact dermatitis or allergic reactions.

No. IPA helps wipe away gel from the skin, but it does not deactivate monomers.

Here’s why:

IPA is a solvent, not a neutraliser.

It lifts and removes the gel from the surface but doesn’t chemically stop monomers from being reactive.

Any monomers left behind can still cause irritation, dryness, or allergies.

Best Practice:
Wipe the area with IPA to lift the gel.

Follow up with soap and water to remove any residue.

If gel touches the skin, remove it before curing. Even a little can cause long-term sensitisation.

Yes! Only after the manicure is complete and cured. Washing too early (before curing) can affect adhesion. But once cured, washing helps remove dust and any residue left on your hands.

1. Avoid skin contact with uncured gel. Monomers can cause irritation or allergies.
   
2. Wipe off mistakes immediately with Isopropyl Alcohol, then wash skin with soap and water.
   
3. Always follow our curing system instructions. Do not mix gels and lamps from different systems.
   
4. Use thin, even layers to let the light reach all the way through.
   
5. Wear nitrile heavy duty gloves and avoid skin contact when wiping inhibition layers. They contain the highest concentration of uncured product.