Can You Trust Your Ingredient List?
You read ingredient lists every day. You check for HEMA, look for allergen warnings, and perhaps choose products labelled "HEMA-free" for sensitive clients. But what if the ingredient list itself cannot be trusted? What if the monomers that actually cause sensitisation are present in the bottle but absent from the label?
This is not a hypothetical scenario. Multiple peer-reviewed studies and government investigations across five countries have now confirmed that mislabelling of nail products is widespread — and the problem goes far deeper than a few missing ingredients.
The Evidence: Five Countries, One Problem
Researchers and government laboratories in Finland, Germany, the Netherlands, Sweden, and the USA have all independently investigated nail product labelling. The findings are consistent — and alarming.
| Study | Country | Sample | Key findings |
|---|---|---|---|
| Sources: Peer-reviewed studies and government laboratory investigations from five countries | |||
| Suuronen et al. 2023 | Finland | 37 products | 100% had discrepancies between label and GC-MS analysis. HEMA undeclared in 8 of 20 products containing it. IBOA in 9 products — unlisted on all. |
| CVUA Freiburg 2011–2013 | Germany | Gov. lab analysis | Missing/incorrect labelling, prohibited substances (including banned MMA), high allergen levels, undeclared hydroquinone. |
| Steunebrink et al. 2023 | Netherlands | 394 products | 35% missing "For professional use only". 55% missing allergy warning. ~10% mislabelled. 45 different (meth)acrylates identified. |
| Dahlin et al. 2016 | Sweden | 1 UV nail polish | Product caused severe reactions. 7 of 8 patients allergic. Banned by Swedish Medical Products Agency. |
| Zhong et al. 2018 | USA | 17 salons, 35 products | Banned MMA detected in air at 15 of 17 salons. Not listed as ingredient in any product. |
The Dutch study is particularly striking because of its scale: 394 products from the online market. More than a third were missing the mandatory "For professional use only" warning. Under EU Regulation 2020/1682, products containing HEMA or Di-HEMA TMHDC above specified thresholds are illegal to sell to consumers. They are restricted to professional use only. Yet more than a third of the products surveyed were non-compliant.
Meanwhile, the German government investigation uncovered not only mislabelling but the presence of substances that should not have been in the products at all.
The Hidden Ingredient: Undeclared Hydroquinone
The German CVUA investigation revealed a category of labelling violation that most technicians would never think to look for: undeclared hydroquinone.
Hydroquinone is a polymerisation inhibitor — a chemical added to acrylate monomers during manufacturing to stop them from curing prematurely in the bottle. Without it, liquid monomers could begin to solidify during storage and transport. It is present in trace amounts, typically 100–200 parts per million (ppm), in the raw materials used to make gel nail products.
The EU Cosmetics Regulation permits hydroquinone in artificial nail systems at a maximum concentration of 0.02% (200 ppm) under Annex III. However, it must be declared on the label. The German investigators found products where hydroquinone was present but not listed — meaning technicians and clients had no way of knowing they were being exposed to a substance that is itself a known skin sensitiser.
Hydroquinone is not just a technical additive. It is classified as a skin sensitiser and is restricted in cosmetics for good reason. If a product contains it but does not declare it, you cannot make an informed choice about whether to use it — particularly on clients who may already be sensitised. The fact that it was found undeclared in government laboratory testing tells us that some manufacturers are either unaware of what is in their own raw materials, or are choosing not to disclose it.
The "Acrylates Copolymer" Red Flag
Independent ingredient analysis has uncovered another concerning pattern: gel nail products from multiple European brands whose ingredient lists include "Acrylates Copolymer" as a key ingredient — but fail to list the reactive monomers needed to make the product work.
Here is a quick chemistry lesson. A UV/LED-cured gel works because it contains reactive monomers — small molecules that link together (polymerise) when exposed to UV or LED light to form a hard coating. Without reactive monomers, the product cannot cure on the nail.
"Acrylates Copolymer" is something entirely different. It is a pre-formed polymer — the monomers have already reacted. It is a film-forming agent used in air-dry polishes and hairsprays. It does not cure under UV or LED light.
If a product claims to be a UV/LED gel, but its ingredient list shows Acrylates Copolymer without reactive monomers, then either: (a) the product contains reactive monomers that are not declared — a labelling violation, meaning you do not know what you are exposing yourself and your clients to — or (b) the product does not contain the monomers needed to function as a true UV gel, meaning it does not work as claimed. Either way, the ingredient list is misleading.
Check Your Own Products: What to Look For
Below are two example ingredient lists. Compare them against the products on your shelf. The key is to understand what types of ingredient should be present in a genuine UV/LED gel product.
Example A — What a genuine UV gel ingredient list looks like:
Di-HEMA Trimethylhexyl Dicarbamate [Reactive monomer]
Hydroxypropyl Methacrylate (HPMA) [Reactive monomer]
HEMA (2-Hydroxyethyl Methacrylate) [Reactive monomer]
Ethylene Glycol Dimethacrylate (EGDMA) [Crosslinker]
Hydroxycyclohexyl Phenyl Ketone [Photoinitiator]
Trimethylbenzoyl Diphenylphosphine Oxide [Photoinitiator]
Silica, CI 77891, CI 15850 [Pigment/filler]
This list makes chemical sense. It contains reactive monomers that will polymerise under UV/LED, photoinitiators to trigger curing, and standard cosmetic ingredients.
Example B — An ingredient list that raises questions:
Acrylates Copolymer [Pre-formed polymer — NOT a reactive monomer]
Ethyl Acetate [Solvent for air-dry polish, not UV gel]
Butyl Acetate [Solvent for air-dry polish]
Nitrocellulose [Film-former for conventional nail polish]
Acetyl Tributyl Citrate [Plasticiser]
CI 77891, CI 15850 [Pigments]
This list contains no reactive monomers and no photoinitiator. These are the ingredients of a conventional air-dry polish, not a UV/LED gel.
Your INCI Cheat Sheet
Keep this list handy when checking your products. These are the most common INCI names you will find in genuine UV/LED gel nail products:
| Category | INCI Name | Abbreviation | Role |
|---|---|---|---|
| Reactive monomer | 2-Hydroxyethyl Methacrylate | HEMA | Primary monomer |
| Reactive monomer | Hydroxypropyl Methacrylate | HPMA | Primary monomer |
| Reactive monomer | Di-HEMA Trimethylhexyl Dicarbamate | Di-HEMA TMHDC | Large monomer ("HEMA-free" products) |
| Crosslinker | Ethylene Glycol Dimethacrylate | EGDMA | Links polymer chains together |
| Crosslinker | Triethylene Glycol Dimethacrylate | TEGDMA | Links polymer chains together |
| Photoinitiator | Hydroxycyclohexyl Phenyl Ketone | Irgacure 184 | Triggers UV curing |
| Photoinitiator | Trimethylbenzoyl Diphenylphosphine Oxide | TPO | Triggers LED curing |
| Photoinitiator | Camphorquinone | CQ | Triggers visible light curing |
| Inhibitor | Hydroquinone | HQ | Prevents premature curing (max 0.02%) |
The quick test: Pick up any gel product from your shelf. Look at the ingredient list. Can you find at least one reactive monomer AND at least one photoinitiator from the table above? If yes, the ingredient list is at least consistent with a UV/LED gel product. If not, you should ask your supplier some questions.
Your 7-Point Label Literacy Checklist
- Does the product claim to be UV/LED-curing? If yes, you should see reactive monomers (names ending in "acrylate", "methacrylate", or "dimethacrylate") in the ingredient list.
- Is "Acrylates Copolymer" the main ingredient? This is a pre-formed polymer for air-dry polishes. If a UV gel lists this without reactive monomers, something does not add up.
- Is a photoinitiator listed? UV/LED gels need one to cure. No photoinitiator = no UV curing mechanism.
- Are the mandatory warnings present? Products containing HEMA or Di-HEMA TMHDC above specified thresholds must carry "For professional use only" and "Can cause an allergic reaction". Under EU Regulation 2020/1682, it is illegal to sell these products to consumers. If you see them available for home use without the required warnings, they are being sold in breach of EU cosmetics law.
- Is hydroquinone declared? If your product contains acrylate monomers, hydroquinone is almost certainly present as a stabiliser. It should be listed. If it is not, the manufacturer may not fully know or disclose what is in their formulation.
- Are ingredient names in proper INCI format? Vague terms like "acrylic resin" or "gel base" instead of standard INCI names are a warning sign.
- Can the supplier provide a Safety Data Sheet? A reputable manufacturer will provide an SDS that matches the label. If they cannot, or it does not match, ask why.
Not sure whether an ingredient list adds up? Copy the full ingredient list from a product label or Safety Data Sheet and paste it into an AI assistant such as Claude (claude.ai) or ChatGPT. Ask: "Is this a working gel or gel polish? Does this ingredient list contain the reactive monomers and photoinitiators needed for UV/LED curing?" It takes seconds and costs nothing. If the AI flags the same concerns described in this article, you have good reason to question that product.
Demand Better
The published research from five countries paints a clear picture: nail product labelling is not where it needs to be. Government laboratories have found prohibited substances, undeclared allergens, and hidden ingredients. Independent analysis has revealed products whose ingredient lists are chemically implausible. But the same research also shows us exactly what to look for.
- Ask questions. Request an SDS from your supplier. Ask them to confirm that their ingredient lists are based on independent laboratory analysis.
- Report non-compliance. In the UK, report misleading cosmetic labelling to your local Trading Standards office. In the EU, contact your national competent authority for cosmetics regulation.
- Support transparent brands. Choose suppliers who use proper INCI nomenclature, are open about raw material sourcing, and can answer technical questions about their formulations.
- Check your own products. Use the examples and cheat sheet in this article to review the products on your shelf today. If an ingredient list does not make chemical sense, that product deserves scrutiny — regardless of the brand name on the bottle.
Questions?
If you want help understanding your product labels, or if you have found something that does not add up and want a second opinion, get in touch. Our consultation is completely free of charge.
- Email: help@ikoniqnails.com
- WhatsApp: +49 160 649 7218
- Contact form: Contact Us
Based on peer-reviewed product analyses and government investigations from Finland, Germany, the Netherlands, Sweden, and the USA. Key references include Suuronen K, et al., Contact Dermatitis, 2024; CVUA Freiburg, 2013; Steunebrink IM, et al., Contact Dermatitis, 2024; Zhong L, et al., Int Arch Occup Environ Health, 2019. Full reference list available on request.
