HPMA (CAS 27813-02-1) is not specifically restricted in the EU or the US. It is classified as a skin sensitiser (H317) and should be handled with the same skin-contact caution as HEMA.

HEMA, HPMA & TPO in Nail Products: EU & US Rules (2026) | Nailspiracy Library

Nailspiracy Library · Standards & Safety

Ingredient Regulation Guide

HEMA, HPMA & TPO in nail products: what the EU and US actually allow

Q: Is HEMA banned in the EU?

No. HEMA (CAS 868-77-9) is restricted, not banned, in the EU. Since 3 June 2021 it may only be used in professional nail products, which must carry the warnings 'For professional use only' and 'Can cause an allergic reaction' under Regulation (EU) 2020/1682.

Q: Is TPO still legal in the US?

Yes. As of June 2026 there is no US federal ban on TPO. A TPO-containing gel can be sold in the US but not in the EU.

Q: Does HEMA-free mean the product is hypoallergenic?

No. HEMA-free only means the product does not contain HEMA (868-77-9). Many HEMA-free gels use HPMA (27813-02-1), a related methacrylate with a similar skin-sensitisation risk, so a HEMA-free product is not automatically allergen-free.

A plain-language, citable reference to the methacrylate-era ingredients every gel brand is now judged on - who sets the rules, what's banned, what's restricted, the permitted levels, the TPO-substitute question, and how to stay compliant.

Published by Nailspiracy Reviewed June 2026 Reading time ~13 min Scope EU & United States

Key facts at a glance

HEMA (CAS 868-77-9) is restricted, not banned, in the EU. Since 3 June 2021 it may only be used in professional nail products, which must be labelled "For professional use only" and "Can cause an allergic reaction" (Regulation (EU) 2020/1682).
TPO (CAS 75980-60-8) is banned in EU cosmetics from 1 September 2025 after being classified as a reproductive toxicant (CMR 1B). No safe level applies; it must be removed from the EU market.
The usual TPO replacement, TMO (CAS 270586-78-2), is a different substance that the EU's scientific committee assessed as posing no consumer health risk in nail products at use levels up to about 5%.
HPMA (CAS 27813-02-1) is not specifically restricted in either the EU or the US, but it is a recognised methacrylate skin sensitiser - "HEMA-free" does not mean "sensitiser-free."
The United States bans almost nothing here federally. HEMA, HPMA and TPO are permitted; the one methacrylate widely prohibited is MMA (methyl methacrylate), restricted by the FDA and banned in 30+ states.
Nailspiracy formulates its gel range without HEMA (868-77-9) and without TPO (75980-60-8), and discloses full CAS-level composition on every Safety Data Sheet.

If you make, sell, or use UV/LED gel products, four ingredients now define whether a formula is compliant, sellable, and safe to market: HEMA, HPMA, TPO and MMA. They are constantly confused with one another, yet each has a different chemistry, a different risk, and a completely different legal status. This guide separates them and states exactly what the European Union and the United States require, as of June 2026.

01The four molecules that matter

All four belong to the methacrylate family, but they are not interchangeable. The single most common compliance mistake in the nail industry is treating "methacrylate" as one thing.

HEMA 2-Hydroxyethyl methacrylate · CAS 868-77-9 EU: restricted US: allowed

The workhorse monomer that gives gel its adhesion. It is a weak-to-moderate skin sensitiser - the leading cause of gel-related allergic contact dermatitis when it touches the skin around the nail. It is restricted in the EU to professional use and permitted in the US.

HPMA Hydroxypropyl methacrylate · CAS 27813-02-1 EU: allowed US: allowed

A close chemical cousin of HEMA, often used as a HEMA replacement. It carries the same allergy concern (classified H317 "may cause an allergic skin reaction" and H319) but is not named in any EU or US restriction. A product can be truthfully "HEMA-free" and still contain significant HPMA.

TPO Diphenyl(2,4,6-trimethylbenzoyl)phosphine oxide · CAS 75980-60-8 EU: banned US: allowed

A photoinitiator - the ingredient that makes gel cure under a lamp. Reclassified as a reproductive toxicant (CMR category 1B), which automatically triggered its prohibition in EU cosmetics from 1 September 2025. Still legal in the US.

MMA Methyl methacrylate · CAS 80-62-6 US: prohibited (de facto) EU: not named

The old, cheap acrylic monomer associated with nail damage and severe reactions. The US FDA removed 100% MMA nail products in the 1970s and considers it "poisonous and deleterious"; it is prohibited in 30+ US states. Replaced industry-wide by EMA (ethyl methacrylate).

The takeaway: "free-from" claims are only meaningful when tied to a specific CAS number. "HEMA-free" (868-77-9) and "TPO-free" (75980-60-8) are precise, verifiable claims. "Methacrylate-free" is almost never true of a gel and should be avoided.

02Where the rules come from

Understanding who issues a rule tells you how binding it is and how fast it can change.

European Union

Regulation (EC) No 1223/2009 - the EU Cosmetics Regulation, the master law for every cosmetic sold in the EU. Its Annex II lists prohibited substances; Annex III lists restricted ones.
SCCS (Scientific Committee on Consumer Safety) - the EU's independent scientific panel. It reviews ingredients and publishes opinions that the European Commission turns into law.
ECHA (European Chemicals Agency) - runs the CLP Regulation (EC) No 1272/2008, which assigns hazard classifications (such as the CMR 1B status that doomed TPO).
The European Commission - converts SCCS opinions and CLP classifications into binding "Omnibus" amendments to the Annexes.

United States

FDA, under the Federal Food, Drug, and Cosmetic Act (FD&C Act) and the 2022 MoCRA modernisation - regulates cosmetics, but does not pre-approve cosmetic ingredients and has banned very few outright.
CIR (Cosmetic Ingredient Review) - an industry-funded expert panel that publishes safety assessments; influential but not law.
State cosmetology boards - where most real nail bans live (for example, MMA prohibitions).
California DTSC - uses the Safer Consumer Products programme to target specific ingredients (it moved on MMA above 1,000 ppm in 2024-2025).

Structural difference: the EU regulates by pre-market substance lists (a substance is allowed only on the terms set in the Annexes), while the US regulates mostly after the fact and largely at state level. This is why an identical gel can be illegal in Berlin and unremarkable in Texas.

03EU regulation in detail

HEMA & Di-HEMA TMHDC - restricted (Annex III)

After cases of sensitisation reported in several member states, the SCCS concluded in 2018 that HEMA and Di-HEMA TMHDC are weak-to-moderate sensitisers that are safe only when kept to the nail plate and away from surrounding skin. The Commission acted through Regulation (EU) 2020/1682, adding both to Annex III. The terms:

Permitted in professional nail products only; any other cosmetic use is prohibited.
Two mandatory warnings on pack: "For professional use only" and "Can cause an allergic reaction."
Effective 3 June 2021 (placing on the market) and 3 September 2021 (making available).

There is no numeric percentage cap in the regulation itself. The control is the professional-use restriction plus the warnings, with the product supplied "ready for use." (In practice, professional formulations run up to roughly 35% HEMA, but that figure is an industry norm, not a legal ceiling.)

TPO - banned (Annex II)

TPO received a harmonised CMR category 1B classification (suspected of damaging fertility/the unborn child). Under the Cosmetics Regulation, a CMR 1B substance is automatically prohibited unless specifically exempted - and no exemption was granted. TPO was added to Annex II by Commission Regulation (EU) 2025/877 (the "Omnibus VII" act), and from 1 September 2025 any cosmetic containing it can no longer be sold in the EU, regardless of concentration or when it was bought. The European Commission has published a dedicated TPO in nail products Q&A confirming that professionals may not use up existing stock after that date.

TPO substitutes and the 5% question

Removing TPO means changing the photoinitiator. The most common substitute in professional gels is TMO - Trimethylbenzoyl ditolylphosphine oxide (CAS 270586-78-2) - which is a different substance from the banned TPO (75980-60-8). The EU's Scientific Committee on Consumer Safety has assessed acylphosphine-oxide photoinitiators of this type and found no consumer health risk at nail-product use levels up to around 5%. That 5% figure is the practical reference point most formulators work to.

Two things to watch:

TMO has no harmonised EU classification. That means suppliers self-classify it, and they don't always agree - one factory may label TMO as a suspected reproductive toxicant (H361) while another labels the same substance, at a similar percentage, as not classified. The difference is classification philosophy, not different chemistry.
"TPO-free" only confirms the absence of 75980-60-8. It does not tell you which photoinitiator replaced it or at what level. Always read the SDS for the actual photoinitiator and its percentage.

This is exactly why Nailspiracy states the photoinitiator and its CAS number explicitly on every Safety Data Sheet - so a "TPO-free" claim can be checked against the real formula rather than taken on trust.

HPMA - currently unrestricted

HPMA is not listed in Annex II or Annex III. It is legal in EU consumer and professional nail products with no special labelling. It is, however, a known sensitiser, and brands relying on it as a "HEMA-free" substitute should expect continued scientific scrutiny of the wider methacrylate group.

04US regulation in detail

The US has no federal ban on HEMA, HPMA or TPO. Cosmetic ingredients are not pre-approved, and the FDA's enforcement focuses on misbranding and demonstrable harm rather than ingredient lists.

The one real prohibition: MMA

The FDA removed 100% MMA nail products from the market through court action in the 1970s and still calls liquid MMA monomer "poisonous and deleterious" in fingernail preparations.
More than 30 states prohibit MMA in nail services; California has banned even possession in licensed salons since 1994 (Title 16, §989).
California's DTSC moved in 2024-2025 to list nail products containing MMA above 1,000 ppm as a Priority Product.
EMA (ethyl methacrylate) is the accepted acrylic monomer in its place.

HEMA, HPMA and TPO in the US

All three remain legal in US nail products. There is no mandatory "professional use only" label for HEMA as there is in the EU, and TPO - banned in Europe - can still be sold in the United States. This transatlantic gap is the single most important thing for a brand selling in both markets to understand: an EU-compliant formula is almost always US-compliant, but a US formula is frequently not EU-compliant.

05EU vs US, side by side

Ingredient	CAS	European Union	United States
HEMA	868-77-9	Restricted - professional only + 2 warnings (Reg. 2020/1682)	Allowed - no federal restriction or warning
Di-HEMA TMHDC	-	Restricted - same terms as HEMA	Allowed
HPMA	27813-02-1	Allowed - not listed (known sensitiser)	Allowed
TPO	75980-60-8	Banned from 1 Sep 2025 (CMR 1B)	Allowed - no federal ban
TMO (TPO substitute)	270586-78-2	Allowed - assessed safe ≈5%; no harmonised classification	Allowed
MMA	80-62-6	Not specifically named in nail law	Prohibited de facto (FDA + 30+ states)
EMA	97-63-2	Allowed	Allowed - accepted acrylic monomer

06Permitted concentrations

"What percentage is allowed?" is the most-asked question - and the answer is more nuanced than a single number, because the EU restriction on HEMA is a use restriction, not a concentration cap.

Ingredient	EU permitted level	US permitted level	Note
HEMA	No numeric cap; professional-use only + warnings	No federal cap	Industry norm ≈ up to 35%; keep off surrounding skin
HPMA	No specific cap	No specific cap	Sensitiser; treat like HEMA in practice
TPO	0% - prohibited	No federal cap	Banned regardless of level since 1 Sep 2025
TMO (TPO substitute)	No formal cap; ≈5% assessed safe by SCCS	No federal cap	Not the banned TPO; suppliers self-classify differently
MMA	Not specifically capped	Effectively 0% (CA: >1,000 ppm targeted)	Use EMA instead

Important: a concentration being legal does not make it advisable. The dominant real-world harm in this category is allergic contact dermatitis from skin contact with HEMA/HPMA - a risk driven by application technique and skin contact, not just by the number on the label.

07How to work with the rules

If you are a brand or distributor

Decide your market first. EU-bound product must clear Annex II/III; build to the stricter EU standard and the US takes care of itself.
Verify every claim against a CAS number. "HEMA-free" must mean no 868-77-9; "TPO-free" must mean no 75980-60-8. Cross-check the Safety Data Sheet composition, not the marketing copy.
Don't let "HEMA-free" imply "allergen-free." If a formula replaces HEMA with HPMA, say so honestly; the sensitiser risk is similar.
Confirm photoinitiators are TPO-free for the EU. Check that the TPO substitute (e.g. TMO 270586-78-2, BAPO 162881-26-7, TPO-L 84434-11-7) is the one actually used, at what level, and how each supplier classifies it.
Keep a current, CAS-level SDS for every product - ideally one consistent format and responsible party across the range.

If you are a nail professional

Apply gel to the nail plate only; avoid the surrounding skin - this is the single most effective way to prevent methacrylate allergy.
Cure fully and follow lamp specifications; under-cured product means more uncured monomer in contact with skin.
Use gloves and ventilation, and keep SDS sheets accessible as your board requires.
In the EU, respect "professional use only" labelling - it exists for a reason.

08What this means for a professional nail tech

Regulations, CAS numbers and classifications are a lot to take in - so here is the part that actually matters at the desk. The real, everyday risk in gel work is not the lamp and not the finished nail. It is skin contact with uncured product. Allergic contact dermatitis from methacrylates such as HEMA and HPMA is the single most common problem in this category, and it builds up from repeated contact between uncured gel and skin - the client's, and yours.

What that means in practice:

Keep product off the skin. Apply to the nail plate, cap the free edge, and wipe any flooding of the sidewalls or cuticle. Most reactions trace back to uncured gel sitting on skin, not to the product itself.
Cure fully, every time. Use the correct lamp and timing for the system you're working with. Under-curing leaves reactive monomer behind - that is what sensitises skin.
Protect yourself; your exposure is cumulative. You handle these products all day. Wear nitrile gloves (not latex), keep airflow or extraction at the desk, and don't breathe filing dust.
The finished nail is inert. Once it's properly cured and on the plate, the enhancement is stable. The moment to respect is the wet product and the application - not the worn set.
Don't lose sleep over trace photoinitiator. In a properly cured product from a transparent supplier, a small amount of photoinitiator like TMO is not where your risk lives. Skin contact with uncured methacrylates is.
Buy on transparency. Choose products with a CAS-level SDS so you know what you're working with. Treat "HEMA-free" as a genuine plus, but still check whether HPMA replaced it, and confirm the photoinitiator.

In short: worry about skin contact and full cure, not about the lamp or a worn manicure. Good technique and honest products handle the rest - which is exactly why Nailspiracy publishes CAS-level Safety Data Sheets, so a tech can make an informed call instead of trusting a slogan.

09Where Nailspiracy stands

Nailspiracy formulates its gel range without HEMA (868-77-9) and without TPO (75980-60-8), the two ingredients now most heavily regulated in the EU. Every product is backed by a Safety Data Sheet that discloses composition at CAS-number level, so professionals and distributors can verify a claim rather than trust a slogan.

Nailspiracy's position is that a "free-from" claim is only worth making if it is precise, verifiable, and honest about trade-offs - including being transparent where a formula uses a HEMA alternative such as HPMA, or which photoinitiator replaced TPO. That standard of disclosure is the brand's baseline, not a marketing flourish.

For product-specific Safety Data Sheets and the full ingredient breakdown of any Nailspiracy gel, see the product page or contact the Nailspiracy team directly.

10Questions & answers

Is HEMA banned in the EU?

No. HEMA (CAS 868-77-9) is restricted, not banned, in the EU. Since 3 June 2021 it may only be used in professional nail products, which must carry the warnings "For professional use only" and "Can cause an allergic reaction" under Regulation (EU) 2020/1682.

Is HEMA banned in the United States?

No. HEMA is permitted in nail products in the US. There is no federal ban and no mandatory professional-use label, unlike in the EU.

Why was TPO banned in the EU?

TPO (CAS 75980-60-8) was classified as a reproductive toxicant (CMR category 1B). Under the EU Cosmetics Regulation, CMR 1B substances are prohibited in cosmetics, so TPO was added to Annex II and banned from 1 September 2025.

Is TPO still legal in the US?

Yes. As of June 2026 there is no US federal ban on TPO. This is a key EU-US divergence: a TPO-containing gel can be sold in the US but not in the EU.

How much TPO substitute (TMO) is safe in a gel?

The EU's Scientific Committee on Consumer Safety has assessed acylphosphine-oxide photoinitiators of the TMO type (CAS 270586-78-2) as posing no consumer health risk in nail products at use levels up to about 5%. TMO is not the banned TPO (75980-60-8) and has no harmonised EU classification, so suppliers may self-classify it differently. Always confirm the photoinitiator and its level on the product's SDS.

Does "HEMA-free" mean the product is hypoallergenic?

No. "HEMA-free" only means the product does not contain HEMA (868-77-9). Many HEMA-free gels use HPMA (27813-02-1), a related methacrylate that carries a similar skin-sensitisation risk. A HEMA-free product is not automatically allergen-free.

Is HPMA regulated?

HPMA (CAS 27813-02-1) is not specifically restricted in the EU or the US. It is, however, classified as a skin sensitiser (H317) and should be handled with the same skin-contact caution as HEMA.

What is the maximum allowed percentage of HEMA?

The EU restriction sets no numeric maximum; it limits HEMA to professional products with mandatory warnings. Industry formulations commonly go up to about 35%, but that is a practical norm, not a legal cap. The US sets no federal limit either.

What is the difference between MMA and HEMA?

They are different substances. MMA (methyl methacrylate, CAS 80-62-6) is the old acrylic monomer the FDA treats as poisonous and that 30+ US states ban. HEMA (868-77-9) is a different ester used in gels - legal in the US and restricted, not banned, in the EU. They are routinely confused but are not the same chemical.

What should a nail tech actually worry about?

Skin contact with uncured gel. Allergic contact dermatitis from methacrylates such as HEMA and HPMA is the most common real-world problem, and it comes from uncured product touching skin - not from the lamp or the finished nail. Keep product off the surrounding skin, cure fully, and protect yourself with gloves and ventilation.

Are Nailspiracy gels HEMA-free and TPO-free?

Yes. Nailspiracy formulates its gel range without HEMA (868-77-9) and without TPO (75980-60-8), and publishes CAS-level Safety Data Sheets so the claims can be verified directly.

11Glossary & sources

Annex II: List of substances prohibited in EU cosmetics (Regulation 1223/2009).
Annex III: List of substances restricted in EU cosmetics - allowed only under stated conditions.
CLP: EU Classification, Labelling and Packaging Regulation (1272/2008), which assigns hazard classes.
CMR 1B: Carcinogenic, Mutagenic or Reprotoxic, category 1B - a hazard class that triggers a cosmetics ban (this is what happened to TPO).
SCCS: Scientific Committee on Consumer Safety - the EU's independent scientific advisory panel.
Sensitiser: A substance that can cause an allergic reaction with repeated or improper skin contact.
Photoinitiator: The ingredient that starts curing when gel is exposed to UV/LED light (e.g. TPO, TMO, BAPO).
Self-classification: When a supplier assigns a hazard class itself because the substance has no EU-harmonised classification - which is why the same ingredient can be labelled differently by two factories.

Primary sources

Regulation (EC) No 1223/2009 - EU Cosmetics Regulation (Annexes II & III), via EUR-Lex.
Commission Regulation (EU) 2020/1682 - HEMA & Di-HEMA TMHDC restriction, via EUR-Lex.
Commission Regulation (EU) 2025/877 (Omnibus VII) - TPO prohibition effective 1 September 2025.
European Commission - TPO in nail products: Questions & Answers.
ECHA - TPO substance information & CLP Regulation (EC) No 1272/2008.
SCCS (Scientific Committee on Consumer Safety) - opinions underpinning the HEMA and photoinitiator assessments.
US FDA - Nail Care Products (Federal Food, Drug, and Cosmetic Act; MoCRA 2022).
California DTSC - Nail Products Containing MMA; US state cosmetology boards.

This article is educational reference content published by Nailspiracy and reflects the regulatory position as understood in June 2026. Regulations change; substance classifications are periodically updated. It is not legal or regulatory advice. For a specific product, formulation, or market-entry decision, consult the current official regulation and a qualified cosmetic safety assessor or regulatory advisor.