Acetone oxime, a chemical used to help synthesize fragrance compounds, was banned from cosmetics in Europe on May 1, 2026. Most people who have it in a perfume, lotion, or nail product sitting on their bathroom shelf have no idea it’s there. That’s partly because of how cosmetics labeling works, and partly because regulators in different countries draw the line in very different places.
The European Union added 15 prohibited substances and two restricted substances to its updated list of chemical ingredients recently classified as carcinogenic, mutagenic, or toxic for reproduction – a category scientists abbreviate as CMR. CMR is regulatory shorthand for chemicals that may cause cancer, alter DNA, or damage the reproductive system. Under EU rules, a CMR classification triggers an automatic cosmetics ban. There are no lobbying delays, no multi-year review windows, no industry grace periods to reformulate at leisure. Once the classification is official, the clock starts immediately.
Products containing these substances had to be withdrawn from the EU market by May 1, 2026, with the bans fully applicable from that date, resulting in certain substances being either prohibited outright or subject to restricted use. Manufacturers didn’t get the luxury of selling through existing stock. For retailers with shelves full of non-compliant products, that meant physical removal, not just a promise to reformulate next quarter. In the US, these same 15 chemicals remain legal in personal care products.
What CMR Chemicals Are – and Why Cosmetics Chemicals Banned in Europe Matter
CMR is scientific shorthand for chemicals that may raise cancer risk, alter DNA, or interfere with fertility and fetal development. Substances classified as CMRs under EU chemical law are automatically banned under Article 15 of the Cosmetics Regulation, unless a specific exemption is granted.
Among the newly prohibited substances, acetone oxime – a compound used in synthesizing scent ingredients – was added to the banned list as a presumed carcinogen. The list also includes 2,3-epoxypropyl neodecanoate, used as a diluent to reduce viscosity in formulations, and 1,4-dichloro-2-nitrobenzene, used in the production of pigments and UV absorbents. Another banned substance, trimethyl borate, is capable of causing serious eye irritation, skin irritation, and respiratory tract irritation, according to its safety data, with potential reproductive harm.
Many of these substances weren’t originally developed as cosmetic ingredients. They’re industrial chemicals – used in agriculture, chemical manufacturing, or dye production – that could theoretically migrate into personal care formulations if left off the prohibited list. The EU added them preemptively, before they had a chance to show up in foundation or shampoo. All ingredients classified as CMR 1A or 1B are automatically prohibited, while category 2 substances may be prohibited or restricted. Using these ingredients after their prohibition is illegal under Article 15 of the EU cosmetics regulation and can lead to mandatory product recalls, sales bans, fines, and criminal liability in certain cases.
The Gel Nail Polish Ban That Came First
The May 2026 ban on 15 CMR substances followed an earlier wave of EU enforcement. As of September 1, 2025, trimethylbenzoyl diphenylphosphine oxide – commonly known as TPO – was prohibited in cosmetic products across the EU, after animal studies suggested it could be toxic to human reproduction.
TPO is a photoinitiator, meaning it’s the chemical in gel nail polish that responds to UV light and causes the polish to harden. In gel nail polish, it helps the polish set under ultraviolet light. Commission Delegated Regulation (EU) 2024/197 classified TPO as a CMR category 1B reproductive toxicant, with this classification applying from September 1, 2025, which triggered its mandatory inclusion in the list of prohibited cosmetic substances.
The animal studies underpinning the decision were conducted in rats. TPO’s reproductive toxicity classification is based on studies of rodents ingesting the compound. At high doses, it caused testicular shrinkage in male rats. David Andrews, Ph.D., acting chief science officer at the Environmental Working Group, noted that the EU banned TPO both at home and professionally due to reproductive toxicity concerns identified in animal studies, with the toxicity studies showing testicular abnormalities and reduced fertility.
The animal studies found that when animals ingested high levels of TPO, they experienced fertility and reproductive health issues – a kind of exposure that is completely different from what happens when humans apply gel nail polish. Kelly Dobos, a cosmetic chemist and adjunct professor at the University of Cincinnati, noted that ingestion is not a relevant route of exposure for someone wearing nail polish. “That’s not really how we’re exposed to it in a nail gel,” said Dobos. “Your systemic exposure is very low, because it’s also reacted away when you’re exposing it to that light in the nail lamp.”
But the EU’s regulatory framework doesn’t require proof of harm at real-world exposure levels. A hazard classification is enough to trigger a ban. The US has not taken regulatory action against TPO in gel nail polishes, largely because the US follows a risk-based regulatory approach that considers both the hazard and the likelihood of exposure.
Nail salons across the EU’s 27 member states, as well as countries like Norway and Switzerland that follow EU rules, had to stop selling TPO-based gels and safely dispose of existing stock. In the United States, TPO remains legal and unrestricted in its use and sale.
The 15 Banned Substances Include:
| Chemical | Primary Use |
|---|---|
| Methylenediisocyanate (MDI) derivatives | Key ingredients in polyurethane foams, insulation, coatings, and industrial adhesives. |
| Silver (Nano) | Nanoscale silver used for its antimicrobial properties in coatings, textiles, and medical applications. |
| Trimethyl Phosphate | Industrial solvent and intermediate used in the manufacture of specialty chemicals. |
| 1,4-Benzenediamine, N,N’-mixed Ph and tolyl derivatives | Chemical additives used to improve the durability of rubber products and specialty polymers. |
| Acetone Oxime | Used as a stabilizer in paints and industrial water treatment systems; classified as a suspected carcinogen. |
| 2,3-Epoxypropyl Isopropyl Ether | Reactive chemical used in epoxy formulations and advanced polymer production. |
| Perboric Acid and its salts | Oxidizing and bleaching compounds historically used in detergents and industrial cleaning products. |
| Formic Acid, reaction products with aniline | Intermediate used in the production of dyes, coatings, and synthetic resins. |
| Trimethyl Borate | Chemical reagent used in industrial synthesis; prolonged exposure has been associated with reproductive and organ toxicity. |
| N,N’-Methylenediacrylamide | Cross-linking agent commonly used to produce laboratory gels and biomedical research materials. |
| 2,3-Epoxypropyl Neodecanoate | Industrial intermediate used in epoxy resins, protective coatings, and adhesives. |
| Benzyl(diethylamino)diphenylphosphonium reaction mass | Catalyst used to accelerate chemical reactions during polymer manufacturing. |
| 1,4-Dichloro-2-nitrobenzene | Industrial intermediate used in the manufacture of specialty chemicals and other chemical products. |
| Sodium 3-(allyloxy)-2-hydroxypropanesulphonate | Specialty monomer used to produce water-soluble polymers for industrial applications. |
| Silver (Massive) | Bulk silver used in electronics, manufacturing, and other industrial processes. |
The Gap Between EU Action and US Regulation – and How cosmetics chemicals banned in Europe reflect a systemic divide
Alexa Friedman, a senior scientist at the Environmental Working Group, told the Vice that “unlike the EU, the US does not have a similar mechanism that automatically bans chemicals classified as carcinogenic, mutagenic, or toxic for reproduction.”
In the US, the absence of an automatic ban doesn’t just mean a slower process. It means there’s no process at all, unless regulators actively choose to act. Most cosmetic ingredients never cross an FDA desk before they reach consumers – manufacturers self-certify safety under loose federal guidelines, and the agency’s main enforcement tool is the after-the-fact recall. Friedman has described the US cosmetic industry as “heavily under-regulated” compared to other countries.
Andrews has noted that “the EU takes a proactive approach of restricting and banning chemicals that are identified as causing health harms, mostly in animals, while the US FDA approach is more wait and see if anything bad happens.” Some toxicologists argue that hazard-based bans, triggered by animal studies at doses that don’t reflect real-world use, can overstate risk for consumers. The EU’s precautionary principle accepts that trade-off. The US doesn’t default to it.
The same regulatory gap that separates how Europe and the US treat cosmetic chemicals also shapes how PFAS in common consumer products enter wastewater systems and the broader environment.
Hazard vs Risk: Why EU/US Regulations Differ
The European Union and the United States take different approaches to regulating cosmetic ingredients. The EU generally follows a hazard-based model, meaning an ingredient can be restricted or banned if it has the potential to cause harm under any foreseeable conditions, even if exposure in cosmetics is low. By contrast, U.S. regulators primarily use a risk-based approach, evaluating both a substance’s hazardous properties and the amount consumers are actually exposed to during normal use. As a result, some ingredients prohibited in EU cosmetics may remain permitted in the U.S. when regulators determine they can be used safely under specified conditions.
What the US Has Done Instead
The US hasn’t been entirely static. The Modernization of Cosmetics Regulation Act of 2022 (MoCRA) is the most significant expansion of FDA authority to regulate cosmetics since the Federal Food, Drug, and Cosmetic Act was passed in 1938. MoCRA establishes new requirements for the cosmetics sector, including mandatory facility registration, product listing, safety substantiation, and adverse event reporting. These are genuine structural improvements. But they don’t come with a CMR-style automatic ban mechanism.
On PFAS – the class of synthetic chemicals known as “forever chemicals” because they don’t break down in the environment or the body – state governments have moved faster than Washington. California was the first US state to ban PFAS in cosmetics, effective January 1, 2025, under the PFAS-Free Cosmetics Act. Colorado enacted a similar prohibition effective January 1, 2025, and Washington State’s law also took effect January 1, 2025, prohibiting the manufacture, sale, or distribution of cosmetics with intentionally added PFAS.
By late 2025, nearly 20 states had enacted or proposed legislation restricting PFAS, formaldehyde, lead, and other substances in cosmetics. Beyond PFAS, certain states are advancing broader chemical restriction frameworks. Washington State’s Toxic-Free Cosmetics Act, for example, targets a wider group of substances considered harmful, including formaldehyde-releasing ingredients, specific heavy metals, and other chemicals of concern.
California also enforces the Toxic-Free Cosmetics Act, which bans 24 specific toxic chemicals, with a second wave adding 26 more substances in 2027. That’s meaningful progress, but it creates a different problem: a fragmented patchwork of state-by-state rules that cosmetics companies have to track and navigate individually.
At the federal level, the FDA released a congressionally mandated report on PFAS in cosmetics on December 29, 2025. While the report reviewed available scientific evidence on potential safety concerns, the FDA’s evaluation did not reach definitive safety determinations and underscored significant uncertainty due to gaps in existing data on PFAS exposure through cosmetics. The FDA found that for 19 of the 25 most frequently used PFAS it assessed – 76% of them – toxicological data were incomplete or unavailable, preventing a definitive safety conclusion. The agency stopped short of recommending a nationwide ban. Multiple bills, including the Toxic-Free Beauty Act of 2025, remain pending in Congress.
The FDA has also proposed banning formaldehyde and formaldehyde-releasing compounds in hair straightening products, according to regulatory timeline data from late 2025. Formaldehyde is a known human carcinogen that has been linked to cancer risk among salon workers who use straightening treatments regularly – a concern that state-level regulators and health advocates flagged years before the federal proposal emerged.
What This Means for You
If you live in California, Colorado, Washington, or one of the other states with active PFAS bans, your cosmetics are already subject to some of the stricter rules in the world. Brands that sell nationally often reformulate to comply with the most restrictive state standard, which means products available everywhere start changing even without a federal mandate.
If you want to check what’s in your products right now, the Environmental Working Group’s Skin Deep database lets you search by product or ingredient and see how they’re rated for safety. It won’t match the EU’s CMR list exactly, but it flags many of the same categories of concern: reproductive toxins, carcinogens, and developmental hazards. For gel nail polish specifically, look for TPO-free labeling on the packaging – most major EU-reformulated brands have already made this change for their European lines, and some are rolling it out globally. Products that were fully compliant two years ago may no longer pass muster in the EU or California, which tells you something about how quickly the science and the regulations are both moving.
The regulatory philosophy dividing Europe and the US – whether to act on early hazard signals or wait for direct evidence of harm in humans – is a genuine scientific and policy debate. The EU’s automatic CMR filter creates a practical information advantage for consumers on that side of the Atlantic. They know, at minimum, that anything on shelves has cleared an automatic screening mechanism. In the US, that filter doesn’t exist yet.
Disclaimer: The information provided here is for educational and informational purposes only and is not a substitute for professional psychological, psychiatric, or mental health advice, diagnosis, or treatment. Always seek the guidance of a licensed mental health professional, therapist, psychologist, or psychiatrist with any questions or concerns about your emotional well-being or mental health conditions. Never ignore professional advice or delay seeking support because of something you have read here.
A.I. Disclaimer: This article was created with AI assistance and edited by a human for accuracy and clarity.
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