PFAS have become one of the most discussed chemical families of the decade – in drinking water, in frying pans and, less famously, in makeup. These "forever chemicals" give foundations their long wear and mascaras their waterproof hold. But the same property that makes them useful is exactly what makes regulators uneasy: they barely break down at all. Here is what PFAS actually are, why they end up in cosmetics, and how to find them in the ingredient list.

What PFAS are – and why "forever"

PFAS stands for per- and polyfluoroalkyl substances: a large family of thousands of synthetic chemicals built around carbon chains studded with fluorine atoms. The carbon–fluorine bond is one of the strongest in organic chemistry, which makes these molecules extraordinarily stable. That stability is the whole point industrially – and the whole problem environmentally. PFAS resist heat, water, grease and, crucially, degradation. Once released, many of them persist in soil, water and living organisms for a very long time.

Good to know: the nickname "forever chemicals" refers to the extremely stable carbon–fluorine bond, which means PFAS persist in the environment and in the body for a very long time. Skinimalist flags 94 substances as PFAS, based on the Swedish Chemicals Agency (KEMI) PFAS list mapped to the US EPA CompTox PFAS reference list.

Why they end up in your makeup bag

PFAS are not there by accident. In cosmetics they add slip and a smooth, silky feel, make products water- and sweat-resistant, and help long-wear formulas actually last. That profile explains where they most often turn up:

Watch out for: long-wear and waterproof makeup – it is the most common place to find PFAS. Scan the INCI list for names containing "fluoro" and for PTFE.

How to spot PFAS in the INCI list

Many – though not all – PFAS carry a telltale fragment in their INCI name: fluoro, perfluoro, polyperfluoro or the abbreviation PTFE. A few concrete examples:

INCI nameRole in productNote
PTFE (Polytetrafluoroethylene)Bulking / slip agentPFAS-family polymer; can carry trace PFOA from manufacturing
Perfluorooctanoic Acid (PFOA)No legitimate role todayForbidden in EU cosmetics (Annex II); REACH SVHC
Polyperfluoromethylisopropyl EtherSkin conditioningFluorinated polymer, part of the PFAS family
Names containing "Perfluoro", "Polyfluoro", "Nonafluoro"…Varies (film formers, emollients)E.g. Perfluorodecalin, C9-15 Fluoroalcohol Phosphate – the "fluoro" fragment is the cue

The name check is a useful shortcut, but it is not watertight in either direction: some fluorinated names belong to less-studied substances, and some PFAS hide behind names without an obvious "fluoro". This is where automated ingredient matching earns its keep.

Regulation is tightening

The clearest case is PFOA (Perfluorooctanoic acid). It is prohibited in EU cosmetics under Annex II of the Cosmetics Regulation and is a REACH Substance of Very High Concern, classified as toxic for reproduction and as PBT – persistent, bioaccumulative and toxic. Its harmonised classification also includes suspected carcinogenicity (H351) and reprotoxicity (H360).

Beyond PFOA, the direction of travel is broad: the EU is working toward a wide restriction of PFAS as an entire class under REACH, and several countries and US states have passed or proposed bans on intentionally added PFAS in cosmetics. None of this makes every product with a fluorinated ingredient illegal today – but the regulatory trend points one way.

An honest nuance

Not every fluorinated ingredient is equally studied or equally hazardous. PTFE, for instance, is officially "harmless" in ECHA self-classifications – it is flagged because it belongs to the PFAS polymer family and can carry trace PFOA as a manufacturing contaminant. Skinimalist models this precisely: PTFE is linked to PFOA as a possible contaminant, without pretending PTFE itself carries PFOA's hazard profile. For PFAS as a group, the main concerns are environmental persistence and bioaccumulation rather than acute harm to your skin.

If you want to reduce PFAS

Skinimalist recognises PFAS even under alternative names – its database covers 36,700+ ingredients and 91,200+ synonyms – and analyses the label entirely on your device, summing everything up in a score from 1 to 5.

Check your makeup for PFAS with Skinimalist. Scan the label or share a link – and see the score, the flagged forever chemicals and how well the product fits your skin.

Download on the App Store

Sources: Swedish Chemicals Agency (KEMI) PFAS list; US EPA CompTox PFAS reference list (PFASOECD); EU Cosmetics Regulation (EC) No 1223/2009, Annex II (PFOA prohibition); ECHA REACH Candidate List (SVHC) and CLP harmonised classifications (H351, H360); ongoing EU REACH restriction proposal for PFAS as a class. This guide is decision support, not medical advice.