Walk down any skincare aisle and the exfoliating acids sit side by side: a 2% BHA liquid, an 8% AHA toner, a PHA serum marketed for sensitive skin. The packaging treats them as one family. Regulators do not.
We queried our database of 21,796 cosmetic ingredients across 10 markets and pulled every exfoliating acid with a regulatory entry. Salicylic acid — the BHA — is restricted in 9 of the 10 markets we track. Glycolic acid, the most common AHA, carries explicit restrictions in 3. The PHAs barely register at all, with Canada as the main exception. Same shelf, same purpose, very different rulebooks.
The three acid families
A quick orientation for anyone outside formulation work. AHAs — glycolic, lactic, mandelic, malic, tartaric — are water-soluble acids that loosen the bonds between dead skin cells at the surface. BHA means salicylic acid in practice: oil-soluble, able to work inside pores, which is why it dominates acne products. PHAs — gluconolactone, lactobionic acid — are chemically AHAs with larger molecules, marketed as the gentler option because they penetrate more slowly.
The chemistry is related. The regulatory treatment is not.
Salicylic acid: restricted in 9 of 10 markets
In our database, salicylic acid carries regulatory entries in the EU, Korea, Japan, China, Taiwan, ASEAN, Brazil, Argentina, and Canada. The US is the only market in our set without a general concentration restriction on it as a cosmetic ingredient.
The EU entry is the most detailed, and several other markets mirror its structure. Under the EU Cosmetics Regulation, salicylic acid used for purposes other than preservation is capped at 3% in rinse-off hair products and 2% in other products — with a carve-out list (body lotion, eye shadow, mascara, eyeliner, lipstick, roll-on deodorant) where only preservative use at 0.5% is allowed. As a preservative, the cap is 0.5% across the board. And products containing it must warn that they are not for children under three, except shampoos.
Korea's entry follows the same three numbers — 0.5%, 2%, and 3% depending on function and product type — as do ASEAN, Brazil, and Argentina. The alignment is not a coincidence; these markets largely inherited the EU's annex structure for this ingredient. Japan, China, and Taiwan carry their own conditions, and Taiwan additionally requires on-pack cautionary statements. Canada folds salicylic acid into its broader acid rules, discussed below.
| Market | Non-preservative use | As preservative | Children under 3 |
|---|---|---|---|
| EU | 3% rinse-off hair / 2% other | 0.5% | Prohibited (except shampoo) |
| Korea | 0.5% / 2% / 3% by use | 0.5% | — |
| ASEAN / Brazil / Argentina | 3% / 2% (EU-aligned) | 0.5% | Prohibited (except shampoo) |
| Japan / China / Taiwan | Own conditions | — | Taiwan: on-pack warning |
| Canada | Under acid category (see below) | — | — |
| US | No general cap | — | — |
One more entry from the same family is worth flagging: acetylsalicylic acid — aspirin — is listed as prohibited in cosmetics in our Canadian data. It is not an exfoliating-acid ingredient in practice, but its presence on a prohibition list while salicylic acid is merely capped shows how narrowly these rules are drawn: one acetyl group changes the answer.
The AHAs: three markets, one detailed rulebook
Glycolic acid, lactic acid, and mandelic acid carry explicit restriction entries in three of our markets: Canada, Taiwan, and ASEAN. Everywhere else — the EU included — they are listed with general limits or conditions rather than the hard product-by-product caps salicylic acid gets. The EU has SCCS safety opinions on AHAs and general safe-use conditions, but no annex entry with the granularity of the salicylic acid one.
Canada is the market that regulates AHAs most explicitly, through its Cosmetic Ingredient Hotlist. The Hotlist treats alpha-hydroxy acids as a category — and, since its 2024 update, explicitly includes polyhydroxy acids and bionic acids in that category. Consumer products are capped by concentration with a minimum pH of 3.5; professional-use products run higher, up to 30%, with mandatory cautionary statements above 3%. Anything stronger or more acidic crosses out of cosmetics into drug territory.
| Use category (Canada) | Max concentration | pH floor | Note |
|---|---|---|---|
| Consumer | 10% (up to 18% in some 2024 categories) | ≥ 3.5 | Warning required above 3% |
| Professional | 30% | 3.0–3.5 | Above these → classified as a drug |
| PHA / bionic acids | Same as AHA | Same | Explicitly folded in (2024) |
Taiwan's entries for lactic and mandelic acid focus on labeling: mandatory cautionary statements on packaging, with specific rules for hair-dye and perm products. ASEAN distinguishes general use from professional use, echoing the Canadian split.
The PHAs: regulated almost nowhere, except where they are AHAs
Gluconolactone and lactobionic acid — the two PHAs a consumer is most likely to meet — carry almost no dedicated restrictions in our data. Their main regulatory home is Canada, and the mechanism is telling: Health Canada did not write a PHA rule. It clarified that PHAs fall under the existing alpha-hydroxy acid entry, inheriting the same concentration and pH conditions.
That clarification cuts against the marketing. PHAs are sold as the gentle alternative to AHAs, and their slower skin penetration supports the positioning. But to the one regulator that has looked closely, they are the same category of substance with the same rules. "Gentler" is a formulation claim, not a regulatory one.
Why the BHA gets nine rulebooks and the AHAs get three
The gap has a chemical explanation. Salicylic acid is a salicylate — the same family as aspirin — and systemic salicylate exposure is a known concern for young children. That is why the EU rule singles out children under three, why the SCCS revisited children's exposure as recently as 2025, and why the ingredient earned a detailed, product-by-product annex entry. The EU has also classified salicylic acid as a Category 2 reproductive toxicant, which keeps it under active review.
The AHAs raise a different and milder concern: they increase the skin's sensitivity to UV. That risk is managed with concentration caps, pH floors, and sunburn-alert labeling — the Canadian model — rather than prohibitions in specific product types. Different hazard, different regulatory machinery.
What this means in practice
For a formulator or regulatory team, the acid family determines the compliance work. A salicylic acid product needs a market-by-market concentration check against nine different entries, plus child-labeling in the EU-aligned markets. An AHA product needs a concentration-and-pH check mainly for Canada, Taiwan, and ASEAN, plus sun-sensitivity labeling. A PHA product is mostly unregulated territory — until it ships to Canada, where it becomes an AHA.
For a consumer reading labels, the practical point is simpler: the percentage on the front of an acid product is not a strength score that regulators ignore. In most major markets, that number is the direct subject of a rule — and for salicylic acid, one of the most tightly specified numbers in cosmetics.
What the data does not show
Our database records restriction entries, not every regulatory instrument. The EU's AHA position lives partly in SCCS opinions and general safety obligations rather than annex entries, so a count of explicit restrictions understates how much scrutiny AHAs receive there. The US also regulates through post-market enforcement and industry guidance rather than concentration lists, so its near-absence from this comparison reflects method, not indifference — a pattern we covered in our 10-country restriction count.
Concentration limits also change. The SCCS issued a new opinion on salicylic acid and children's exposure in 2025, and Canada rewrote its AHA entry as recently as 2024. The numbers here reflect our database at the time of writing.
Methodology and Sources
Ingredient and regulatory data: K-Beauty Cosmetic Ingredients database, 21,796 ingredients across 10 markets — the EU, Korea, Japan, China, Taiwan, ASEAN, Brazil, Argentina, Canada, and the US. We searched for exfoliating-acid ingredients by INCI name (glycolic, lactic, salicylic, mandelic, malic, tartaric, gluconolactone, lactobionic, and related entries) and reviewed each match, excluding non-exfoliating relatives such as thioglycolic acid (a perm ingredient) and polymer forms.
External verification: the EU salicylic acid limits (3% rinse-off hair, 2% other products, 0.5% as preservative, prohibition in products for children under three except shampoos) were checked against Regulation (EC) 1223/2009 Annex III/V summaries and the 2025 SCCS opinion on children's exposure. The Canadian AHA conditions (consumer concentration cap with pH 3.5 minimum, professional use up to 30%, PHA inclusion) were checked against Health Canada's Cosmetic Ingredient Hotlist and its 2024 amendments.
For related ingredient families, see our retinoid analysis and the paraben comparison. For the underlying data, see K-Beauty Cosmetic Ingredients on RapidAPI.
Important Notice: This article is for informational purposes only. It is not legal, regulatory, or medical advice. Cosmetic regulations change and vary by market, and concentration limits in particular are under active review in several jurisdictions. Anyone making formulation or compliance decisions should consult the current text of the relevant regulation and a qualified professional. For full terms, see our Disclaimer.
Decoded Korea publishes data-driven analysis of Korean cosmetic ingredients, chemical regulations, and safety data.
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