Is salicylic acid allowed in leave-on cosmetics in the EU, the UK, Canada, South Korea and Japan? Give the maximum concentration, product types and required warnings in each market, citing each market's official list.

Yes, salicylic acid is allowed in leave-on cosmetics in all five markets, but the limits differ a lot. Non-preservative use goes up to 2% in the EU, the UK and Canada. Korea's list allows 0.5% (as a preservative only), and Japan allows 0.20 g per 100 g (0.2%) in any cosmetic. The EU, UK and Korean lists require an under-3s warning; the Canadian and Japanese list entries contain no warning text.

Approach: I checked the official ingredient lists in each market: the current consolidated EU Cosmetics Regulation (EC) No 1223/2009 and its amending acts, the GB-retained text of that Regulation, Health Canada's Cosmetic Ingredient Hotlist, MFDS's Standards for Safety of Cosmetics (Annexes 1 and 2), and MHLW's Standards for Cosmetics (Notification No. 331). For the Korean label warning and Canada's drug/cosmetic boundary I used official government web pages, read only as search snippets.

Market	Leave-on maximum	Product types	Required warning
EU	2.0% in leave-on products other than those in the 0.5% group; 0.5% in body lotion, eye shadow, mascara, eyeliner, lipstick, roll-on deodorant; 0.5% as a preservative	Annex III entry 98 (non-preservative use) and Annex V entry 3 (preservative)	"Not to be used for children under 3 years of age"
UK (GB)	Same as the EU: 2.0% / 0.5% / 0.5% preservative	Annex III ref. 98 and Annex V ref. 3	"Not to be used for children under 3 years of age"
Canada	2%	No product-type split in the Hotlist	None in the Hotlist entry
South Korea	0.5% (as a preservative, calculated as the acid)	Higher limits only for body-cleansing (2%) and rinse-off hair products (3%)	Under-3s warning (Enforcement Rule Annex 3)
Japan	0.20 g/100 g; salicylates 1.0 g/100 g in total	Table 3 (preservatives), single limit for all cosmetics	None in the Standards entry

EU. There are two entries. Annex III entry 98 covers uses other than as a preservative, and that purpose must be apparent from how the product is presented. The limits are 3.0% in rinse-off hair products, 2.0% in other products, and 0.5% in body lotion, eye shadow, mascara, eyeliner, lipstick and roll-on deodorant. These levels include any preservative use ^[1]. Both entries ban use in products for children under 3, in oral products, and in applications that may expose the user's lungs by inhalation. Annex V entry 3 allows salicylic acid and its salts as a preservative at 0.5% (as the acid) ^[2].

• Why it is still allowed: salicylic acid is classified as a category 2 CMR substance. Regulation (EU) 2019/1966 granted the Article 15(1) exception ^[3]. It also extended the under-3s ban from "except shampoos" to all products for that age group ^[4].
• The 0.5% group: Regulation (EU) 2021/850 added the 0.5% allowance for body lotion, eye shadow, mascara, eyeliner, lipstick and roll-on deodorant ^[5].
• Possible future change: the 2019 act notes that endocrine-disruption testing was under way and might need to be taken into account later ^[6].

UK (GB). The retained Annex III ref. 98 has the same three product groups, limits, conditions and under-3s warning ^[7]. Annex V ref. 3 matches the EU preservative entry at 0.5% (as the acid) ^[8].

Canada. The Hotlist (2025 edition) lists salicylic acid (CAS 69-72-7) as restricted, with a maximum of 2%. It gives no product-type conditions or warnings ^[9]. The French edition has the same entry ^[10]. Health Canada's pages say salicylic acid can be used in both drugs and cosmetics, and that its classification depends on how the product is represented. It also appears in the Natural Health Products acne therapy monograph, so an anti-acne claim takes a product out of the cosmetic route (search snippet).

South Korea. Annex 2 of the MFDS Standards lists salicylic acid and its salts as a preservative at 0.5% (as the acid). It must not be used in infant products or in products labelled specifically for children aged 13 or under, except shampoos ^[11].

• Other entry (wash-off only): a second Annex 2 entry allows 2% in body-cleansing products and 3% in rinse-off hair products, with the same children's ban. The captured text of this entry is partly garbled, but it appears to allow these uses only as the active ingredient of a functional cosmetic ^[12]. I found no leave-on allowance above 0.5%.
• Label warning: under Annex 3 of the Cosmetics Act Enforcement Rule, products containing salicylic acid or its salts must carry a "do not use on children aged 3 or under" caution. Shampoos and other wash-off products are excluded (from a law.go.kr search snippet).

Japan. Salicylic acid is in Table 3 (preservatives), subsection 1, with a maximum of 0.20 per 100 g ^[13]. Salicylates have a separate limit of 1.0 in total ^[14]. The figure is in g/100 g, and subsection 1 is the "upper limit for all cosmetics" column, so it applies equally to leave-on and rinse-off products (search snippet of the MHLW notification). The Standards entry carries no warning wording, and I found no separate official label warning for cosmetics.

I can look up the CLP Annex VI classification, or Japan's quasi-drug (医薬部外品) route for acne products, next if that would help.

Sources:

• MFDS: Cosmetics Act Enforcement Rule, Annex 3 (law.go.kr)
• MHLW: Standards for Cosmetics, Notification No. 331
• Health Canada: Salicylic acid
• Health Canada NHPID: Acne Therapy monograph