Thailand’s Food and Drug Administration (Thai FDA) has opened a further public consultation on the regulatory impact analysis supporting proposed amendments to the country’s cosmetic ingredient requirements. The review covers 11 entries involving prohibited ingredients, seven entries for substances permitted subject to restrictions, one preservative entry and two sunscreen ingredients.

The proposals were previously consulted on from 9 June to 8 July 2026. This additional review represents another stage in the rulemaking process and does not mean that the proposed ingredient changes have entered into force.

Regulatory Background

The amendments are being developed under Thailand’s Cosmetic Act B.E. 2558 (2015). Article 22(3) authorizes the Cosmetic Committee to recommend subordinate measures governing substances used in cosmetic products.

The proposals are intended to align Thailand’s national ingredient requirements with updates to the ASEAN Cosmetic Directive. Thai FDA maintains separate regulatory lists for prohibited substances, restricted substances, preservatives, colourants and UV filters.

Proposed Prohibited Ingredients

The 11 prohibited-list changes comprise revisions and proposed additions. The June draft materials identify new entries covering certain petroleum, coal-tar and natural-gas derivatives containing at least 0.1% 1,3-butadiene, together with Quaternium-15, trimethylolpropane triacrylate, phenacetin and benzophenone.

The proposals also cover miconazole and miconazole nitrate, bifonazole, clotrimazole, thiabendazole and tioconazole. If adopted, these substances could no longer be used as cosmetic ingredients under the conditions established in the final notification.

The petroleum-related entry is particularly broad because it refers to 57 CAS-numbered derivatives. Companies should therefore screen raw-material specifications and supplier documentation rather than searching only for one representative CAS number.

Restricted Substances and Preservatives

The supplied regulatory-impact update identifies seven entries for substances permitted under specified conditions. Publicly available June draft information confirms proposed changes affecting salicylic acid, zinc pyrithione, verbena absolute, Acid Yellow 3 and butylated hydroxytoluene.

The proposal would reduce the permitted concentration of zinc pyrithione to 1% in rinse-off products and 0.1% in leave-on products. Acid Yellow 3 would be permitted in non-oxidative hair-dye products at a maximum concentration of 0.5%, while BHT would be subject to different limits depending on the product category. The ASEAN Cosmetic Directive identifies maximum BHT concentrations of 0.001% in mouthwash, 0.1% in toothpaste and 1% in other leave-on and rinse-off products. 

Quaternium-15 would be removed from the list of permitted preservatives and transferred to the prohibited-substance list. The associated preservative warning requirement would consequently become unnecessary once the prohibition takes effect.

Sunscreen Ingredients

The two sunscreen entries concern homosalate and benzophenone-3, also known as oxybenzone. Homosalate would be limited to non-aerosol facial sunscreen products at a maximum concentration of 7.34%.

Benzophenone-3 would be limited to sunscreen products for the face, hands and lips at a maximum concentration of 6%. These changes would narrow the currently permitted applications and may require reformulation of products intended for other body areas or delivery formats. 

Implementation Timeline

The first consultation ran from 9 June to 8 July 2026. The closing date for the latest regulatory-impact consultation is not specified in the supplied source and should be confirmed through the Thai legal-consultation portal.

The June drafts proposed that the amendments would take effect following publication in the Royal Thai Government Gazette, with a 180-day transition period for affected products. This arrangement remains subject to the final gazetted texts.

Industry Impact

Cosmetic notification holders, manufacturers, importers and ingredient suppliers should screen marketed and developing formulations against the proposed changes. Companies should prioritize products containing homosalate, benzophenone-3, salicylic acid, zinc pyrithione, Quaternium-15, BHT and Acid Yellow 3.

Supplier declarations should also be reviewed for petroleum-derived ingredients that may contain 1,3-butadiene. Where an affected ingredient is identified, companies should assess reformulation, alternative ingredients, updated safety assessments, Product Information File changes and revised notification information.

Products should not be withdrawn or reformulated solely on the assumption that the drafts are already mandatory. Companies should follow the consultation and prepare for the final Gazette publication and transition period.