Thailand's Food and Drug Administration has opened consultation on draft amendments that would add 10 prohibited substances to the country's cosmetic ingredient annex and align existing concentration limits with the ASEAN Cosmetic Directive (ACD), according to regulatory consultancy CIRS Group.

That is the core data point CIRS has flagged: 10 new prohibited substances, plus a broader realignment of Thailand's positive and negative lists with the regional ACD schedule.

What does the proposal actually cover?

Thailand regulates cosmetics under the Cosmetics Act B.E. 2558, with ingredient annexes administered by the Thai FDA. The current proposal does not reform the parent statute — it updates the annexes that sit beneath it.

The draft does two things at once:

• It adds 10 substances to the prohibited list. Once in force, these substances cannot be used in any cosmetic product placed on the Thai market, regardless of concentration or product category.
• It realigns existing concentration limits with the values set by the ASEAN Cosmetic Directive, the harmonized schedule adopted by all 10 ASEAN member states.

The practical effect is convergence: Thailand-specific numerical limits that historically sat alongside the ACD schedule will, if the draft is finalized, be replaced by the regional values.

Why does ACD alignment matter for cross-border brands?

ASEAN operates a mutual recognition arrangement (MRA) for cosmetic notifications. A product notified in one member state can, in principle, be marketed across the bloc on the basis of a single notification dossier, provided the formulation complies with the ACD.

The implication for multi-market brands is that a Thailand-specific prohibited-substance addition, once enacted, tends to migrate into ASEAN-wide product portfolios. A substance newly prohibited under the Thai annex will, in practice, disappear from regional SKU lines within the standard reformulation cycle that contract manufacturers and brand owners run for any annex change.

For the operational teams directly affected, the checklist is straightforward:

• Audit current SKUs against the 10 new prohibited substances
• Cross-check existing concentration limits against ACD-aligned values
• Update product information files (PIFs) and on-pack labeling where use conditions change
• Prepare written submissions during the consultation window where reformulation costs warrant a comment

What's not in the public summary

The summary CIRS Group has flagged does not name the 10 proposed prohibited substances by INCI designation, does not identify which concentration limits are being realigned, and does not state the consultation deadline or the expected entry-into-force date. The consultancy's notification indicates only that the Thai FDA has published the draft for stakeholder comment.

Formulators, regulatory affairs teams and procurement leads should pull the Thai FDA's full consultation document before reprioritizing reformulation pipelines. The 10 INCI names, once published, will determine whether any current formulations need to be pulled, re-engineered or quarantined.

Where does this fit in the regional pattern?

Thailand's move mirrors a broader ASEAN convergence exercise. Indonesia, Vietnam, the Philippines and Malaysia have each completed, or are in the process of completing, similar alignment rounds for their positive and negative annexes. The harmonization work matters more than the headline figure of 10 substances: it removes the historical patchwork of national numerical limits and replaces it with a single regional schedule that brands can build a multi-market dossier against.

What to watch next

The next data points are the consultation outcome document, the entry-into-force date once the draft clears comment, and the transition period Thailand grants for products already on the market. Watch also for parallel ACD annex revisions at the next ASEAN Cosmetic Committee meeting, since Thai proposals have historically moved in step with the regional direction of travel rather than against it.