Thailand's 8th Edition Hazardous Substance List: FDA Restricts Hydrogen Peroxide and Chlorine-Releasing Substances to Domestic and Public Health Uses

Thailand revised its national Hazardous Substance List to its 8th Edition, B.E. 2568 (2025), through a Ministry of Industry notification published in the Royal Gazette on July 7, 2025 and effective the following day, July 8, 2025. It is the first update to the list since the 7th Edition took effect in December 2022, and it amends five separate schedules across three regulators at once: Lists 1.1 and 1.2, which sit under the Department of Agriculture; Lists 4.1 and 4.2, which sit under Thai FDA; and List 5.1, which sits under the Department of Industrial Works. For importers and manufacturers whose products fall under Thai FDA's hazardous substance regime specifically, two changes in Lists 4.1 and 4.2 matter immediately: hydrogen peroxide and chlorine and chlorine-releasing substances were both reclassified under Lists 4.1 and 4.2 to a narrower, restricted-use category rather than being removed from Thai FDA's oversight.

What actually changed in Lists 4.1 and 4.2

List 4.1 previously named hydrogen peroxide as an individually controlled hazardous substance under Thai FDA's jurisdiction. The 8th Edition does not remove it from that list; it reclassifies it into Category 3, restricting permitted use to domestic and public health applications such as bleaching, disinfecting, and general cleaning. List 4.2 previously controlled "chlorine and chlorine-releasing substances" as a defined group, covering the broad family of compounds that release free or available chlorine in use, the active chemistry behind most household bleach products and many pool and water-treatment sanitizers. The 8th Edition reclassifies that group the same way, into Category 3, restricted to domestic and public health uses, which for chlorine specifically includes applications like unclogging pipes alongside disinfecting and cleaning. Both changes read as narrow, technical amendments on paper, but they touch two of the most common active ingredients in the disinfectant, sanitizing, and cleaning product categories that Thai FDA has historically regulated, so the practical footprint is larger than the two-line notification suggests. Neither substance is deregulated: both remain controlled hazardous substances, just under a narrower set of permitted uses than before.

Why this is the kind of change that gets missed

A company that already holds a Thai FDA hazardous substance registration for a hydrogen-peroxide-based disinfectant, or for a chlorine-releasing sanitizing product, built its compliance file around the assumption that its product's classification is fixed once approved. It is not. The Hazardous Substance List is periodically revised, and a revision can remove a substance from the specific list a company's product was classified under just as easily as it can add one. This is exactly the kind of list churn DeeMED flags on its hazardous substance classification page: the classification a product received at initial registration is a snapshot, not a permanent status, and a company that never revisits it after approval can end up out of step with the current list without ever having done anything wrong.

The 8th Edition is a useful illustration of how a list revision can tighten a product's compliance obligations rather than loosen them. A business that already built its registration, labeling, and import documentation around Thai FDA's Type 3 requirements for a hydrogen-peroxide or chlorine-releasing product needs to confirm its declared end use still fits within the new Category 3 restriction, domestic and public health uses only, rather than assuming its existing registration and declared use automatically carry over unchanged. Reading this revision as deregulation, or assuming a product no longer needs its Thai FDA registration at all, is the mistake this notification specifically invites.

Where a reclassified product actually lands

Staying on Thai FDA's List 4.1 or 4.2 under the new Category 3 restriction means a hydrogen-peroxide or chlorine-releasing product remains regulated in Thailand, just against a narrower band of permitted declared uses than before. The Hazardous Substance Act's six-agency structure, covered at the framework level on DeeMED's FDA jurisdiction and product scope page, splits authority by declared end use, not by chemical identity, and the 8th Edition's other amendments to List 5.1 (Department of Industrial Works) confirm that the same revision cycle touched the industrial-use list in parallel. A hydrogen peroxide product formulated for industrial bleaching, sterilization, or manufacturing use outside the new domestic/public-health restriction may need to be reclassified under the Department of Industrial Works instead of Thai FDA, depending on its specific formulation and declared use. A household disinfectant or general cleaning product built around the same active ingredient can generally continue under its existing Thai FDA Type 3 registration, but only if its declared use fits within the new Category 3 restriction; a product whose declared use falls outside domestic and public health applications needs to be reassessed against where it actually lands under the current list.

The practical starting point for any company affected is the same regardless of which direction the change cuts: re-run the classification exercise for the specific product, in its specific formulation, against the current 8th Edition list, rather than assuming last year's classification still holds.

The 30-day and 180-day compliance windows

Thailand built transition mechanics into this revision rather than leaving affected businesses to sort out the switch on their own timeline. Businesses newly brought into scope, or newly taken out of scope, under the amended lists had 30 days from the July 8, 2025 effective date, roughly through August 6, 2025, to file the relevant permit applications or otherwise adjust their registration status to match the new classification. Some of the transitional directives tied to specific provisions carried a longer 180-day compliance window instead, giving businesses affected by those particular changes more runway to complete the adjustment. A company that missed the initial 30-day window because it did not realize the 8th Edition applied to its product is not automatically out of options, but it is now operating with a registration status that no longer matches the current list, which is a gap worth closing before an import shipment or a routine inspection surfaces it.

Who should re-check their classification now

Any company importing or manufacturing hydrogen-peroxide-based products, disinfectants, cleaning agents, and some cosmetic or personal care formulations among them, should confirm whether its product's Thai FDA registration status changed under the 8th Edition. The same applies to chlorine or chlorine-releasing disinfectant and sanitizing products, including household bleach-type products and pool chemicals. A product whose declared use fits within the new Category 3 restriction, domestic and public health uses, generally stays under Thai FDA's Type 3 hazardous substance registration, but a product formulated or marketed for a use outside that restriction, industrial applications especially, could now be controlled under a different list entirely, or by a different agency such as the Department of Industrial Works. The only way to know which of those outcomes applies to a specific product is to check the current list directly rather than extrapolate from the general "hydrogen peroxide and chlorine were reclassified" summary, since that summary is true at the level of the notification but does not resolve any individual product's actual status.

What this means going into the next revision cycle

The gap between the 7th Edition (December 2022) and the 8th Edition (July 2025) ran roughly two and a half years, long enough that a company can reasonably forget the list is a living document rather than a fixed reference table. Building a periodic recheck into a compliance calendar, even a simple annual review of a product portfolio against the current published list, costs far less than discovering during an import inspection or a renewal cycle that a product's classification quietly changed one or two revisions ago. DeeMED handles exactly this kind of hazardous substance classification and registration work for companies bringing disinfectant, sanitizing, and cleaning products into the Thai market, confirming current classification against the live list before a shipment or a registration renewal runs into a mismatch. Companies with hydrogen peroxide or chlorine-releasing products already on the Thai market, or planning to enter it, should treat the 8th Edition as the trigger to re-verify their classification now, rather than waiting for the 9th Edition to raise the same question again.