On August 7, 2025, the National Institute of Chemical Safety (NICS) issued two separate administrative notices. One announced a new designation list of hazardous chemical substances reflecting the replacement of the former “toxic substance” concept with a new classification system of hazardous substances. The other introduced revisions to chemical GHS classification and labeling. Together, these notices reflect changes under the Act on the Registration and Evaluation of Chemicals (K-REACH) and the Chemicals Control Act (CCA) that were amended in 2024 and came into force on August 7, 2025. The following sections provide details on the resulting changes to Chemical Confirmation and Letter of Confirmation (LoC), the introduction of the OR system under the CCA, and the impacts on SDS requirements under K-OSHA.

The former single category of “Toxic Substances” has been abolished and replaced by three distinct categories: Human Acute Hazardous Substances, Human Chronic Hazardous Substances, and Environmental Hazardous Substances. Separate concentration thresholds now apply to each category. In addition, Substances with Unidentified Hazards have been newly defined for cases where hazard data are absent (acute, genetic, aquatic, biodegradability). This shall be confirmed through a new chemical notification under 1 ton/year, and substances notified after August 7th may be classified as Substances with Unidentified Hazards if the relevant hazard data are missing. Polymer substances are excluded from this scope.

A detailed comparison of the former and revised classification systems is provided in Attachment 1.

The CCA has been amended to introduce several important changes:

• Foreign manufacturers may now appoint an Only Representative (OR) on a product-by-product basis to handle “chemical confirmation” and “applications for substances subject to authorization” (note: no authorization substances have yet been announced).

• Existing LoC (Letter of Confirmation) formats for "Chemical Confirmation" remain valid until December 31, 2025. From August 7, 2025, the new format reflecting the revised classifications becomes available for use, and it will become mandatory from January 1, 2026. The new format is available in Attachment 3.

• Chemical confirmation must be resubmitted when a substance or mixture that was not previously designated as a toxic substance is newly designated as a Hazardous Substance (acute, chronic, or environmental), or when lowered concentration thresholds cause it to fall under the new designation. If a substance or mixture was already confirmed and submitted as a toxic substance or mixture, no resubmission is required. The deadline for resubmission is July 1, 2026.

• For mixtures containing benzene (No. 97-1-99) at 0.1%–1.0%, the compliance deadline is January 1, 2028, with an additional two years allowed under transitional provisions.

• For domestic operators, obligations have been segmented and, in many cases, eased. Requirements such as business licensing, handling and facility installation standards, facility inspections, and Chemical Accident Prevention Plans (CAPP) are now differentiated depending on the type of hazardous pathway (acute, chronic, environmental) and whether a facility directly handles such substances. For specific guidance, please contact us directly.

[Section 15. SDS Regulatory Information]

Under K-OSHA, SDS Section 15 must be updated to reflect the new hazardous substance classification system (Human Acute, Human Chronic, Environmental). This does not itself require resubmission, but importers and downstream users must provide updated information. A grace period until July 1, 2026 applies.

Substances with Unidentified Hazards must also be listed under K-REACH item in Section 15 with data gaps (acute, genetic, aquatic, biodegradability) and handling precautions*. If identified as unconfirmed, the composition shall be promptly reflected in the SDS to fulfil obligation of data provision under K-REACH, or alternatively satisfied by a legal form (Safety Use Information, Annex 25 or 26 under K-REACH) of data provision.

*Example of handling precaution: refer to the “Safe Use Guide for Substances with Unidentified Hazards” by NICS and ensure safe handling per Article 5 of the Act.

[Revised SDS Form of Section 15]

The Section 15 format has also been revised (grace period for adopting revised SDS template until June 30, 2026). Unconfirmed Hazard Substances should be recorded under the K-REACH section. Items previously listed under “Others” must now be shown separately as:

(a) Occupational Safety and Health Act

(b) Chemicals Control Act (CCA)

(c) Act on the Registration and Evaluation of Chemicals (K-REACH)

(d) Fire Safety Act for Hazardous Materials

(e) Waste Control Act

(f) Other domestic and foreign regulations

[Section 2. SDS Hazard Identification]

SDS resubmission is required if GHS hazard classification has changed. Where companies already apply equal or stricter classifications—e.g., by following international or EU schemes—resubmission is not needed. If stronger classifications are required under the amended notice, resubmission must be considered.

• Review substance portfolios against the new hazardous substance classification (acute, chronic, environmental) and confirm whether resubmission of LoC is required by July 1, 2026 for newly designated substances; note the special benzene deadline (January 1, 2028).

• Update SDSs: Section 2 if GHS classification has changed (resubmission required), and Section 15 to reflect the new format and classification system by the grace period deadlines (June 30, 2026 for format, July 1, 2026 for information update).

• Domestic operators should check revised requirements for licensing, inspections, and CAPP obligations.

For tailored guidance on how these amendments may impact your business, 

please contact Chemtopia for more detailed consulting:

☎ Inquiry: +82-(0)2-826-9100 (Main line), chemtopia@chemtopia.net