What changed
Under South Korea's Act on Registration and Evaluation of Chemical Substances, commonly called K-REACH, existing substances register in phased deadlines by annual manufacture or import tonnage band:
| Tonnage band | Registration deadline |
|---|
| ≥ 1,000 t/y (and CMR substances ≥ 1 t/y) | 31 December 2021 (passed) |
| 100 – 1,000 t/y | 31 December 2024 (passed) |
| 10 – 100 t/y | 31 December 2027 |
| 1 – 10 t/y | 31 December 2030 |
The next major deadline still open is 31 December 2027, for existing substances manufactured or imported in Korea at 10 t/y or more and less than 100 t/y.
Legal status
This is an upcoming mandatory registration deadline, not a voluntary data request. Companies manufacturing or importing relevant existing substances in South Korea need a registration strategy completed before the applicable deadline. Pre-registration or late pre-registration may allow manufacture/import during the grace period, but it is not the final registration itself.
Why this needs attention
The 10–100 t/y band can include many specialty chemicals, additives, intermediates, raw materials and formulation components — often lower visibility than high-volume substances, but still business-critical.
The risk is treating 31 December 2027 as distant. In practice, K-REACH registration can require Korean importer coordination, Only Representative decisions, tonnage confirmation, joint-registration participation, data-ownership review, test-data gap analysis, Korean-language dossier preparation, hazard and risk assessment, and cost sharing with a lead registrant.
For global exporters, the key question is not only whether the company sells finished products to Korea — it's whether any Korean legal entity manufactures or imports the substance at or above the relevant annual tonnage band.
Compliance impact
This update can affect Korean market access, import release, substance master data, supplier and customer declarations, chemical inventory checks, regulatory budget planning, SDS Section 15 Korea information, product launch timelines, Korean importer responsibilities, Only Representative agreements, and joint-registration cost sharing.
K-REACH registration is separate from GHS/SDS classification — but hazard data generated or collected for registration may later affect Korean SDS and label classification if it changes the hazard assessment.
Recommended actions
Portfolio and tonnage screening
- Identify all substances manufactured or imported into South Korea, and confirm whether each is an existing chemical substance under K-REACH.
- Determine the annual Korean tonnage band per substance and legal entity, and confirm whether any 2021 or 2024 deadline substance remains unresolved.
- Prioritise substances in the 10–100 t/y band for the 31 December 2027 deadline.
Pre-registration and registration status
- Verify whether the substance was pre-registered or late pre-registered — do not treat pre-registration as final registration.
- Confirm whether the Korean importer or an Only Representative owns the registration responsibility, and check whether the company has joined the correct joint-registration group.
- Identify the lead registrant and expected cost-sharing model, and track status as: not scoped, pre-registered, late pre-registered, joint registration in progress, dossier submitted, registered, or blocked.
Data-gap and dossier preparation
- Collect available physicochemical, toxicological and ecotoxicological data, and review data ownership and right-to-use letters.
- Identify missing studies or waiving possibilities, and confirm whether Korean-specific test or format requirements apply.
- Prepare hazard and risk assessment data, and align SDS hazard information with validated registration data where relevant.
Supply-chain responsibility
- Clarify with Korean customers whether they will register as importers, and decide whether the non-Korean supplier will appoint an Only Representative.
- Avoid duplicate registration costs where several Korean importers handle the same substance, and include K-REACH registration clauses in supply contracts.
- Confirm who receives Korean authority communications, and maintain evidence for customer assurance statements.
Business continuity
- Identify substances where Korean sales depend on timely registration, and estimate registration and data-purchase cost.
- Rank products by commercial risk — critical, strategic, replaceable, or discontinue candidate — and set internal decision deadlines well before 31 December 2027.
- Block new Korean launches if the K-REACH registration strategy is unclear, and prepare substitution or reformulation options for substances unlikely to be registered in time.
Reviewed by CHEMREG Regulatory Team · Last reviewed 16 Sept 2026