The Blog

The recent amendments to K-REACH, which came into force on August 7, 2025, introduced important changes including the new standard for “unknown hazard classification substance” and the subdivision of “toxic substances” into three specific categories. Companies importing such substances to Korean market must now provide the appropriate Korean SDS to their downstream users.

Background

Starting January 1, 2025, the minimum notification threshold for new substances increased to 1 ton, aiming to reduce regulatory burden on industry. However, a review showed that only 4% of previously notified new substances had submitted hazard data. With the threshold raised, it was expected that more substances would circulate without essential hazard information.

Recognizing that “no hazard data” does not mean “safe,” the concept of “unknown hazard classification substance” was introduced to help minimize potential risks to human health and the environment.

What is an “Unknown Hazard Classification Substance”?

Under Article 2, subparagraph 10-3 of K-REACH, it refers to any substance registered or notified under Article 10 for which hazard identification is difficult due to a lack of data, meeting any of the following criteria, excluding polymers:

• Acute oral toxicity has not been identified (or acute inhalation toxicity if the substance is gaseous or primarily inhaled due to its intended use)
• Neither reverse mutation nor chromosomal aberration has been identified using cultured mammalian cells
• No acute toxicity to fish, daphnia, or freshwater algae growth inhibition has been identified
• Biodegradability has not been identified

Subdivision of “Toxic Substances”

To transition to a risk-based, differentiated management system, the “toxic substance” has been subdivided into three:

• Acute hazardous substances to humans: Substances causing adverse health effects from short-term exposure
• Chronic hazardous substances to humans: Substances causing adverse effects from repeated or long-term exposure
• Ecologically hazardous substances: Substances harmful to the environment, such as aquatic life, from short-term exposure

Updating Korean SDS

Starting August 7, any company manufacturing or importing “unknown hazard classification substances” must presume these substances to be hazardous until proven otherwise and update their SDS to state that appropriate measures should be taken to prevent harm to human health or the environment.

For SDSs containing “toxic substances,” revisions to Section 15 (“Regulatory Information”) must be shared with downstream users by July 1, 2026, reflecting the new classifications. Importers and/or exporters should verify the classification of their substances accordingly.

REACHLaw Korea Support 

Understanding and complying with these updates can be challenging. At REACHLaw Korea, we provide comprehensive K-REACH support. If your company exports chemical substances to Korea, partnering with REACHLaw Korea ensures efficient navigation of regulatory requirements and smooth market access.

Please contact us at kreach@reachlaw.fi or sales@reachlaw.fi for support.