How to Prepare Hazard and Exposure Assessments for Taiwan’s Standard Registration for Existing Chemicals
Introduction
On June 18, 2025, the Taiwan Region’s Chemical Substance Management Agency conducted an online briefing. The registration of hazard and exposure assessment information for the first batch of 106 designated existing chemical substances requiring standard registration has officially commenced.
As per the announcement, most enterprises had fulfilled the data requirements outlined in Appendix 3 of the Registration Measures (Items 1 to 7) by the end of 2024. Subsequently, enterprises must either voluntarily or within the deadlines designated by the Central Competent Authority, register the data items specified in Appendix 4 (i.e., Item 8: Hazard Assessment and Item 9: Exposure Assessment).
During the briefing, four substances were designated, requiring the completion of hazard and exposure assessment information registration by the end of 2026. REACH24H reminds relevant enterprises to pay close attention.
What Are the Designated Substances?
The Chemical Substance Management Agency has selected four substances, based on a comprehensive evaluation of their hazard characteristics, exposure scenarios, and data completeness, for which hazard and exposure assessment data must be registered by the designated deadlines.
| Substance name | CAS No. |
| Diantimony trioxide | 1309-64-4 |
| Sulfuric acid | 7664-93-9 |
| Toluene | 108-88-3 |
| Zinc oxide | 1314-13-2 |
No deadlines have been specified at this stage for the remaining 102 substances; however, enterprises may opt for voluntary registration.
Hazard and Exposure Assessment Requirements
For hazard assessments, the authorities will provide assessment report templates for the four designated substances. Registrants may submit the official reports directly without additional preparation. If registrants choose not to adopt the official version, they must prepare their own assessment reports.
For exposure assessments, registrants must independently prepare assessment data, as actual exposure scenarios vary among them. At this stage, registrants may first submit basic information on exposure scenarios. If the authorities later determine that a substance or case poses high-risk concerns, they may request supplementary detailed exposure data or conduct on-site inspections. Registrants involved solely in storage, sales, or other activities without unsealing or mixing operations may declare no exposure scenarios and are exempt from submitting exposure assessments.
Operational Requirements and Deadlines
| Registration Category | Whether there is any exposure situation in the factory area of the registrant | Should be completed before 2025/12/31 | Should be completed before 2026/12/31 | |
| Individual registration or
LR
|
Yes | Download the hazard assessment report sample and confirm whether you agree with the sample report (if you do not agree with the official report, you need to fill out another survey form) | Agree | Review and update items 1 and 2, and submit exposure scenario information |
| Disagree | Review and update items 1-7, submit hazard assessment reports and exposure scenario information | |||
| No | Agree | Review and update items 1 and 2, and submit a description of the non-exposure scenario | ||
| Disagree | Review and update items 1-7, submit hazard assessment report and non-exposure statement | |||
| Members who register together | Yes |
— |
Submit exposure scenario information | |
| No | Submit a non-exposure statement | |||
Voluntary Registration
In addition to the four designated substances that must submit hazard and exposure assessments by the deadlines, other substances currently have no specified deadlines. However, enterprises may still voluntarily complete the registration.
Note that voluntary registration necessitates the complete submission of hazard and exposure assessment data. For the exposure assessment, in addition to exposure scenario information, it must also include exposure quantity estimation and risk characterization description. In cases involving joint registrants, they must notify their joint registrants to submit the exposure assessment.
| Registration Category | Submitted by | Submission method |
| Designated Deadline Registration | The original case submitter and the person who supplemented the information are the same | Online Supplementary Information |
| The original case was submitted by the agent, and the registrant now needs to provide additional information | Official documents
|
|
| Voluntary Registration |
/ |
Official documents
|
Important Reminder from REACH24H
REACH24H reminds relevant enterprises: the official hazard assessment report templates are anticipated to be published in July. Enterprises should promptly download and review them on the registration platform.
The authorities will send a system notification containing a questionnaire. If enterprises disagree with the templates, they must respond to the questionnaire by December 31, 2025, and submit the hazard assessment data by December 31, 2026. If enterprises agree with the templates, no further action is required.
If you have any questions in this regard, please feel free to contact us at customer@reach24h.com.
