根据 REACH 附件 IX 和 X 提交测试方案的注册人，在满足特定条件的情况下，可以免除 28 天研究。但是，如果由于已提交 90 天重复剂量毒性试验方案而导致 28 天重复剂量毒性试验没有结果，则无法得出 DNEL。在这种情况下，可以推荐哪些临时风险管理措施 (RMM)？

根据 REACH 附件 IX 和 X 提交测试方案的注册人，在满足特定条件的情况下，可以免除 28 天研究。但是，如果由于已提交 90 天重复剂量毒性试验方案而导致 28 天重复剂量毒性试验没有结果，则无法得出 DNEL。在这种情况下，可以推荐哪些临时风险管理措施 (RMM)？

Registrants who submit a proposal for testing in accordance with Annexes IX and X of REACH may waive 28-day studies if certain conditions are fulfilled. However, if there are no results for a 28-day repeated dose toxicity study because a testing proposal for a 90-day repeated dose toxicity test is made, it is not possible to derive a DNEL. Which interim risk management measures (RMM) could be recommended in this situation?

临时 RMM 应纳入化学品安全报告 (CSR)，并传达给物质的使用者（根据 REACH 第 31 条或 32 条，以暴露场景 (ES) 或其他形式）。此类 RMM 需要描述在缺乏足够毒理学信息的情况下以及等待拟议的长期危害测试结果期间如何以适当的方式处理物质。如果没有衍生无效应水平 (DNEL)，则注册人应参考已确定的用途和预期暴露情况进行定性风险表征，并证明这些措施足以控制风险（基于现有知识）。有关适用于此类情况的典型 RMM 的更多信息，请参阅《信息要求和化学品安全评估指南》E 部分表 E.3-1。如果没有或没有足够的物质危害信息，注册人应通过最大限度地减少物质的排放和/或暴露来证明风险控制。在此过程中，注册人可以结合使用围堵措施和/或局部排气通风 (LEV) 和/或个人防护设备 (PPE) 作为临时 RMM，以保护工人免受暴露。由于这些措施的临时性，与上述指南表 E.3-1 中的建议相比，PPE 可能发挥更为突出的作用。注册人收到测试方案的结果并能够得出 DNEL（或确定如果测试中未发现“阈值”效应，则需要最小化排放/暴露）后，可能需要更新其 CSR 和 ES。这尤其适用于临时措施基于 PPE 而非围堵措施或其他工程措施的情况。

Interim RMM are to be included into the Chemical Safety Report (CSR) and to be communicated to the users of the substance (either under Article 31 or 32 of REACH, in form of Exposure Scenario (ES) or otherwise). Such RMMs need to describe how to handle a substance in an appropriate way in the absence of sufficient toxicological information and while waiting for the results of proposed testing for long-term hazards. If no Derived No-Effect Level (DNEL) is available, the registrant is expected to carry out a qualitative risk characterisation referring to the identified uses and the expected exposure and justifying that the measures are sufficient to control the risks (based on the available knowledge). For more information on the typical RMM applicable in such cases, see the Guidance on information requirements and chemical safety assessment, Part E, Table E.3-1.Where no or not enough hazard information on the substance is available, the registrant should demonstrate control of risks by minimizing the emission and/or exposure to the substance. In doing so, he can use a combination of containment and/or Local Exhaust Ventilation (LEV) and/or Personal Protective Equipment (PPE) as interim RMM to protect workers from exposure. Due to the interim nature of the measures, PPE may play a more prominent role compared to what is suggested in table E.3-1 of the abovementioned Guidance. The registrant may need to update his CSR and ES once he receives the result of the test proposal and is able to derive a DNEL (or identify that minimisation of emission/exposure is required if "no threshold" effects had been identified in the testing). This applies in particular if the interim measures had been based on PPE instead of containment or other engineering measures.