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[Comparative study on occupational exposure limits of chemical hazardous factors in China and NIOSH limits in the United States].

Researchers

X H Qian, J Dang, X Liu, L Han, B L Zhu

Abstract

Objective: To compare and analyze the occupational exposure limits (OELs) specified in China's "Occupational Exposure Limits for Hazardous Agents in the Workplace-Part 1: Chemical Hazardous Agents" (GBZ 2.1-2019) with the recommended exposure limits (RELs) issued by the National Institute for Occupational Safety and Health (NIOSH) in the United States, aiming to identify chemical hazardous factors requiring optimization of OELs. Methods: In March 2025, using the Chemical Abstracts Service registration number (CAS RN) as the core matching identifier, OELs from GBZ 2.1-2019 and NIOSH RELs in the United States were entered into Excel 2019 to construct a database. The OELs were matched one-to-one according to their classification types. Descriptive statistical methods were employed to analyze the ratio of exposure limits, and content comparisons were conducted to evaluate differences in classification types, legal status, and labeling applications. Results: The types and connotations of limits in China and the United States were basically the same. Among the 272 shared limits, 38.2% (104 items) were consistent, 23.9% (65 items) were basically consistent, and 37.9% (103 items) showed significant differences. There were 51 China standards that were significantly stricter than NIOSH standards in the United States, and 17 China standards that were significantly more lenient than NIOSH standards in the United States. Differences existed between China and the United States limits in terms of legal status and the application of certain labels. Conclusion: Domestic interim standards should be formulated as needed for internationally recognized but unestablished OELs, and OELs that are excessively strict, overly broad or inconsistent with type values should be adjusted. It is recommended to shorten or establish a dynamic OELs update mechanism. 目的： 通过比较分析我国GBZ 2.1-2019《工作场所有害因素职业接触限值　第1部分：化学有害因素》中职业接触限值（occupational exposure limits，OELs）与美国国家职业安全与健康研究所（National Institute for Occupational Safety and Health，NIOSH）发布的推荐接触限值（recommended exposure limits，RELs），筛选需优化调整的化学有害因素OELs。 方法： 于2025年3月，以化学文摘社登记号（Chemical Abstracts Service registration number，CAS RN）为核心匹配标识，将GBZ 2.1-2019中的OELs与美国NIOSH RELs录入Excel 2019构建数据库，按限值类型一一匹配，对限值比值进行描述性分析，并通过内容比对，对限值类型、法律地位和标识应用等进行分析。 结果： 中国和美国限值类型及内涵基本相同，共有的272项限值中有38.2%（104项）一致，23.9%（65项）基本一致，37.9%（103项）显著差异。51项中国标准明显严于美国NIOSH标准，17项中国标准明显宽于美国NIOSH标准；中国和美国限值在法律地位、部分标识应用等方面存在不同。 结论： 应按需制定国际上已识别未制定OELs的国内临时标准，调整过严、过宽和类型数值不相符的OELs，建议缩短或建立动态OELs更新机制。.