China Updates Workplace Hazardous Chemical OELs Standards

China National Health Commission released new OELs (occupational exposure limits) for Chemical Hazardous Agents in the Workplace, which will take effect and replace GBZ 2.1-2007 on 1st April 2020. In the new edition, Peak Exposure will replace Excursion Limit to describe the short-time exposure limit for chemical hazardous agents without a specific PC-STEL value. The Critical Adverse Health Effects, which determine the concentration limits of a hazardous agent, are described in the table together with the limit values of the agent now. Content relevant to the determination of exposure level when exposed to more than two kinds of hazardous agents, biological monitoring and the exposure level grading system and corresponding measures, etc. are added as well.

On 27^th August, the National Health Commission of People’s Republic of China released GBZ 2.1-2019 ^[1], namely, the 2019 version of Occupational Exposure Limits for Hazardous Agents in the Workplace (Part 1: Chemical Hazardous Agents). The new version will take effect and replace GBZ 2.1-2007 (English version available on Chemlinked ^[2]) on 1^st April, 2020. In the new version, besides the update of OELs and substance information, the description method of short-time exposure limit for hazardous agents without PC-STEL is changed. The content of adverse health effects, ratio of occupational exposure level to OELs, biological exposure limits and the grading of exposure level and corresponding measures, etc. are added as well.

Introduction

GBZ 2 (Occupational Exposure Limits for Hazardous Agents in the Workplace) was revised into 2 parts: 2.1 Chemical Hazardous Agents and 2.2 Physical Agents. In GBZ 2.1-2019, the hygiene requirements, testing evaluation and control principles of occupational exposure to chemical hazardous agents in the workplace are stipulated. The standard is applicable to the industrial enterprise hygiene design, management and control of occupational exposure to chemical hazardous agents in the workplace and occupational health supervision and inspection, etc.

Main Modification

Peak Exposures Replaces the Excursion Limits

In GBZ 2.1-2007, Excursion Limits are used to describe the concentration limit for chemical hazardous agents without a clear PC-SETL value. Excursion Limits are multiples of the agents’ PC-TWA value and cannot be exceeded during any short-time contact (15 mins). While, Peak Exposure, which is used in the 2019 version, is the maximum or the peak concentration of a special agent during the shortest analyzable period (within 15 mins). To protect the workers from an acute poisoning of the chemical hazardous agents, Peak Exposure can do better than Excursion Limits.

Specifies the Basis for Determining the Limits: Critical Health Adverse Effects

In the table which specifies the limit values of the chemical hazardous agents, now the critical adverse health effects of each agent have been added as a remark. According to its definition, the Critical Adverse Health Effects is used to determine the permissible contact concentration of a hazardous agents, that is to say, the occupational exposure limits are determined by these effects. For different agents, the Critical Adverse Health Effects are different as well. For example, the critical effects of chlorine is upper respiratory tract and eye irritation, while for chlorobenzene, the critical effect is liver damage. Specification of the critical health adverse effects can not only help enterprises inspect their own workplace, but also warn the employees away from these hazardous agents when adverse health effects happen on them.

Other Updates

Here are some other new content in GBZ 2.1-2019:

The Ratio of Occupational Exposure Level to OELs and Ratio of Mixed Exposure are described to evaluate the exposure level when workers are exposed to more than two chemical harmful factors.
A grading system for exposure level is newly established, and the recommended control measures for each level are given together.
The biological monitoring measures are initiated to better evaluate the influence of the chemical hazardous agents to workers’ health.
The regulation that for dust with both total and respiratory values, only the respiration value needs to be determined is cleared.
Content about occupational exposure control principles and requirements for chemical hazardous agents in workplace are added, including priority principle; control points; control requirements; control measures; exposure level grading system and corresponding measures, etc.

Conclusion

It has been 12 years from the previous version of GBZ 2.1 to the new one, so plenty of updates have been made in the new GBZ 2.1-2019. On one hand, with the development of research and technology, more scientific description methods and inspection measures have been taken. On the other hand, to better protect the workers from adverse effects of the chemical hazardous agents, the new edition has made effort to be more considerate and careful. After the revised standard enters into effect next year, the health of employees will be better protected than ever before.