Codeofchina.com is in charge of this English translation. In case of any doubt about the English translation, the Chinese original shall be considered authoritative.
The occupational exposure limits given in Tables 1 to 3 in the text of this standard are compulsory, while the rest and those given in Table 4 are recommendatory.
This standard is developed in accordance with Law of the People's Republic of China on Prevention and Control of Occupational Diseases.
GBZ 2 Occupational exposure limits for hazardous agents in the workplace consists of the following two parts under the general title:
——Part 1: Chemical hazardous agents;
——Part 2: Physical agents.
This part is Part 1 of GBZ 2.
This part is developed in accordance with the rules given in GB/T 1.1-2009.
This part replaces GBZ 2.1-2007 Occupational exposure limits for hazardous agents in the workplace - Part1: Chemical hazardous agents. In addition to editorial changes, the following main technical changes have been made with respect to GBZ 2.1-2007.
——six normative references, i.e., GBZ/T 300, GBZ/T 192, GBZ/T 295, GBZ/T 224, GBZ/T 225 and GBZ/T 229.2, are added;
——nine concepts or definitions with regard to occupational exposure are added, terms in five normative references are deleted, and PE is introduced to replace the excursion limits;
——occupational exposure limits for 28 chemical hazardous agents that has been developed and revised in recent years are summarized and added.
——Chinese or English names and CAS Nos of eight chemical substances are adjusted;
——sensitization labels for 16 substances, skin labels for four substances, and carcinogenicity labels for 14 substances are added, and carcinogenicity labels for seven substances are adjusted;
——exposure limits for nitric oxide are incorporated into those for nitrogen dioxide;
——adverse health effects that are based during establishment of the exposure limits are clearly listed;
——biological limit values for occupational exposure (biological monitoring indexes and exposure limits) are added in Clause 4 “hygienic requirements”, and the released standard biological limit values for occupational exposure in the health industry and their determination methods are confirmed, and 28 biological monitoring indices and exposure limits are summarized and listed. 13 biological limit values for occupational exposure approved in recent years as well as quality requirements for biological material determination and biological monitoring are added;
——relevant requirements for monitoring and determination methods are further improved. For PC-TWA of total dust and respirable dust, it is specified that priority is given to the determination of TWA of the respirable dust;
——control principles and requirements for chemical hazardous agents in the workplace are added.
——Annex B is added, and information about chief drafting organizations and chief drafters of newly-added limits is given;
——Instructions for correct use of Annex A are further refined and improved. The control principles, key points and action levels of occupational exposure to hazardous agents, classification and control of occupational exposure levels, level-to-level management principles for hazardous operation of occupational diseases, etc., are added, and some contents in Annex A “Instructions for correct use” to the former standard have been revised into the text of the standard.
The previous editions of this part are as follows:
——GBZ 2-2002;
——GBZ 2.1-2007.
Occupational exposure limits for hazardous agents in the workplace - Part 1: Chemical hazardous agents
1 Scope
This part specifies the hygiene requirements, determination, evaluation and control principles for occupational exposure to chemical hazardous agents in the workplace.
This part is applicable to the hygienic design of industrial enterprises, as well as the management, control and occupational health supervision and inspection of occupational exposure to chemical hazardous agents in the workplace.
2 Normative references
The following referenced documents are indispensable for the application of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies.
GBZ 1 Hygienic standards for the design of industrial enterprises
GBZ 159 Specifications of air sampling for hazardous substances monitoring in the workplace
GBZ/T 160(all parts) Methods for determination of toxic substances in the air of workplaces
GBZ/T 192(all parts) Determination of dust in the air of workplaces
GBZ/T 224 Terms of occupational health
GBZ/T 225 Guideline for employer of prevention and control of occupational diseases
GBZ/T 229.2 Classification of occupational hazards at workplaces - Part 2: Occupational exposure to chemicals
GBZ/T 295 General principles of biological monitoring method in occupational population
GBZ/T 300(all parts) Methods for determination of toxic substances in the air of workplaces
3 Terms, definitions and abbreviations
For the purposes of this document, the terms and definitions established in GBZ/T 224 and the following ones apply.
3.1
chemical hazardous agents
the chemical hazardous agents mentioned in this part include chemical substances, dust and biological agents existing in or arising from the workplace
3.2
occupational exposure
the process that workers are exposed to occupational hazardous agents through respiratory tract, skin and mucosa in their occupational activities
3.3
adverse health effects
hazardous health efforts or toxic effects of the organism arising from the exposure to occupational hazardous agents. Only a certain level of exposure, i.e. excessive exposure, can cause health damage
3.4
critical adverse health effects
the adverse health effects that are used to determine the permissible exposure concentration of certain occupational hazardous agent, i.e. the adverse health effects that are based during the determination of the occupational exposure limits
3.5
occupational exposure limits; OELs
the permissible exposure level that the workers are repeatedly exposed to one or more occupational hazardous agents for a long time in their occupational activities, which will not cause adverse health effects on the vast majority of exposed persons. The occupational exposure limits of chemical hazardous agents can include three categories, i.e., permissible concentration-time weighted average, permissible concentration-short term exposure limit and maximum allowable concentration
Note: it is a revision of Definition 5.1 in GBZ/T 224-2010.
3.5.1
permissible concentration-time weighted average; PC-TWA
the average permissible exposure concentration for 40 h per work week (8 h per working day), specified with time as the weight
3.5.2
permissible concentration-short term exposure limit; PC-STEL
the weighted average concentration that allows the workers to be exposed for a short time (15 min), provided that the measured average exposure concentration for 40 h per work week (8 h per working day) meets the requirements of PC-TWA
Note: it is a revision of Definition 5.3 in GBZ/T 224-2010.
3.5.3
maximum allowable concentration; MAC
the concentration that any chemical hazardous agent shall not exceed within any working day, at any time and at any workplace
Note: it is a revision of Definition 5.2 in GBZT 224-2004.
3.6
peak exposures; PE
the maximum or peak concentration of a specific substance in the air determined in the shortest analyzable duration (no more than 15 min). For the chemical hazardous agents with PC-TWA but whose PC-STEL has not been established, peak exposures shall be used to control short-time contact. The maximum exposures of PC-TWA is allowed to be exceeded during any short time (15 min) within one working day
3.7
exposure level
the concentration or intensity of workers' actual exposure to occupational hazardous agents in the workplace in a specific period of time during their occupational activities, which is detected by a standard determination method
Note: it is a revision of Definition 2.22 in GBZ/T 224-2010.
3.8
ratio of occupational exposure level to OELs
the ratio of the actual exposure level of workers to certain occupational hazardous agents, to the corresponding occupational exposure limits of the agents
When workers are exposed to more than two kinds of chemical hazardous agents, the sum of the measured values of chemical hazardous agents and their corresponding occupational exposure limits is called the ratio of mixed exposure
3.9
action level
the workers’ actual exposure level to chemical hazardous agents at which the employers are required to take control measures or actions such as occupational exposure monitoring, occupational health monitoring, occupational health training, and occupational hazard notification, also called administration level or administration concentration
The action level of a chemical hazardous agent varies with the workplace environment and the hazardous agents, which is usually half of the allowable concentration of this agent
Note: it is a revision of Definition 2.23 in GBZ/T 224-2010.
3.10
biological monitoring
Systematical monitoring on the content (concentration) of chemical substances or their metabolites in biological materials such as blood and urine of workers, or the level of harmless biological effects caused by them, in order to evaluate the degree of workers' exposure to chemical hazardous agents and their possible health effects
Note: it is a revision of Definition 6.1.2 in GBZ/T 224-2010.
3.11
biological exposure limits; BELs
the maximum allowable value for chemical substances or their metabolites in workers’ biological materials, or for the biological effects caused by them, which is also a guiding value for evaluating biological monitoring results. As per five working days a week and eight working hours a day, when the biological monitoring value is within the recommended value range, the vast majority of workers will not be affected by adverse health effects. It is also known as biological exposure indices (BEIs) or biological limit values (BLVs)
Note: it is a revision of Definition 5.9 in GBZ/T 224-2010.
4 Hygiene requirements
4.1 occupational exposure limits for chemical hazardous agents in the air of workplace
Occupational exposure limits for chemical hazardous agents in the air of workplace are given in Table 1.
Foreword i
1 Scope
2 Normative references
3 Terms, definitions and abbreviations
4 Hygiene requirements
5 Monitoring and determination principles and requirements
6 Principles and requirements for occupational exposure control of chemical hazardous agents in workplaces
7 Instructions for proper use of this section
Annex A (Normative) Instructions for proper use of this section
Codeofchina.com is in charge of this English translation. In case of any doubt about the English translation, the Chinese original shall be considered authoritative.
The occupational exposure limits given in Tables 1 to 3 in the text of this standard are compulsory, while the rest and those given in Table 4 are recommendatory.
This standard is developed in accordance with Law of the People's Republic of China on Prevention and Control of Occupational Diseases.
GBZ 2 Occupational exposure limits for hazardous agents in the workplace consists of the following two parts under the general title:
——Part 1: Chemical hazardous agents;
——Part 2: Physical agents.
This part is Part 1 of GBZ 2.
This part is developed in accordance with the rules given in GB/T 1.1-2009.
This part replaces GBZ 2.1-2007 Occupational exposure limits for hazardous agents in the workplace - Part1: Chemical hazardous agents. In addition to editorial changes, the following main technical changes have been made with respect to GBZ 2.1-2007.
——six normative references, i.e., GBZ/T 300, GBZ/T 192, GBZ/T 295, GBZ/T 224, GBZ/T 225 and GBZ/T 229.2, are added;
——nine concepts or definitions with regard to occupational exposure are added, terms in five normative references are deleted, and PE is introduced to replace the excursion limits;
——occupational exposure limits for 28 chemical hazardous agents that has been developed and revised in recent years are summarized and added.
——Chinese or English names and CAS Nos of eight chemical substances are adjusted;
——sensitization labels for 16 substances, skin labels for four substances, and carcinogenicity labels for 14 substances are added, and carcinogenicity labels for seven substances are adjusted;
——exposure limits for nitric oxide are incorporated into those for nitrogen dioxide;
——adverse health effects that are based during establishment of the exposure limits are clearly listed;
——biological limit values for occupational exposure (biological monitoring indexes and exposure limits) are added in Clause 4 “hygienic requirements”, and the released standard biological limit values for occupational exposure in the health industry and their determination methods are confirmed, and 28 biological monitoring indices and exposure limits are summarized and listed. 13 biological limit values for occupational exposure approved in recent years as well as quality requirements for biological material determination and biological monitoring are added;
——relevant requirements for monitoring and determination methods are further improved. For PC-TWA of total dust and respirable dust, it is specified that priority is given to the determination of TWA of the respirable dust;
——control principles and requirements for chemical hazardous agents in the workplace are added.
——Annex B is added, and information about chief drafting organizations and chief drafters of newly-added limits is given;
——Instructions for correct use of Annex A are further refined and improved. The control principles, key points and action levels of occupational exposure to hazardous agents, classification and control of occupational exposure levels, level-to-level management principles for hazardous operation of occupational diseases, etc., are added, and some contents in Annex A “Instructions for correct use” to the former standard have been revised into the text of the standard.
The previous editions of this part are as follows:
——GBZ 2-2002;
——GBZ 2.1-2007.
Occupational exposure limits for hazardous agents in the workplace - Part 1: Chemical hazardous agents
1 Scope
This part specifies the hygiene requirements, determination, evaluation and control principles for occupational exposure to chemical hazardous agents in the workplace.
This part is applicable to the hygienic design of industrial enterprises, as well as the management, control and occupational health supervision and inspection of occupational exposure to chemical hazardous agents in the workplace.
2 Normative references
The following referenced documents are indispensable for the application of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies.
GBZ 1 Hygienic standards for the design of industrial enterprises
GBZ 159 Specifications of air sampling for hazardous substances monitoring in the workplace
GBZ/T 160(all parts) Methods for determination of toxic substances in the air of workplaces
GBZ/T 192(all parts) Determination of dust in the air of workplaces
GBZ/T 224 Terms of occupational health
GBZ/T 225 Guideline for employer of prevention and control of occupational diseases
GBZ/T 229.2 Classification of occupational hazards at workplaces - Part 2: Occupational exposure to chemicals
GBZ/T 295 General principles of biological monitoring method in occupational population
GBZ/T 300(all parts) Methods for determination of toxic substances in the air of workplaces
3 Terms, definitions and abbreviations
For the purposes of this document, the terms and definitions established in GBZ/T 224 and the following ones apply.
3.1
chemical hazardous agents
the chemical hazardous agents mentioned in this part include chemical substances, dust and biological agents existing in or arising from the workplace
3.2
occupational exposure
the process that workers are exposed to occupational hazardous agents through respiratory tract, skin and mucosa in their occupational activities
3.3
adverse health effects
hazardous health efforts or toxic effects of the organism arising from the exposure to occupational hazardous agents. Only a certain level of exposure, i.e. excessive exposure, can cause health damage
3.4
critical adverse health effects
the adverse health effects that are used to determine the permissible exposure concentration of certain occupational hazardous agent, i.e. the adverse health effects that are based during the determination of the occupational exposure limits
3.5
occupational exposure limits; OELs
the permissible exposure level that the workers are repeatedly exposed to one or more occupational hazardous agents for a long time in their occupational activities, which will not cause adverse health effects on the vast majority of exposed persons. The occupational exposure limits of chemical hazardous agents can include three categories, i.e., permissible concentration-time weighted average, permissible concentration-short term exposure limit and maximum allowable concentration
Note: it is a revision of Definition 5.1 in GBZ/T 224-2010.
3.5.1
permissible concentration-time weighted average; PC-TWA
the average permissible exposure concentration for 40 h per work week (8 h per working day), specified with time as the weight
3.5.2
permissible concentration-short term exposure limit; PC-STEL
the weighted average concentration that allows the workers to be exposed for a short time (15 min), provided that the measured average exposure concentration for 40 h per work week (8 h per working day) meets the requirements of PC-TWA
Note: it is a revision of Definition 5.3 in GBZ/T 224-2010.
3.5.3
maximum allowable concentration; MAC
the concentration that any chemical hazardous agent shall not exceed within any working day, at any time and at any workplace
Note: it is a revision of Definition 5.2 in GBZT 224-2004.
3.6
peak exposures; PE
the maximum or peak concentration of a specific substance in the air determined in the shortest analyzable duration (no more than 15 min). For the chemical hazardous agents with PC-TWA but whose PC-STEL has not been established, peak exposures shall be used to control short-time contact. The maximum exposures of PC-TWA is allowed to be exceeded during any short time (15 min) within one working day
3.7
exposure level
the concentration or intensity of workers' actual exposure to occupational hazardous agents in the workplace in a specific period of time during their occupational activities, which is detected by a standard determination method
Note: it is a revision of Definition 2.22 in GBZ/T 224-2010.
3.8
ratio of occupational exposure level to OELs
the ratio of the actual exposure level of workers to certain occupational hazardous agents, to the corresponding occupational exposure limits of the agents
When workers are exposed to more than two kinds of chemical hazardous agents, the sum of the measured values of chemical hazardous agents and their corresponding occupational exposure limits is called the ratio of mixed exposure
3.9
action level
the workers’ actual exposure level to chemical hazardous agents at which the employers are required to take control measures or actions such as occupational exposure monitoring, occupational health monitoring, occupational health training, and occupational hazard notification, also called administration level or administration concentration
The action level of a chemical hazardous agent varies with the workplace environment and the hazardous agents, which is usually half of the allowable concentration of this agent
Note: it is a revision of Definition 2.23 in GBZ/T 224-2010.
3.10
biological monitoring
Systematical monitoring on the content (concentration) of chemical substances or their metabolites in biological materials such as blood and urine of workers, or the level of harmless biological effects caused by them, in order to evaluate the degree of workers' exposure to chemical hazardous agents and their possible health effects
Note: it is a revision of Definition 6.1.2 in GBZ/T 224-2010.
3.11
biological exposure limits; BELs
the maximum allowable value for chemical substances or their metabolites in workers’ biological materials, or for the biological effects caused by them, which is also a guiding value for evaluating biological monitoring results. As per five working days a week and eight working hours a day, when the biological monitoring value is within the recommended value range, the vast majority of workers will not be affected by adverse health effects. It is also known as biological exposure indices (BEIs) or biological limit values (BLVs)
Note: it is a revision of Definition 5.9 in GBZ/T 224-2010.
4 Hygiene requirements
4.1 occupational exposure limits for chemical hazardous agents in the air of workplace
Occupational exposure limits for chemical hazardous agents in the air of workplace are given in Table 1.
Contents of GBZ 2.1-2019
Foreword i
1 Scope
2 Normative references
3 Terms, definitions and abbreviations
4 Hygiene requirements
5 Monitoring and determination principles and requirements
6 Principles and requirements for occupational exposure control of chemical hazardous agents in workplaces
7 Instructions for proper use of this section
Annex A (Normative) Instructions for proper use of this section
