1 Preparation before preparation of the detection plan
The content of the detection plan includes: selection of sampling points, sampling objects, sampling methods and sampling timing, etc. In order to properly develop a testing protocol, an on-site investigation of the workplace must be conducted prior to sampling. Pre-sampling can be performed if necessary.
The investigation content mainly includes:
The types, quantities, purity, impurities and physical and chemical properties of raw materials and auxiliary materials used in the work process, products, by-products and intermediate products produced wait. The work process includes raw material input methods, production processes, heating temperature and time, production methods and the integrity of production equipment, etc. The working conditions of workers, including the number of workers, time spent at the workplace, working methods, degree, frequency and duration of exposure to harmful substances, etc. The generation and diffusion rules, existence status, estimated concentration, etc. of harmful substances in the air at the workplace. The health and environmental conditions of the workplace, health protection facilities and their use, personal protective facilities and their use, etc.
2 Basic requirements for the selection of testing points
The requirements for occupational exposure limits of hazardous substances in the workplace should be met.
Should meet the requirements of occupational health evaluation.
Should meet the requirements of workplace environmental conditions.
A control test should be conducted while sampling, that is, bring the air collector to the sampling point. Except for collecting air samples without connecting the air sampler, operate the same sample as a blank control for the sample. Therefore, the number of samples in the detection plan should be added to the number of blank controls.
3 Requirements for sampling in evaluation and testing work
Evaluation and testing is suitable for pre-evaluation of occupational disease hazard factors in construction projects, evaluation of the control effect of occupational disease hazard factors in construction projects, and evaluation of the current status of occupational disease hazard factors.
When evaluating the occupational exposure limit as the time-weighted average allowable concentration, a representative sampling point should be selected and sampling should be conducted continuously for 3 working days, which should include the working day with the highest concentration of harmful substances in the air. .
When evaluating the occupational exposure limit as the allowable concentration for short-term exposure or the maximum allowable concentration, representative sampling points should be selected and sampling should be conducted during the period when the concentration of harmful substances in the air is the highest within a working day. , continuous sampling for 3 working days.
4 Fixed-point sampling
4.1 Principles for selecting fixed-point sampling points
Choose representative workplaces, which should include workplaces with the highest concentration of harmful substances in the air, labor The workplace where the person has the longest contact time.
The sampling point should be as close to the worker as possible without affecting the worker's work; the air collector should be as close as possible to the worker's breathing zone while working.
When evaluating the protective effect of protective equipment or measures in the workplace, sampling points should be selected based on the conditions of the equipment, and samples should be taken from the respiratory belts of workers at the workplace when they are working.
The sampling point should be located in the downwind direction of the work site and away from the exhaust port and places where eddy currents may be generated.
4.2 Determination of the number of fixed sampling points
According to the production process of the product, at least one sampling point should be set up in any workplace where hazardous substances are released or present.
When there are multiple production equipment of the same type in a representative workplace, one sampling point is set for 1 to 3 units; 2 sampling points are set for 4 to 10 units; and at least 3 sampling points are set for 10 or more units. sampling points.
In a representative workplace, there are more than two production equipment of different types. When the same hazardous substance is emitted, the sampling point should be set up near the equipment with a large concentration of emitted hazardous substances. Location; when different types of hazardous substances are emitted, the sampling points shall be set at the working location of the equipment emitting hazardous substances to be measured, and the number of sampling points shall be determined by referring to the previous item.
When workers work in multiple work locations, set up a sampling point at each work location.
When workers work in a mobile manner, a sampling point is generally set up every 10 meters within the mobile range.
At least one sampling point should be set up in the instrument control room and workers' rest room.
4.3 Selection of fixed-point sampling period
Sampling must be carried out under normal working conditions and environment to avoid the influence of human factors.
For workplaces where the concentration of harmful substances in the air changes with the seasons, the season with the highest concentration of harmful substances in the air should be selected as the key sampling season.
During the working week, the working day with the highest concentration of harmful substances in the air should be selected as the key sampling day.
During working days, the period with the highest concentration of harmful substances in the air should be selected as the key sampling period.
5 Individual sampling
5.1 Selection of individual sampling objects
Sampling objects should be selected based on the on-site investigation and the purpose and requirements of the test.
In the course of work, all workers who are exposed or may be exposed to harmful substances are included in the sampling scope.
The sampling objects must include workers in different positions who are exposed to the highest concentration and longest exposure time to harmful substances. The remaining sampling objects should be randomly selected.
5.2 Determination of the number of individual sampling objects
When it is possible to determine the workers with the highest concentration of hazardous substances and the longest exposure time within the scope of the sampling objects, press the button for each job position Table selects the number of sampling objects, which should include workers exposed to the highest concentration of hazardous substances and the longest exposure time. When the number of workers in each job position is less than 3, all are selected as sampling objects.
Determination of the number of individual sampling objects (continued)
When it is impossible to determine the workers exposed to the highest concentration of harmful substances and the longest exposure time within the sampling object range, each job position Select the number of sampling objects according to the table below. When the number of workers in each job position is less than 6, all are selected as sampling objects.
6 Sampling where the occupational exposure limit is the highest allowable concentration
Use fixed-point, short-time sampling methods for sampling; select representative sites with the highest concentration of harmful substances in the air The working place is used as a key sampling point; sampling is carried out during the period when the concentration of harmful substances in the air is the highest; the sampling time generally does not exceed 15 minutes.
7 Sampling where the occupational exposure limit is the allowable concentration for short-term exposure
Use fixed-point, short-time sampling methods for sampling; select representative concentrations of harmful substances in the air The highest working location is used as a key sampling point; sampling is carried out during the period when the concentration of harmful substances in the air is highest; the sampling time is generally 15 minutes; when the sampling time is less than 15 minutes, more than one sampling can be carried out;
8 Occupations Sampling where the exposure limit is the time-weighted average allowable concentration
Based on the presence of hazardous substance concentrations in the air in the workplace or the operating performance of the sampling instrument, you can choose individual sampling or fixed-point sampling, long-term sampling or short-term sampling. Time sampling method. Mainly individual sampling and long-term sampling.
8.1 Sampling using the individual sampling method
Generally, the long-term sampling method is used. Select representative workers who are exposed to the highest concentration of harmful substances in the air as key sampling objects. Determine the number of sampling objects according to individual sampling requirements.
8.2 Sampling using the fixed-point sampling method
Sampling when workers are working at one work place
Sampling when workers are working at more than one work place or moving
8.2.1 Sampling when workers are working at a workplace
Long-term sampling method: Select a representative workplace with the highest concentration of harmful substances in the air as a key sampling point ; When the sampling instrument can meet the requirements of continuous one-time sampling throughout the working day, one sampling can be carried out throughout the working day; when the sampling instrument cannot meet the requirement of continuous one-time sampling throughout the working day, sampling can be carried out throughout the working day according to the operating time of the sampling instrument. Carry out 2 or more samplings within a period. Short-term sampling: Select representative workplaces with the highest concentrations of harmful substances in the air as key sampling points; conduct sampling at periods with different concentrations of harmful substances in the air; and record the working hours of workers in each period, and take samples The time is generally 15min.
and Record the working hours of workers at each sampling point;
At each sampling point, sampling should be conducted during the period when the concentration of harmful substances in the air is highest when workers are working;
Every time The sampling time is generally 15min.