BS EN 689:2018 pdf free.Workplace exposure – Measurement of exposure by inhalation to chemical agents – Strategy for testing compliance with occupational exposure limit values.
This European Standard deals with the measurement of exposure to chemical agents in workplace atmospheres, and in particular with measurement strategy for comparing workers’ exposure by inhalation with occupational exposure limit values (OELVs). Other parts of management of exposure of workers are not dealt with in detail in this European Standard.
Within this European Standard, compliance means that workers’ time weighted average workplace exposure is below an OELV with a corresponding reference period. OELVs include legal values and other numerical criteria (see Annex B).
Representative measurement of workplace exposure to chemical agents is difficult, because of the variability of exposure. Processes and products affecting exposure are nunwrous. Different workplace conditions can correspond to different generation rates, can involve a variety of chemical agents and can therefore present specific exposure conditions. Exposure can be affected by the distance of the exposed workers from emission sources; and parameters such as emission intensity, ventilation, climatic conditions, seasonal variations and the controls applied can also have a very marked influence. The spatial and temporal variabilities of exposure conditions are further enhanced by workers’ practices and activities themselves.
The sampling equipment introduces its own limitations, and the analytical steps add further difficulties and uncertainties.
This European Standard is applicable for measuring procedures that fulfil the requirements of EN 482. If a measuring procedure does not fulfil these requirements some parts of the procedure described in this European Standard cannot be applied.
To assess the exposure of workers to chemicals and to state with certainty that it does not exceed the OELVs (short-term or long-term) would require measurement of the exposure of every worker for every working day. Unfortunately while this approach is possible for some agents such as ionizing radiation, it is not feasible or practical for many chemical agents due to limitations of the measurement techniques and costs.
The strategy described in this European Standard gives a procedure for the employer or other stakeholdcrs to overcome the problem of variability and to use a relatively small number of measurements to demonstrate with a high degree of confidence that workers are unlikely to be exposed to concentrations exceeding the OELVs. To reduce the number of exposure measurements, and therefore the cost of assessment, personal air samples are collected among workers within similar exposure groups (SEGs). A single measurement or even several measurements below the limit value can be insufficient to reliably demonstrate compliance without using a statistical test like the one proposed in this European Standard.
Respiratory protective equipment (RPE) is used to reduce the amount of the chemical agent that is inhaled by the worker. However, this European Standard does not take into account the use and effectiveness of RPE in testing compliance with the OELV.
Before any measurements are performed, it is essential for an appraiser to conduct a basic characterization in order to collect relevant information on workplace factors, and the available information on exposure in the workplace concerned. This includes information on variation of exposure with time of day and season of the year, so that the measurement is representative.
If the basic characterization shows that exposure is probably higher than the OELV, then it is recommended to reduce exposure by risk management measures (RMM) before measurements are planned for compliance testing.
1 Scope
This European Standard specifies a strategy to perform representative measurements of exposure by inhalation to chemical agents in order to demonstrate the compliance with occupational exposure limit values (OELVs).
This European Standard is not applicable to OELVs with reference periods less than 15 mm.
2 Normative references
The following documents are referred to in the text in such a way that some or all of their content constitutes requirements 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.
EN 482, Workplace atmospheres — General requirements for the performance of procedures for the measurement of chemical agents
EN 1540, Workplace exposure — Terminology.BS EN 689:2018 pdf free download.