Assessment of Exposure to Chemical Agents

Determination and assessment of the risks of hazardous chemical agents requires knowledge of, among other things, the nature of the agents, the type and duration of the exposure, the gravity of risk, and the criteria chosen for the OEL. The purpose is to make quantitative measurements of the work environment in order to compare the exposure with the limit value by means of an independent scientific assessment using the best available scientific methodol- 

However, assessing occupational exposure to airborne contaminants in a representative way is not an easy task and requires a good deal of professional judgment and reliance on a good methodology. There are many issues to be resolved, such as 

This implies, for example, that measurements taken over a given period of time may give insufficient data to integrate workplace factors in the series of activities in the period under consideration in such a way as to permit assessment of the likely maximum risk to which the individual workers are exposed. 

T he standardized procedure for evaluation of exposure to chemical agents is done in three steps  

The first step is to identify the substances present at the workplace. As a starting point, knowledge of the process is needed in order to formulate a list of all chemical agents used in the establishment. The list should include not only primary products but also intermediate and final products, as well as reaction products and by-products. For the chemical agents in the list, it is necessary to know their chemical properties, especially hazardous ones their OEL values, including biological limit values and, where these are not available, other technical criteria that can be used to evaluate the risk. It is also helpful to include any information on the safety and health risks of those substances provided by the supplier or other readily available sources. This information on dangerous substances and preparations, in the form of safety data sheets, is intended primarily for industrial users, to enable them to take the measures necessary to ensure the safety and health of workers. 

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European Committee for Standardization. EN 689 1. Workplace atmospheres Guidance for the assessment of exposure to chemical agents for comparison with limit values and measurement... 

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