Assessment framework for biological limit values

In order to protect employees against health problems caused by exposure to hazardous substances in the workplace, the Health Council of the Netherlands derives health-based Occupational Exposure Limits (OELs). These are concentrations of substances in the air at which it is assumed that no or limited health effects are expected. Based on these values, the Ministry of Social Affairs and Employment can set a legal limit value. The council has developed a scientific assessment framework to determine for which substances a biological limit value has added value compared to an air-based OEL.

For most hazardous substances, air-based OELs for the workplace are derived. However, sometimes this is not possible, and sometimes air-based OELs do not provide sufficient protection. Exposure can then be measured more accurately with biomonitoring in body material such as blood, urine or exhaled air. For those substances, biological limit values can be derived. With the assessment framework, the council can better decide and substantiate which type of limit value best protects the health of the employee. Both technical and ethical considerations play an important role in the framework. The council will include the assessment framework in its working method for assessing hazardous substances in the workplace.