Whole body vibration measurements and calculations of the daily 8-hour values in Finnish working environments

The European Union Physical Agents Directive (vibration) sets vibration exposure limits for an employer. The measured values from different work phases should be time weighted and summed together to represent a daily 8-hour exposure value. The directive has two limit values, the daily exposure action value and the daily exposure limit value. For the employer the greatest concern is to comply with the exposure limit value, but also exceeding the action value will cause implications. To calculate the daily 8-hour value is not a simple task, because there are normally several different work phases that the worker does in a normal day. Also the assessment of measurements of the vibration levels have to be made in real working environments. The work phases need to be calculated correctly to get the representative daily value. Also breaks and other non-work operations need to be included. This will make the complete assessment very difficult without proper knowledge. In this study a large number of measurements from different mobile work machines were made to establish whether the daily values would exceed the limit values. Analyses were made using three examples to show how the employer can use the standard and directive to assess the daily exposure values or times. The results were largely dependent on the work pattern and the dominant levels.