The procedure for measuring dermal exposure to chemicals at the workplace is not standardised. There has been a lack of sufficient scientific research on measurement methods which compares various methods by means of systematic measurements.

For this reason, experiments on dermal exposure to chemicals at the workplace were carried out within the SysDEA project and were subject to the following variations. Three fundamentally different measurement principles: 1) interception of chemicals (whole body dosimetry (WBD) using coveralls, gloves, patches), 2) removal by wiping or washing and 3) In situ by fluorescence measurements. Different test substances (low and high viscosity liquid, dusty solid) were used for various activities (transfer, spreading, spraying, immersion/dipping, handling of contaminated objects), and the resulting exposure of different parts of the body (hands, body, head) was investigated. The experiments were carried out four times by each of four volunteers.

For hand exposure, higher exposure values were measured by interception with gloves, especially when rolling low viscous liquids and when manually handling objects, than with the hand washing method. This tendency was also apparent for the other activities, but less pronounced. To obtain conservative assessments of hand exposure, measurements with the glove method are advantageous.

For body exposure, interception with patches resulted in higher exposure levels than interception by coveralls for all activities with liquids, except rolling. No significant difference was found for powders. Since patches measure exposure on small but representative areas, measured values must be extrapolated to the body or coverall surface. Depending on how the area sizes were chosen for extrapolation, the final body exposures obtained were higher or lower than those obtained by WBD. A binding definition of the extrapolation method should be developed within the framework of standardization.

The variation of measured values depends on the exposure pattern and thus on the activity, but generally does not depend on the method. It is lower for uniform expo-sure patterns than for non-uniform exposure patterns dominated by splashes. This applies to patches as well as to coveralls. Therefore, more measurements may be required if the pattern is uneven. The difference between the values measured with patch and WBD was minor.
The body exposure determined with the fluorescence method used in the project is considerably lower than that determined by the other methods. This fluorescence method therefore appears to be less conservative, but can help to determine the exposure pattern on the body. This is helpful in determining a measurement strategy.