The risk assessment for workers handling hazardous substances is based on the evaluation of substance-intrinsic properties and the occupational exposure assessment.
Currently the measuring methods for occupational dermal exposure are not harmonized. For existing measurement methods scientific studies are missing concerning the evaluation of significance and applicability. There is a lack of systematic investigations carried out by means of different measurement methods for the determination of dermal exposure. Especially information concerning the comparability of measurement results from different methods is missing. Additional there is a need for a better investigation how far a measurement method takes into account the physical and chemical properties of the individual hazardous substance.
There is an open question, which measurement method would be the most suitable for which task. In addition, the comparability of results from different measurement methods will be investigated.
For this purpose the dermal exposure of probands performing selected tasks under defined and standardised conditions is to be determined in test chambers. The dermal exposure will be quantified for different exposure situations (task + ambient conditions + substance) by various measurement methods respectively.
The overall objective of the SysDEA study is to generate scientific knowledge for improvement and standardization of measurement methods for dermal exposure to chemicals at the workplace. To this end, five different tasks (transfer, spreading, spraying, handling immersed objects, and handling contaminated objects) were performed with three different product types: a dusty powder (solids) and high viscosity (HV) and low viscosity (LV) liquids. The investigated exposure situations (product-task combinations) were: dumping powder, pouring LV and HV (transfer), rolling LV and HV (spreading), surface spraying LV and HV (spraying), manually handling objects immersed in LV and HV (immersion/dipping) and handling objects contaminated with powder. The measurement methods investigated were: whole body dosimeter (coverall) versus patches for body exposure, gloves versus hand wash for hand exposure, and head bands versus head wipes for head exposure. In addition, a fluorescence method was used for all body parts. Each of these exposure situations was performed four times by four different test subjects each for all of the three different measurement methods (including body, hand and head exposure). In total 320 individual experiments were performed.
Statistical analysis of the measurement results led to the following results:
For body exposure, the patch method resulted in higher measured exposures than the use of overalls for exposure situations with liquids, except for rolling. No significant difference was found for powders.
For hand exposure, significantly higher exposure values were measured with the glove method for rolling and manually handling objects with liquids. For spraying and pouring, also higher values were measured with the glove method compared to the hand washing method, but these differences were not statistically significant. In the case of exposure situations with powders, the glove method resulted in significantly higher exposure values for handling contaminated objects, but not for dumping powders.
For head exposure, the wipe method resulted in higher values than the headband method, except for spraying and rolling, where no significant difference was observed.
Estimates of body exposure using the fluorescence method resulted in severely lower exposure values compared to the methods based on chemical analysis for both liquids and powders.
Unit 4.1 "Exposure Scenarios"