Spray painting not only is an emission source of solvent vapours but also of aerosols, which contain solid lacquer elements such as pigments, fillers etc. and solvents. At present, there is no way of assessing workplaces in view of this aerosol exposure. On demand of some of its members, the sub-committee V limit values of the German hazardous substances committee (AGS) decided to investigate whether or not it would be possible to define a technically founded limit value. To enable the necessary exposure measurements, suitable measuring methods were developed and comparatively tested in a joint effort by the BG Institute for occupational safety - BIA, the Federal institute for occupational health and safety and work medicine and the Institute for hazardous substances research of the Berufsgenossenschaft for the mining industry. The methods and results obtained in the test series are set out hereinafter.