The general dust limit value. Part 1: General remarks

The newly applying general dust limit value, defined by the Deutsche Forsch ungsgemeinschaft (DFG) (German Research Association) in 1997, is intended t o prevent work-related chronic bronchitis and pulmonary emphysema. In addit ion to a revised general dust limit for the respirable fraction, which was lowered from 6 mg/m(3) to 1.5 mg/m(3), the experts introduced, for the very first time, a limit value for the inhalable fraction, too, which was fixed at 4 mg/m(3). Both limit values are not meant as long-term limits but as s hift means. Both MAK-values apply to insoluble dusts for which no other reg ulation exists, or to mixed dusts. As these suggestions are about to be inc luded in the German TRGS 900 "Atmospheric limit values", the authors presen t and discuss special aspects in connection with the scientific deduction o f the limit values and with their scopes of application. Reference is made to the role of confounders and dust density, to the question of solubility, to the deduction of shift means from long-term limits and to the problem o f ultrafine and roughly dispersed particles. International regulations rela ting to the general dust limit value are compared.