Implementation of the precautionary principle in standards for the workplace

The objectives were to describe and discuss the current and proposed European occupational health policy on two categories of substances that pose serious effects: those potentially carcinogenic or genotoxic and those with toxic effects on reproduction. The precautionary principle was applied to setting standards for the workplace for those two categories of substances, to give an impression of the resulting limit values and the consequences of the implementation of this precautionary principle. A pragmatic approach was chosen as this starts with substantial indications of health risks. For the suspected carcinogenic or genotoxic substances 0.1 mg/m3 as a precautionary occupational exposure limit (precautionary OEL) is proposed. For the substances suspected of causing reproductive toxicity the precautionary OEL was derived in three ways, depending on the availability of data and of a current Dutch workplace standard (MAC, maximum accepted concentration): (a) by calculation based on available inhalatory animal data on the risks of reproductive toxicity; (b) by adding a safety factor of 10 to the current MAC, if no inhalatory animal data on reproductive toxicity are available; (c) by using 0.1 mg/m3 as precautionary OEL for substances suspected of having reproductive toxicity but without inhalatory animal data on reproductive toxicity and without a MAC.