Documents Pronk, M.E.J. 2 results

An evaluation was performed on the first group (41) of completed risk assessments for chemicals of the EU priority lists (Existing Chemicals; EC Regulation 793/93). The evaluation focussed on the conclusions of the risk assessments. The EU risk assessment process detected a high number of substances of concern. Furthermore priority chemicals may pose (potential) risks to the whole range of protection goals of the risk assessment. The predictability of the risk assessments for priority chemicals was investigated. Our a priori knowledge on possible risks of priority chemicals is found to be poor, especially for consumers. Both for environment and human health the (potential) risks were linked with a broad spectrum of use patterns. It is concluded that no industry category can in advance be excluded from performing risk assessments. For a great number of chemicals, additional testing was found to be needed to finalise the risk assessment. This evokes questions about the completeness of the current base-set, but also about the suitability of some of the submitted human health tests that should initially fulfil the base-set needs. The results of this evaluation are useful for future discussions on risk assessment processes for chemicals.

"Workers can be exposed to chemical agents. In order to assure that this exposure will not result in adverse effects on health, occupational exposure limits (OELs) are established. In general this means that a safe level of exposure via the airborne route is set such that this exposure, even when repeated on a regular basis throughout a working life, will not lead to adverse effects on the health of exposed persons and/or their progeny at any time.
For the group of carcinogens which directly damages DNA, a different approach is needed. For these so-called non-threshold carcinogens it is not possible to derive a level of exposure at which no adverse health effects may occur; it must be assumed that any level of exposure, however small, might carry some finite risk. Occupational exposure limits for this type of substances are derived using a 'risk level': the number of additional cases of cancer due to exposure to such substances. The Ministry of Social Affairs and Employment requested the RIVM to make an inventory of the methodologies which are applied in the EU to derive OELs for non-threshold carcinogens.
It was found that there are many similarities, but also some differences. One of the similarities is that the methodologies are based on similar principles. All apply similar general criteria for quality and adequacy of the data selected to derive the limits. All also prefer the use of human data above the use of animal data, but recognize that in most cases these will not be available or will not form a sufficient basis on their own.
Differences observed in occupational exposure limits for non-threshold carcinogens are largely due to differences in cancer risk levels used. Other sources for the differences are the choice for the animal exposure levels which causes the adverse effect, and uncertainty factors applied in the extrapolation from animals to humans. When at a later stage other considerations such as socio-economic or technical feasibility are also taken into account, these may additionally lead to differences in the final occupational exposure limits."