Evaluation of systemic health effects following dermal exposure to chemicals
Technical Report no.119. Evaluation of systemic health effects following dermal exposure to chemicals
Exposure to chemicals can occur through the mouth, nose or the skin. While a lot of work has been done studying health risks of chemicals taken up through the mouth and nose, less has been done on health risks caused by chemicals getting into the body through the skin. Chemical legislation, most notably REACH, does however require information on possible health risks from dermal exposures. This ECETOC Report has therefore been developed to provide a step-wise approach for assessing and understanding health risks of substances that get onto the skin either as a solid, a liquid or when sprayed as an aerosol.
The value of the ECETOC document is that it uses a decision-tree type approach that can be used by both experienced and less experienced scientists to provide relatively simple, or if necessary refined, estimates of health risk. Several examples are provided guiding the reader through the step-wise approach. While the document is mainly for skin exposures occurring in the work place, it can also be used by those scientists interested in assessing risks from skin exposures in other settings.
Risk assessment of chemicals, including the REACH (Registration, Evaluation, Authorisation and Restriction of Chemicals) legislation, also cover assessments of dermal risk arising from exposure to chemicals. The European Centre for Ecotoxicology and Toxicology of Chemicals (ECETOC) has produced this guidance consisting of a tiered approach for the risk assessment of dermal exposure to a chemical.
The process developed by the Task Force consists of three linked decision trees, i.e.:
- Derivation of a health-based reference value.
- Initial risk characterisation.
- Refined risk characterisation.
It is designed to use existing exposure and toxicology data and identify data gaps or data inadequacies to be addressed to complete a risk assessment.
Each component of the decision trees is supported by explanation in the text and, in relevant cases, by an appendix providing additional detailed background information. This allows users with varying amounts of experience in risk assessment to access the guidance at different levels.
The decision trees are structured to allow early identification of potential data gaps and to provide guidance on a variety of options such as acquiring basic toxicology data, the use of QSAR/computer-based predictions or the generation of dermal absorption data. Options for the refinement of exposure assessment range from revising parameters in the models to the conduct of bio-monitoring studies in exposed individuals. The process of a tiered approach can be ended at any stage depending on the outcome of the risk assessment. All non-animal refinement options should be considered to allow the potential demonstration of an adequate margin of safety in risk assessment before opting to perform new toxicology/ADME tests in animals.
Several case studies are presented to illustrate how the decision process can be utilised.