Percutaneous penetration studies for risk assessment

During the last few years the general interest in the percutaneous absorpti on of chemicals has increased. It is generally accepted that there is very few reliable quantitative and qualitative data on dermal exposure to chemic als in the general population and in occupationally exposed workers. In ord er to predict the systemic risk of dermally absorbed chemicals and to enabl e agencies to set safety standards, data is needed on the rates of percutan eous penetration of important chemicals. Standardization of in vitro tests and comparison of their results with the in vivo data could produce interna tionally accepted penetration rates and/or absorption percentages very usef ul for regulatory toxicology. The work of the Percutaneous Penetration Subg roup of EC Dermal Exposure Network has been focussed on the standardization and validation of in vitro experiments, necessary to obtain internationall y accepted penetration rates for regulatory purposes. The members of the Su bgroup analyzed the guidelines on percutaneous penetration in vitro studies presented by various organizations and suggested a standardization of in v itro models for percutaneous penetration taking into account their individu al experiences, literature data and guidelines already in existence. During the meetings of Percutaneous Penetration Subgroup they presented a number of short papers of up to date information on the key issues. The objective was to focus the existing knowledge and the gaps in the knowledge in the he ld of percutaneous penetration. This paper is an outcome of the meetings of the Percutaneous Penetration Subgroup and reports the presentations on the key issues identified throughout the 3-year duration of the Dermal Exposur e Network (1997-1999). (C) 2000 Elsevier Science B.V. All rights reserved.