Guidance on dermal absorption

This guidance on the assessment of dermal absorption has been developed to assist notifiers, users of test facilities and Member State authorities on critical aspects related to the setting of dermal absorption values to be used in risk assessments of chemical plant protection products. It is based on the opinion on the science behind the revision of the guidance document on dermal absorption (EFSA, 2011) to which the guidance refers to in many instances. Basic details of experimental design, available elsewhere, have not been addressed but recommendations specific to performing and interpreting dermal absorption studies with plant protection products are given. Issues discussed include a brief description of the skin and its properties affecting dermal absorption. To facilitate use of the guidance, flow charts are included. Guidance is also provided, for example, when there are no data on dermal absorption for the product under evaluation. Elements for a tiered approach are presented including use of default values, data on closely related products, in vitro studies with human skin, data from experimental animals (rats) in vitro and in vivo and the so called "Triple pack" approach. Various elements of study design and reporting, that reduce experimental variation and aid consistent interpretation, are presented. A proposal for reporting data for Draft Assessment Reports and Registration Reports is also provided. The issue of nanoparticles in plant protection products is not addressed. Data from volunteer studies have not been discussed since their use is not allowed in EU for risk assessment of plant protection products.