The invention provides a method for estimating the dermal transfer efficiency of a chemical substance comprising a step of determining a calculated value for the dermal transfer efficiency for the time elapsed after use of the chemical substance, based on a formula wherein the temporal change in the dermal transfer efficiency is expressed as a function dependent on the \u22120. At least portions of the surface of the main blade section are provided with at least one first protective coating comprised of oxidation-resistant material, the first, oxidation-resistant coating is a metallic coating, which is optionally covered by a ceramic thermal barrier coating. The method allows a Fresnel layer to be defined that compensates for geometric effects induced by a variation in the curvature of the carrier on the light incident on the face of an ophthalmic lens. Fight and assault control sub-modes may be provided. By eliminating direct dependencies between the partitions and the partitionable keys, the system can have great flexibility with regard to migrating customer data between partitions and adding a new partition.