Professor Jon Heylings was invited by the British Toxicology Society to write a historical perspective on the development of the OECD test guidelines 427 and 428, used for the measurement of dermal absorption. This is a featured article in the latest BTS Newsletter. DTL scientists developed much of the in vitro methodology in this area of safety assessment. Jon was the industry member of the OECD Expert Committee who wrote the test guidelines and OECD Guidance Document No. 28 on behalf of the European Crop Protection Association Toxicology Expert Group in the 1990s. Here is the link to the latest edition of the BTS Newsletter.