Thomas Pfister, B.Sc., Ph.D. is EUROTOX Registered Toxicologist and scientific expert at F. Hoffmann-La Roche in Basel. He has more than 25 years of experience as a research scientist, pharmacologist, and toxicologist in CRO, pharmaceutical, and chemical industries. In his current position as occupational health officer in a corporate function he is responsible for setting health based limits for workplace air concentrations of chemicals and active pharmaceutical ingredients worldwide. When in 2010 Roche Quality Assurance decided to introduce the principle of Acceptable Daily Exposure (ADE) for use in cleaning validation of equipment in multi-product facilities, he developed the strategies and processes for implementing the ADE concept at Roche in 2011. Since then, he is leading a group of specialists in charge of transferring the ADE concept to the whole portfolio of Roche.