John obtained his first degree in Zoology from the University of Wales in 1975 before undertaking research, on liver pathology, for which he was awarded a PhD in 1978. He then joined the British Industrial Biological Research Association (BIBRA), at Carshalton in the UK, as an experimental pathologist and head of the electron microscopy unit. He left BIBRA in 1983 to join the Pathology Department of ICI Central Toxicology Laboratory in Cheshire, United Kingdom. He obtained a diploma of the Royal College of Pathologists (RCPath) in Toxicology in 1987 and passed the examination to become a member of the RCPath in 1988 and was elected a Fellow in 1997. He was chairman of the Specialty Advisory Committee for Toxicology for the RCPath from 2002–2005 and was Chair of the Panel of Examiners for the Toxicology Specialty of the RCPath from 2006–2012. He remains an examiner for the College.
He was a science–reviewing member of ECETOC’s Long Range Research Initiative on Carcinogenicity from 2000–2006 and he sat on the UK Food Standard Agency’s Committee on Toxicity from 2006–2012. He was President of the British Society of Toxicological Pathologists from 2002–2004 and was appointed a Fellow of the British Society of Toxicology in 2008. He was a visiting lecturer, and was made an Emeritus Professor in the Faculty of Faculty of Health and Medical Sciences at the University of Surrey in 2010 and was made an Honorary Fellow of the BSTP in the same year. In 2011 he was made an Honorary Fellow of the Latin American Society of Toxicologic Pathologists and became a Fellow of the International Academy of Toxicologic Pathology in September 2012. He was elected President of the International Academy of Toxicologic Pathology from 2019-2021.
Prof Foster has published over 150 research papers, review articles, and book chapters in toxicological pathology, and was the Editor in Chief of the journal, Toxicologic Pathology, from 2008–2013. Following 20 years working on the development of agrochemicals and industrial chemicals, at ICI, Zeneca and finally Syngenta’s Central Toxicology Laboratory, he joined AstraZeneca Pharmaceuticals in 2001 specializing in the development of oncology targeting drugs. He retired from AstraZeneca in 2013 as a Senior Principal Pathologist and Deputy Head of Pathology. He is currently an independent consultant pathologist working for an independent pathology consultancy company called ToxPath Sciences Ltd.