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, which he left in 1983 to join the Pathology Department of ICI Central Toxicology Laboratory in Cheshire, United Kingdom. He became a member of the UK Royal College of Pathologists in 1988, was elected a Fellow in 1997, and ran the Specialty Advisory Committee for Toxicology from 2002-2005. He was Chair of the Panel of Examiners for the Toxicology Specialty of the RCPath from 2006-2012 and remains an examiner for the College.

He was a science-reviewing member of ECETOC’s LRI 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. He was appointed an Honorary Fellow of the British Society of Toxicology in 2008, was made an Emeritus Professor in the Faculty of Health and Medical Sciences at University of Surrey in 2010 and was elected as 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 of 2012.

Prof Foster has published over 130 research papers, review articles and book chapters in toxicological pathology, and was the Editor in Chief of the journal, Toxicologic Pathology from 2008-2013.

He worked for AstraZeneca Pharmaceuticals from 2001 until the end of 2013 as a Senior Principal Pathologist and Deputy Director of Pathology, joining RSA in January 2014.