As we celebrate 50 years of the BTS, it is timely to consider what topics and challenges dominated our thinking in toxicology 50 years ago and how things have evolved to the current day. To gain insight into this, we sought the views of several senior toxicologists who offered their observations and reflections on their careers in toxicology. One notable trend is the changing skill sets that might be considered essential for a career in toxicology. Fifty years ago, experience of in vivo methodologies was expected whereas today’s recruits into toxicology rarely have this skill set. In contrast, in silico “and” in vitro (ISIV) methods such as molecular biology and computational methods dominate our approaches; a working knowledge of bioinformatics and computational approaches would be expected today but unheard of 50 years ago (Fig. 1). Another emerging theme is the need to make decisions based on limited data. This is well illustrated by experiences shared by Dr Diane Benford. “Whether you are working on naturally occurring compounds and toxins or those arising from human activity, you have to make decisions on limited data, with no possibility of asking a manufacturer to perform more studies.” Indeed, regulatory toxicology studies conducted according to internationally agreed guidelines are commonly not available and it would often be hard to justify conducting or repeating such work. In the early days of her research, Dr Sue Barlow’s research topic was potential changes in brain function after prenatal exposure to drugs. “The challenge was to work out if any of the animal cognitive behaviour techniques could be applied to very young animals, and how to interpret the results,” she explained. Professor Faith Williams also pointed out that today we often rely on data that could have been generated 40 or 50 years ago “A good example of this is our dependency on legacy data on skin absorption, requiring us to have robust methodologies for extrapolation.”