Standard practice, endorsed by the Red Book of the American Association of University Professors, still tends to give disciplinary departments the loudest voice in the debate over whether a young scholar gets lifetime employment--or is fired.
"Mathematicians working together just talk through ideas or stare into space hoping to have one. Sometimes they go for a walk. This is particularly pleasant if the walk happens to be through Paris streets or along cliffs overlooking the Mediterranean Sea. Fresh air is essential, especially if one of them smokes." --Ernest Schimmerling
"We felt very well established in what we were working on in our postdocs and really excited about new opportunities and looking for ways to make those new opportunities come into being." - Alexis Templeton
"From its inception, the Career Development Center for Postdocs and Junior Faculty (CDC) has aimed to fill this deficit by educating young researchers in the large body of nonscience knowledge that young academic scientists need to advance their careers and the research infrastructure of the United States."
Just about every experimental science trainee experiences some variation on this theme: Their work entails a variety of risks in combination, they have little experience in dealing with those risks, and--much of the time--safety considerations take second place to getting the work done.