The tendency for the press and public to over-react on safety. The need to balance risk against benefit. The difference between hazard and risk. Preventative or protective steps (control measures) to reduce the risk from particular hazards. Examples in school science, including the use of eye protection and alternative strategies, if eye protection is not available. The ability of teachers to supervise a class dependent on the size of the class. The need for supervision dependent on the nature of the practical activity and the risk involved in it, as well as the nature of the class, and the skills and behaviour of the students. (Contains 1 footnote.)