ABSTRACT
A warning, for present purposes, is a safety communication device that should be designed to attract attention to itself, to give information about a hazard, its degree of seriousness, its probable consequences and of the way in which those consequences can be avoided. This chapter will discuss what is known about the principles that determine the effectiveness of a warning. It will not deal with legal questions such as requirements for particular wording nor, except indirectly, with the question of when a warning should be used. In many countries there is legislation governing the design and use of warnings and such legislation will always take precedence. National standards associations, workplace safety organizations and consumer organizations are a good source of relevant information.
