What is a Warning and When Will it Work?

The term warning is applied to a variety of stimuli. From a safety standpoint, the most appropriate definition of warning ties it to any information that has the potential to change behavior and prevent accidents. The results of an extensive literature review suggest that warnings are unlikely to be effective unless a series of conditions are met. The failure of many intended warnings, including most on-product warning labels, to reduce accidents reflects the difficulty of overcoming the problems inherent in their use.