Introduction‎ > ‎

What is and isn’t a warning?

A caution (e.g., drink responsibly) or warning (e.g., may cause cancer) does not have a universally accepted definition but is usually associated with labelling that appears on a product (on-product), within product packaging or at the product's place of use. Our project only considers on-product warnings. Alcohol warning labels are currently mandatory in 31 countries (WHO, 2014).

A useful formal definition of a warning is provided by Lehto and Miller (1986, p.14) who state that “warnings are those stimuli that alert people to hazardous conditions”.


Inherent to the definition of a warning, is the question as to their function.  Warnings are generally about information provision highlighting potential risks (or more detailed information about the magnitude of the risk) that helps consumers to weigh up whether or not they should use the product (e.g., take a particular medicine).  Warnings may also include information about how to use the product safely (e.g., operate a drill) or how to mitigate the risk associated with use of the product (e.g., by keeping to a threshold).  Some would argue that warnings have the potential function of behaviour change, thus beyond providing information, the information should be processed and the consumer should change behaviour (if necessary) to comply with the warning.  In determining whether or not a warning is effective, there is a need to be clear on its purpose.


Lehto, M.R., and Miller, J.M. (1986), Warnings: Fundamentals, Design, and Evaluation Methodologies. Ann Arbor, MI: Fuller Technical Publications.  


World Health Organization (2014), “Global status report on alcohol and health 2014,” see