The effect of adding symbols to written warning labels on user behavior and recall

A study was conducted to determine the effects of adding a warning symbol to a consumer product warning, familiarity with the product, and the type of hazard associated with the product on warning conspicuity, user behavior, and recall. One hundred forty-four college students used consumer products and direct observation of compliance with the warning was measured. A follow-up questionnaire was used to determine the number of subjects who noticed, read, and recalled the warning, as well as to obtain subjective ratings of perceived confidence, perceived hazardousness, perceived likelihood of injury, and perceived severity of injury. Across all behavioral measures, there was a steady decline in the number of subjects who first noticed, then read, and finally followed the warning. Overall, warnings were shown to be effective about 25% of the time, although in some conditions compliance levels were as high as 42%. Including a symbol on the labels of the products was not found to significantly affect compliance. A significant label type x hazard type interaction for noticing and recalling the warning symbol indicated that symbols warning about an eye contact hazard are best noticed and recalled when a reactive symbol is used, while symbols warning about an inhalation hazard are best noticed and recalled when a proactive symbol is used. A significant, positive relationship was found between the perceived hazardousness of a product and reading, following, and recalling the warning. A significant, positive relationship was also seen between the perceived likelihood of being injured and compliance. Placing the warning information regarding the appropriate precautionary action(s) first in the warning section and adding a well-designed symbol to the warning were two design recommendations made. Factors associated with the users' motivation to read and follow on-product warnings were also discussed.