ABSTRACT
Here we review the use of signal words to quantify the hazard implied by a warning. For signal words presented as text, we consider what the standardization groups and the research evidence has to say about which precise words should be used to denote specific levels of hazard. In addition, we will consider the generalizability of the hazard associations found and how they interact with color. We also consider how hazard associations for auditory presentations of signal words mirror those found for text presentations, and how acoustics, phonetics, and speaker gender all interact to influence the perceived hazard of spoken signal words.
