SYMBOLS FOR INDUSTRIAL SAFETY

Written signs are commonly used in industrial sites to provide hazard warnings and safety information. The use of safety symbols may increase the effectiveness of safety communication, because such signs are language-free, and because they can be recognized more rapidly and accurately than written text even under some conditions of interference and distraction. The effectiveness of safety symbols critically depends upon the selection of symbolic images which are readily understandable to the intended audience. A four phase evaluation of a set of selected industrial worksite symbols is described. The four phases involved identification of 33 key safety messages, selection of candidate symbols for each message, evaluation of the understandability of the candidate symbols, and determination of the preference for the 87 candidate images, using both industrial and nonindustrial (naive) personnel. Symbol understandability, in terms of percentage of correct responses and confusions, varied widely for the thirty-three referents. Despite standardized use or a number of years, the radiation, biohazard, and laser symbols were frequently misidentified. Symbols for protective gear, first aid, and emergency equipment were generally correctly identified. The different images selected for various hazards show the greatest range in understandability, with the results for symbolic versions of entanglement, electricity, corrosion, and overhead hazard being quite different. The preference data generally support the understandability data, with the most correctly identified image usually being the most preferred image. Participants also provided insightful comments about the reasons for their choices, including ideas about the visibility, representativeness, and effectiveness of the images proposed for each referent.