Human factors behind the improved ANSI Z535.3 label standard for Safety Symbols

The 1997 revision to the ANSI 2535.3 Criteria for Safety Symbols standard refined and expanded the structure of the original 1991 version. The revision contains improved symbol creation guidelines, comprehension test procedures, symbol surround shape and color guidance, and symbol examples. This paper explains the revisions of interest, the role of human factors analyses in driving the standard's evolution, and the reasons why symbols created and tested according to the revised criteria are expected to be more effective in terms of consistency, legibility, and most importantly, comprehension. Research areas for future revisions are also identified.