The National Electrical Manufacturers Association (NEMA) has published ANSI Z535.1 through .6 and Color Chart for Safety Alerting Standards. The set is available for $480 at www.nema.org/stds/z535.
The Z535 series is valuable for those needing a comprehensive source of standards relating to the design, application, and use of safety signs, colors, and symbols. It is used by manufacturers of ink, pigments, and dyes for the safety sign industry, including sign, label and tag makers; designers of safety signs, labels, tags and tapes; and symbol comprehension testing programs.