Marking Hazardous (Classified) Locations is a critical step in both compliance and personnel safety. While OSHA and the NEC (NFPA 70) mandate the classification of these areas, they are surprisingly quiet on exactly how to physically mark them.
Because “invisible” hazards like flammable vapors or combustible dust can’t be seen, you should use a tiered approach to ensure anyone approaching the area knows the risks. Members can download my written program for “Demarcating HAZLOCs” at the end of this article.