Recommended Practice for the Classification of Flammable Liquids, Gases, or Vapors and of Hazardous (Classified) Locations for Electrical Installations in Chemical Process Areas
What is NFPA 497?
This recommended practice presents criteria to determine ignitability hazards in chemical process areas using flammable liquids, gases, or vapors to assist in the selection of electrical systems and equipment for safe use in Class I hazardous (classified) locations.
Official document scope
What does NFPA 497 address?
Users will gain a basic understanding of the parameters that determine the degree and extent of the hazardous (classified) location. Information is provided on specific flammable gases and vapors, flammable liquids, and combustible liquids whose relevant combustion properties have been sufficiently identified to allow their classification into the groups established by NFPA 70, National Electrical Code.
Table of Contents