APA (7th ed.) Citation

National Fire Protection Association. (2004). NFPA 497 recommended practice for the classification of flammable liquids, gases, or vapors and of hazardous (classified) locations for electrical installations in chemical process areas (2004 ed.). National Fire Protection Association.

Chicago Style (17th ed.) Citation

National Fire Protection Association. NFPA 497 Recommended Practice for the Classification of Flammable Liquids, Gases, or Vapors and of Hazardous (classified) Locations for Electrical Installations in Chemical Process Areas. 2004 ed. Quincy, MA: National Fire Protection Association, 2004.

MLA (9th ed.) Citation

National Fire Protection Association. NFPA 497 Recommended Practice for the Classification of Flammable Liquids, Gases, or Vapors and of Hazardous (classified) Locations for Electrical Installations in Chemical Process Areas. 2004 ed. National Fire Protection Association, 2004.