
17. 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; 2008, Paragraph 3.3.9. National Fire Protection Association;
Quincy, MA.
18. 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; 2008, Paragraph 3.3.10. National Fire Protection Association;
Quincy, MA.
19. NFPA 70, National Electrical Code
; 2005, Article 500.6(A)(1) and 505.6(A), (B), and
(C). National Fire Protection Association, ...