1. NFPA 69(2019).Standard on explosion prevention systems. Quincy MA: National Fire Protection Association.
2. IEC 60079‐7(2015).Explosive atmospheres – Part 7: equipment protection by increased safety ‘E’. International Electrotechnical Commission.
3. NFPA 497(2012). Recommended Practice for the Classification of Flammable Liquids Gases or Vapors and of Hazardous (Classified) Locations for Electrical Installations in Chemical Process Areas. Quincy MA: National Fire Protection Association.
4. Chemical Safety Board.www.csb.org.