Hazardous Area Classification


  • Identifying a potential source of release and considering the quantities that can be released.
  • Grading the source of release as per the Indian Standard.
  • Finding out and suggesting possible ways of reducing the grade of release and eliminating the source of release.
  • Evaluating the parameters which can affect the type and extent of zoning.
  • Suggesting controls such as ventilation, pressurization etc,
  • Optimizing to maximum possible amount the requirement of controls.
  • Determining the level of protection for electrical equipment required for each zone.

Scope of HAC

  • To assess the process and segregate the areas and chemicals (both vapour and dusts) that require zoning by Studying the process flow and analysing chemicals with aspect of Hazardous Area  classification of the plant with respect to IS 5572, IS 13408 , and relevant NFPA-Standards like 499, 497(if & when reference required) &94/9/EC (ATEX 95)etc.
  • To draw and classify zones as per above mentioned standards for each block (on GA drawing)
  • To Verify electrical equipment for their fitness (Protection, cabling and Temperature class) for particular zones obtained after the study and to suggest protection and type for the (yet to be procured) electrical equipment to be installed in the Hazardous area as per zones classified.
  • To submit the drawings (updated with HAC zones) and equipment selection criteria containing the observations and recommendations.
  • To calculate CFM values for ventilation requirements for related process areas under zones.

Coverage in Study

  • Area Classification & Zoning (Class & Zone (0, 1, 2 for gases & 20, 21, 22 for dust hazard) as per the chemical list, pipeline drawing, process flow diagram etc.
  • GA drawing shall be updated as per the zones and class.
  • Selection & installation of electrical Equipment & Cables
  • Temperature Class criteria for Electrical equipment
  • Selection criteria according to the Auto Ignition Temperatures
  • Symbols Standardization
  • Type of protection and degree of protection
  • Indian Standard Marking Scheme
  • Maintenance guidelines for the equipment as per Standard requirements.