Selection of Electrical Equipment for Hazardous Locations

These courses explain how facilities that handle or process flammable materials (powders, gases and vapors) are classified into divisions/zones and how those divisions/zones are used to specify electrical equipment in the facility. Courses are offered at 3 levels:

  • Introductory Level
  • Core Competence
  • Advanced

Here we illustrate a typical course at the Core Competency level. Sample course:

Who Should Attend

This course will benefit staff with an interest in process safety, EH&S, process design and operations including plant management, technical staff, supervisors and maintenance personnel. It is especially relevant to those who work in the chemical & processing industries, including bulk and finished pharmaceuticals, bulk and fine chemicals, food, plastics, metals, textiles, paper, lumber, agrochemicals, dyes and paints.

Learning Objectives

Upon completion of the course, the attendees will understand:

  • how fire and explosion hazards are caused by inappropriately selected electrical equipment
  • the requirements of the codes and standards for the classification of hazardous locations
  • the classifications of locations where combustible dust accumulations and clouds and flammable gases/vapors atmospheres can be present
  • How electrical equipment is selected for use in hazardous locations

Course Outline


  • Introduction to Fire and Explosion Hazards
  • Applicable Codes, Standards, and Guidelines
  • Flammability Characteristics relevant to electrical area classification
    • Gas Groups (A, B, C, D), Flashpoint, flammable range, autoignition temperature, ignition sensitivity, vapor density
    • Dust groups (E, F, G), Minimum Explosible Concentration, minimum ignition temperature (cloud & layer)

Classification of Hazardous Locations

  • Identification of Hazardous Locations
  • Determination of the Extent of Locations Containing Flammable Gases and Vapors
  • Determination of the Extent of Locations Containing Combustible Dusts
  • Factors Affecting the Extent of Hazardous Locations – Ventilation, Temperature, and Pressure

Selection of Electrical Equipment for Hazardous Locations

  • Summary of common methods for protection in Different Classes and Divisions
  • Ingress Protection
  • Intrinsic Safety


Course Description

Incorrectly specified electrical equipment can be a source of ignition of flammable atmospheres.  The objective of hazardous (electrical) area classification is to identify the likelihood of presence of flammable gas, vapor, and/or dust cloud atmospheres, and/or dust accumulations in a facility and reduce the risk of ignition by the specification and installation of suitable electrical apparatus.  This course will provide a basic understanding of the science behind fire and explosion hazards and how electrical equipment can provide a potential source of ignition. It examines how standards are used to control ignition risk through classification of hazardous areas into zones and then how correct specification of electrical equipment is determined in those classified zones. Discussion sessions allow course participants to clarify their knowledge and consolidate their understanding. Why Work With Stonehouse Process Safety

We also offer virtual process safety training courses such as Exploding dusts, Explosions, Static Electricity and HAC (Hazardous Area Classification).  Find out more here.

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