Hazardous Area Risk Assessment — Electrical Guide

The Dangerous Substances and Explosive Atmospheres Regulations 2002 (DSEAR) require employers to carry out a risk assessment of any workplace where dangerous substances are present that could create an explosive atmosphere. This risk assessment forms the basis for zone classification, equipment selection, and the competency requirements for workers.

What a DSEAR Risk Assessment Must Cover

• Dangerous substances present — identification of all flammable liquids, gases, vapours, mists, and combustible dusts
• Quantities and conditions — under what conditions can an explosive atmosphere form
• Ignition sources — identification of potential ignition sources including electrical equipment
• Zone classification — extent of Zone 0, 1, 2 (gas) and Zone 20, 21, 22 (dust) areas
• Equipment assessment — verification that existing electrical equipment is appropriate for its location
• Worker competency — confirmation that workers performing hazardous area electrical work are competent (CompEx)

Zone Classification Documents

The risk assessment produces zone classification drawings — typically a set of site plans showing the boundary and type of each hazardous zone. These drawings are the reference document for all equipment selection and installation decisions. They must be kept current and reviewed whenever plant layout or processes change.

Competency Requirements

DSEAR explicitly requires that persons carrying out work involving dangerous substances are competent to do so. For electrical work in hazardous areas, CompEx certification is the accepted standard for demonstrating this competency in the UK oil and gas, petrochemical, and process industries.