what is an arc flash risk assessment, and what does it involve?

Prediction is about understanding what could happen before anyone opens a panel or touches a conductor. Using recognised calculation methods, the assessment estimates how much thermal energy could be released if an arc flash occurred at a specific point, and how far that energy could travel.

For you, this turns abstract electrical data into something practical. It tells you which locations carry higher exposure, what the arc flash boundaries are, and which jobs fall into a higher arc flash hazard risk category. That information becomes the basis for labelling equipment and planning work, so your team knows what they are walking into before they start.

Once the potential severity is known, the next step is to reduce the risk at source wherever possible. The safest arc flash is the one that never happens.

This stage looks at how work is carried out and whether live exposure can be avoided altogether. Isolating and proving equipment dead, improving maintenance, shortening fault-clearing times, or using equipment designed to contain or redirect energy all reduce the likelihood or impact of an event. Operational changes, such as using remote operation tools or alternative test methods, should also be considered.

The goal with prevention is to limit how often your team is exposed and reduce the energy they could be exposed to when live work cannot be avoided.

Many arc flash incidents happen during routine tasks carried out by experienced people. Things like switching, testing, or regular maintenance.

This part of the assessment looks at how tasks are controlled day to day. It covers who is allowed to carry out certain work, how jobs are authorised, and what checks must happen before work begins. Permit-to-work systems, clear isolation procedures, task-specific risk assessments and competency requirements are included here.

Controls that are well defined and followed help remove uncertainty on site. Because everyone knows what is expected, what is allowed, and when work should stop.

Even with strong controls in place, some risk remains. That’s where personal protective equipment comes in.

The assessment defines the level of thermal protection needed for each task, based on the predicted incident energy. This is used to select arc-rated clothing and accessories that limit burn injury if an arc flash occurs. In many cases, protection is built up through layers by combining base layers, mid-layers and outer garments to achieve the required rating without unnecessary bulk.

Protection needs to be complete. Clothing, face protection, gloves and other PPE must work together so no part of the body is left exposed. It also needs to be wearable. If PPE is too heavy, restrictive or uncomfortable, people are more likely to adjust it or avoid wearing it properly, which undermines the whole system.