Electrical Safety on Construction Sites

About this course.

Electricity is a major construction hazard because it can kill or seriously injure instantly, often without warning and without any visible sign that a conductor is live. The three main ways it causes harm are electric shock, which can stop the heart or cause severe burns; arc flash and arc blast, which release intense heat, light and pressure; and electrical fire. Construction sites make these risks worse because installations are temporary, conditions are wet and rough, equipment is heavily used and damaged, and work happens near live powerlines and buried cables. Under the model Work Health and Safety (WHS) framework, everyone on site carries duties to manage these risks so far as is reasonably practicable.

Electric shock is the most familiar hazard and the one that most often kills. When a person becomes part of an electrical circuit, current flows through the body, and even a relatively small current can be dangerous depending on its path, duration and the conditions. Current passing through the chest can disrupt the heart's rhythm and cause cardiac arrest; current can also cause muscles to contract so strongly that a person cannot let go of the conductor they are gripping, prolonging the contact and the injury. Electric shock can also cause deep internal and external burns where current enters and exits the body, falls from height triggered by an involuntary reaction, and other secondary injuries. Wet skin, sweat and damp conditions lower the body's resistance and increase the danger, which is one reason construction sites — frequently wet, muddy and exposed to weather — are such high-risk environments.