Several hazards hold the most potential for injuries
No matter how comfortable an electrician feels working with electricity, danger must never be overlooked. OSHA estimates about 350 electrical-related deaths occur each year. A shock as little as 1 mA can be dangerous and easily achieved at low voltage under certain conditions (wet surfaces, damaged or punctured skin).
Many injuries could be avoided with common sense and simple safety procedures. These hazards are the most frequent causes of electrical injuries.
Contact with power lines
Overhead and underground power lines are hazardous because they carry extremely high voltage. Electrocution is the main risk. However, burns and falls associated with a shock are common. Linemen are aware of these hazards and must adhere closely to safety regulations governing work on transmission and distribution lines. Others on typical construction sites should be aware of the location of power lines and avoid them whenever possible. Always assume power lines are energized unless specifically informed otherwise. Wherever possible, use nonconductive wood or fiberglass ladders when working near power lines.
Lack of ground-fault protection
Normal use of electrical equipment at job sites causes wear and tear that results in insulation breaks, short-circuits and exposed wires. The use of ground-fault circuit interrupters (GFCIs) can prevent potential injury created by these hazards. Employees should always follow the manufacturer’s recommended procedures and use double-insulated tools and equipment where appropriate. All equipment should be visually inspected before use. Any equipment with frayed cords, missing ground prongs or cracked tool casings should be tagged and removed from service immediately until the problem is repaired.
Path to ground missing or broken
Fault current can travel through a worker’s body, causing electrical burns or death if the power supply is not grounded or the path has been broken. Although the electrical system may be properly grounded, it also is necessary for all equipment to be grounded. By grounding all power supply systems, electrical circuits, and electrical equipment, and frequently inspecting electrical systems to ensure the path to ground is continuous, such hazards can be avoided.
Grounds should never be removed from any flexible or extension cords, and as always, grounds should be visually inspected before using the equipment.
A journeyman worker was electrocuted while working on metal ductwork, using a double-insulated drill connected to a drop light cord. Power was supplied through two extension cords from a nearby residence. The individual’s perspiration-soaked clothing/body contacted bare exposed conductors on one of the cords, causing an electrocution. There were no GFCIs in use at the time. Additionally, the ground prongs were missing from the two cords. This fatality could have been avoided by using the equipment properly and through inspection of the cords’ grounds.
Equipment used incorrectly
Any time electrical equipment is used in ways for which it is not designed, you cannot depend on manufacturers’ safety features. This may damage your equipment and cause employee injuries. A simple modification could lead to death. For example, an employee was using an air compressor with a plug and an extension cord modified to fit a wall outlet for a common household clothes dryer (220V). While trying to unplug the compressor, he was electrocuted. Had he used the equipment as it had been manufactured, his death might have been avoided.
Improper use of cords
The normal use and wear and tear can cause flexible and extension cords to no longer be properly insulated or grounded. Flexible cords and cables must be protected from damage. They cannot be hung around sharp corners or pass through doorways or other pinch points unprotected.
Changes in the insulation or wire can lead to serious injury. Employees must use extension cords that are the three-wire type and designed for hard or extra-hard use. Equipment should be unplugged by pulling on the plug, not the wire; pulling the wire compromises the cord’s safety. As always, all cords should be inspected for signs of wear or fraying.
Safety and health programs at the workplace should address electrical incidents and the variety of ways electricity becomes a hazard. In general, OSHA requires [29 CFR 1926.416(a)(1)] that employees not work near any part of an electrical power circuit unless properly protected. These hazards should be included in the continuing safety training of your employees. EC
O’CONNOR is with Intec, a safety consulting, training and publishing firm that offers on-site assistance and produces manuals, training videos and software for contractors. Based in Waverly, Pa., he can be reached at 607.624.7159 or firstname.lastname@example.org.