Preventing arc flashes

Electricity can present many dangers for workers, including arc flash hazards. An arc flash occurs when high-amperage currents travel, or “arc,” through the air. This can happen when high-voltage differences exist across a gap between conductors. The result is an immediate release of tremendous amounts of energy that can reach temperatures as high as 36,000° F, according to the Washington State Department of Labor and Industries.

Consequences

Washington L&I states that the heat and light from an arc flash can melt clothing and destroy skin and tissue – and may even result in death. A victim also may fall and collide with objects as a result of being thrown by a pressure wave blast from an arc flash.

Additionally, Washington L&I points out that some workers may not be able to return to their pre-injury job, leaving employers to bear the costs associated with lost productivity and employee rehiring and retraining.

Prevention

To reduce the likelihood of arc flashes, Washington L&I advises employers to adhere to the “Hierarchy of Controls” by implementing the following safety protocols:

• Elimination/substitution – Schedule jobs when power sources can be de-energized, grounded and tested. Also, determine if a worn piece of electrical equipment can be removed from service or replaced with a newer model.
• Engineering controls – Implement barriers such as locked electrical vaults and high fences around dangerous locations.
• Administrative controls – Institute an effective lockout/tagout program that includes all necessary training and equipment.
• Work practice controls – Ask these questions: Does management set expectations for safe work practices? Do workers meet or exceed safety rules and best work practices? Do supervisors encourage following safety rules and enforce them?
• Personal protective equipment – Make sure employees are wearing proper protective clothing. For example, they should wear insulated gloves, fire-resistant clothing and a faceshield when working on energized electrical equipment.

Emergency response

If a worker suffers an arc flash injury, Washington L&I recommends the following:

• Rescue should be performed only by people trained in electrical hazards and rescue techniques.
• Do not touch the victim if he or she is in contact with an energized circuit. Shut off the power and contact emergency services. If you are unable to de-energize the circuit, dislodge the victim from the circuit using a non-conductive material.
• If the victim is on fire, smother or douse the flames. Remove smoldering clothing, but not clothing melted on the skin.
• If the victim is not breathing, provide CPR.
• Run cool – not cold – water over the burn area. Do not apply creams, ointments or ice. After the burn has cooled, cover it with a clean dry cloth.
• Always seek medical attention after an electrical shock or burn. A victim who feels fine may have internal injuries.