Electric shock causes only about 20 per cent of all injuries among electrical workers. The majority of injuries in this profession are external burns or other effects of electrical arc explosions. There are between five and 10 reportable arc flash events every day in the country—averaging one fatality every 28 hours.
Arc Flashes: The Basics
The best way to think of an arc flash is as a short circuit through the air. An electric arc arises from energy being released through the air when high voltage exists across a gap between conductors. Any electrical service of more than 450 volts has the capacity for an arc flash, and they are especially dangerous because they are highly unpredictable. Arc flashes can not only give off thermal radiation and light that will scorch unprotected skin, but they could produce pressure and sound waves causing traumatic hearing loss or blunt force trauma from flying electrical components. Next to the laser, the electric arc is the hottest event on earth, with recorded temperatures as high as 19,426.7° C.
Arc flashes are often misunderstood because the worker will hardly ever come in contact with an energized electrical conductor when they occur. Also, arcing can occur with direct current like mine DC trolley systems or batteries. Therefore, the burns are not caused by electric shock, but rather by electromagnetic radiation that can vary from infrared to ultraviolet and cause anything from mild skin reddening to third-degree burns, including the complete destruction of skin, muscle and any other surrounding tissue.
There are several things that can cause an arc flash, including:
- Inadvertently bridging electrical contacts with a conducting object
- Dropping a tool or otherwise causing a spark
- Coming near an extremely high-amp source with a conducting object, causing the electricity to arc
- Breaks or gaps in insulation
- The buildup of dust or corrosion
- Equipment failure because of normal wear and tear or improper upkeep
Arc flash incidents are disproportionately fatal, and the hazards of electric arc flashes are present at many manufacturing workplaces. Also, the population of workers who could be exposed to arc flash dangers is on the rise. Injuries resulting from burns tend to cause more days off work—translating to more dollars for your company—than other types of work-related incidents. All of these reasons are incentive for you to introduce a risk management program for arc flashes.
The good news: in a study conducted recently, 94 per cent of arc flash victims or witnesses said the incident could have been prevented. The best thing you can do as an employer is educate yourself and your employees and place a high value on establishing a safe working environment so your workers will do the same.
What Actions Should Employers Take?
Employers must implement safe work practices to prevent electric shock or other injuries resulting from either direct or indirect electrical contacts, which would include arc flashes. Employers should be mindful of all national and provincial requirements when crafting workplace safety policies. In addition, the following recommendations are aimed to prevent arc flashing:
- All services to electrical equipment must be done in a de-energized state; that is, lockout and tag-out laws apply to all electrical work. Only two circumstances may be acceptable exceptions where working on live electrical parts would be permissible:
- When the work cannot be done on a de-energized system (only permissible if physically impossible, not acceptable if it is feasible but significantly more difficult on a de-energized system)
- When de-energizing equipment would create additional hazards (inconvenience does NOT qualify as an additional hazard)
- When performing work on an energized or live circuit, tools and equipment must be insulated.
- Personal protective equipment (PPE) must be worn for both eyes and face whenever the risk of arcing is present, and the use of protective shields or barriers are required where dangerous electric heating is present.
- PPE being used must fully protect employees from potential shock, pressure blasts and arc flash burn hazards based on the incident energy exposure and the specific task being performed.
What Does The Workplace Electrical Safety Standard Recommend?
In addition to these regulations, the Canada Standards Association (CSA) also recommends that employers follow the CSA Z462-08 Workplace Electrical Safety standard. CSA Z462 is based on the U.S. National Fire Protection Association (NFPA) standard NFPA 70E. CSA’s technical committee modified CSA Z462-08 in 2012 in order to technically harmonize with NFPA 70E as closely as possible for companies doing business in both Canada and the United States.
CSA Z462-08 gives step-by-step instructions on how to ensure a system is de-energized, how to label equipment properly, how to conduct a flash-hazard analysis and the type of personal protective equipment that should be used in a given situation. To clarify, CSA Z462-08 is not law. However, compliance with CSA Z462-08 may serve as evidence that a hazard prevention program is in place and save your company thousands of dollars in fines.
Who to Target with Arc Flash Safety Messages
As an employer, modelling safe job performance and enforcing safety precautions is crucial for all employees, regardless of experience. Because of their unpredictable nature and variety of causes, arc flash incidents could happen to anyone, no matter how qualified. In fact, let your employees know that the average arc flash victim is 37 years old with 16 years of electrical experience; this goes against the typical assumption that accidents only happen to young, inexperienced workers. It is also important to emphasize to your employees that arc flashes themselves are avoidable by being less careless and taking the necessary safety precautions.
As the employer, you are the model in the workplace. The more seriously you take safety, the more cautious your employees will be. This will result in fewer arc flash injuries and, in turn, fewer fatalities and ultimately lower workers compensation costs. If you have questions about how to model your safe job performance standards, or if you have additional questions about arc flash incident prevention, contact the Axis Insurance Group today.