A Better Understanding of NFPA 70E: Part IV – Two Types of Exposure to Electricity Fatalities
There are two ways to contact energized electrical parts or equipment, according to the Bureau of Labor Statistics (BLS) database, and those are direct or indirect. Direct exposure to electricity includes contact directly from the power source to the person, such as touching a live wire or getting caught up in an arc-flash. Indirect exposure typically occurs when an object is unintentionally electrified. Indirect exposure to electricity includes when a ladder being carried contacts a power line, when contact is made to an enclosure that is energized, or when electricity is transmitted through a wet surface. Exposure to electricity has been associated with 1,653 fatalities since 2011, according to the BLS. Of those fatalities, 858 were reported to be due to direct contact while 688 were reported as due to indirect contact. The following chart shows the total fatalities associated with each type as well as the voltage associated with those fatalities since 2011. SOURCE: BLS It may seem odd that the number of fatalities for greater than 220 volts is the same for both contact types. However, you may remember from reading last month’s blog that powerlines and transformers account for over half of all electrical fatalities. Many of those fatalities are attributed to contact through a conductive component, such as a ladder, boom truck, or dump trunk. It is probable that these account for many of the indirect exposures above 220 volts. Perhaps employers should evaluate how their electrical safety program addresses risks and tasks when any employee is around a powerline. RELATED: Download the Key Components of an Electrical Safety Program fact sheet The direct exposure fatalities for both voltage ranges are troubling since employers are required by Federal Law and NFPA 70E®, Standard for Electrical Safety in the Workplace®, to protect employees from known electrical hazards. Electric shock has been recognized as a hazard for over 100 years and arc-flash has been for over 40 years. It is uncommon to have electrical hazards exposed during normal operation of equipment or with equipment that is properly maintained. Making direct contact with an exposed, energized part typically occurs when an employee is knowingly exposed to an industry recognized electrical hazard. Direct exposure fatalities below 220 volts could be due to the perception that household voltages are not as dangerous as over 220 volts and, therefore, an ESWC is not necessary. Lower voltage fatalities could be due to complacency since these voltages are commonly encountered. An employee performing a task near a powerline is as knowingly exposed to a hazard as an employee performing energized work in a panelboard. Whether it is justified or not, the exposure could be due to an assigned task. It could be due to an employee not being trained to recognize electrical hazards for the task assigned to them. It could be due to exposed hazards in equipment that has not been properly maintained. If your electrical safety program does not address what is required by NFPA 70E, every employee could be routinely exposed to electrical hazards since nothing is being done to ensure that they are not. Fatalities due to indirect exposure to 220 volts and less are substantially fewer than for direct exposure. A lot of equipment in this voltage range is consumer type products. Manufacturers of this equipment often use product standards to evaluate the equipment for safety. These products typically undergo third-party listing due to the risk associated with the consumer use. Often, there are no exposed conductors or parts to make indirect contact with at these lower voltages, which are commonly referred to as household voltages. Although, it is often assumed that direct contact is the focus of NFPA 70E, both contact methods are addressed. Proper application of the conditions of normal operation, approach boundaries, and Section 130.8 could decrease the number of indirect contact fatalities. Establishing an electrically safe work condition, justifying energized work, and using personal protective equipment could decrease the number of direct contact fatalities. Make sure your electrical safety program addresses preventing all possible exposures to electricity from any piece of electrical equipment wherever your employee works.