With the recent changes to the OSHA standard, many employers are working on what rules apply – the arc flash standard or the PPE standard – and how to comply with them. Part of the issue is determining how many types of protection are needed and what types of protection are appropriate.
To begin, OSHA’s requirements for all personal protective equipment can be found in 29 CFR 1910 Subpart I. Rules specific to hand protection can be found in 1910.138. They read as follows:
“General requirements. Employers shall select and require employees to use appropriate hand protection when employees' hands are exposed to hazards such as those from skin absorption of harmful substances; severe cuts or lacerations; severe abrasions; punctures; chemical burns; thermal burns; and harmful temperature extremes.”
“Selection. Employers shall base the selection of the appropriate hand protection on an evaluation of the performance characteristics of the hand protection relative to the task(s) to be performed, conditions present, duration of use, and the hazards and potential hazards identified.”
Protecting workers’ hands is critical because, when incidents occur – particularly incidents that involve arc flashes – hands are subject to be the most severely injured body parts. In the time it takes for a device to clear a fault, or for the material to burn completely and extinguish the arc, hands can be exposed to temperatures from 500 to 10,000 degrees Fahrenheit depending on the fault current and clearing time. To give you a point of reference, skin can be subject to a first-degree burn if it is exposed to a temperature of 110 degrees Fahrenheit for 1 second, 60 cycles.
So, how are determinations made as to when and what type of hand protection shall be worn? A properly performed hazard analysis should be used to identify the protective equipment that will mitigate risks and control hazards. Per 1910.132(d)(2), OSHA requires employers to identify hazards through a written PPE certification. The full text of 1910.132(d)(2) states, “The employer shall verify that the required workplace hazard assessment has been performed through a written certification that identifies the workplace evaluated; the person certifying that the evaluation has been performed; the date(s) of the hazard assessment; and, which identifies the document as a certification of hazard assessment.”
Typical Hand Injuries
Cuts, lacerations and punctures are the most common hand injuries sustained by electrical workers. Other typical hand injuries include friction burns, pinches, and broken bones caused by falls or being struck by an object. If you’re interested in learning more about injury types and frequency of occurrence, the U.S. Bureau of Labor Statistics provides that information and breaks it down by industry.
With the proper use and application of protective gloves – for example, cut-resistant work gloves – hand and skin injuries can be decreased in number or avoided altogether. Severe pinches and cuts often occur when an employee does not wear work gloves while performing a task that requires them. Just the simple act of wearing leather gloves will decrease the severity of many accidents involving strikes, caught-betweens, pinches and burns.
As of the 2014 update, OSHA’s 1910.269 standard requires all body parts to be protected by arc-rated FR clothing with several exceptions: the head, as long as the employee is wearing a Class E hard hat; the hands, when the employee is wearing properly rated rubber gloves with heavy leather protectors; and the feet, when the employee is wearing heavy leather boots or shoes. Burn injuries can easily be prevented or their severity limited when employees wear properly rated FR clothing and gloves. When an arc flash occurs and appropriate garments aren’t being worn, the worker’s hands and face usually sustain the worst injuries. This is because they are typically closest to the fire and, more often than not, the worker’s hands trigger the event.
There is no accepted and recognized arc thermal performance value (ATPV) for rubber gloves and sleeves, but they are electrically tested and have been proven to sustain significantly high calorie arcs without breakdown or breakthrough of the material. Tests have confirmed that as much as 40-cal/cm2 protection can be provided by Class 2 rubber gloves and sleeves with nominal heat transfer to skin. The arc-rated FR clothing under rubber sleeves provides additional thermal protection from heat transfer. Although OSHA does not recognize ATPVs of gloves or sleeves, hopefully that will change someday soon.
In Addition to Hands
As I mentioned earlier, arc-rated FR clothing is now required per OSHA rule 1910.269(g), “Personal protective equipment.” In 1910.269(l)(8)(iv), OSHA states that employees must wear arc-rated FR clothing under any of the following four conditions:
1. When the employee is exposed to contact with energized circuit parts operating at more than 600 volts.
2. When an electric arc could ignite flammable material in the work area that, in turn, could ignite the employee's clothing.
3. When molten metal or electric arcs from faulted conductors in the work area could ignite the employee's clothing. This does not apply to conductors that are capable of carrying, without failure, the maximum available fault current for the time the circuit protective devices take to interrupt the fault.
4. When the incident heat energy estimated under paragraph 1910.269(l)(8)(ii) exceeds 2.0 cal/cm2.
Arc-rated FR clothing must be furnished by employers at no cost to employees when the employees may be exposed to arcs or flames. Properly rated FR clothing provides protection for the employee from electrical arcs that will break open and ignite work clothes made of 100 percent cotton. There is very little insulation protection from heat transfer in an arc. The arc can be 10,000 degrees Fahrenheit or greater depending on the fault type and duration. The arc-rated inhibited value of the clothing will prevent it from breaking open, and the ASTM F1506 FR treatment ensures the material will self-extinguish in about 10 seconds or fewer if the clothing is exposed to an arc with heat energy greater than the clothing is rated for.
Another new requirement found in the 2014 update to 1910.269 is that employers must identify locations where incident heat energy will exceed the 8-cal/cm2 single-phase open air arc. The employer has to make a reasonable estimate using an industry-accepted method of calculating the incident energy available at work locations. If exposure is less than 8 cal/cm2, ANSI Z87.1+ safety glasses, or safety goggles worn over prescription lenses, are required. If exposure is greater than 8 cal/cm2, employers must ensure an employee’s face is protected with at least an 8-calorie arc-rated face shield. If the arc energy exposure is greater than a 13-calorie single-phase open air arc, a balaclava and a flash suit must be used. A rated face shield is required for any multiphase arc exposures greater than 5 calories.
About the Author: Danny Raines, CUSP, safety consultant, distribution and transmission, retired from Georgia Power after 40 years of service and opened Raines Utility Safety Solutions LLC, providing compliance training, risk assessments and safety observation programs. He is also an affiliate instructor at Georgia Tech Research Center OSHA Outreach in Atlanta. For more information, visit www.electricutilitysafety.com.
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