Like clockwork, every three years, the National Fire Protection Association (NFPA) updates the Standard for Electrical Safety in the Workplace (NFPA 70E). The most recent revision occurred in 2015, and it clearly focused on amping up several areas of arc flash requirements. The new 2018 version on the horizon appears to be similar in emphasis, too.
Alongside the 2015 NFPA 70E, in 2014, OSHA also made updates to the Electric Power Generation, Transmission, and Distribution Standard (29 CFR 1910.269), which addressed the arc flash hazards in the applicable industries covered by this regulation. Similar to the 70E, the OSHA updates to 1910.269 included changes to several areas, such as training, estimations of arc flash energy, minimum approach distances, and personal protective equipment.
Each of these areas are intended to prevent catastrophic, and potentially lethal, arc flash and electrical injuries in the workplace. Due to the severity of arc flash incidents, stringent methods are needed to protect workers.
To that end, proper selection of PPE is critical. Arc flash is an unforgiving event if it transpires. Even PPE may not fully protect workers in the event of a serious electrical event, but the wrong selection can be deadly.
We’ll learn more about all that in this article.
Arc flash is a far-reaching threat, as virtually anyone who works on or in proximity to live electrical equipment can have exposure to the hazard, as illustrated by this sample from our online arc flash training course.
In the manufacturing industry, it’s often maintenance workers who are repairing equipment or performing live testing that are at greatest risk for arc flash events.
Construction industries, as well as utility workers, also have high rates of electrical injuries.
However, if the right conditions occur, any employee can have exposure. For employers, this means you must know the proper selection of PPE, as well as ensure that your workers are trained in electrical safety.
Like many employers, you may be wondering, “Do my employees need an arc flash suit?” Or maybe “What kind of electrically-rated gloves do I buy?” These are not questions with short, simple answers. And you’ll need to do your homework to understand the steps involved.
Prior to selecting PPE, employers must conduct an arc flash risk assessment, which determines arc flash hazards of any energized equipment. If there are indeed arc flash hazards present, incident energy is calculated, arc flash boundaries are determined, equipment is appropriately labeled, safe work practices are created and the corresponding PPE is selected. (Training is further developed from each of these areas.)
In the 2015 NFPA 70E, there are two methods to determine the necessary PPE for various job tasks.
Each of the above uses similar electrical data (such as fault-clearing time and available short-circuit current) to determine the hazard level of the arc flash. Either method can be used, if applicable, as the NFPA does not have a preference. You are permitted to use both methods in the same workplace. However, you must choose only one method per piece of equipment.
The Flash PPE Category Method looks attractive to most employers. Thanks to revisions in the 2015 70E, this is a more straightforward process than it used to be. The current 70E now uses a series of NFPA-developed tables which you consult to determine PPE and approach boundaries.
Essentially, you begin with the first table, (Task Table). There you find a list of tasks, such as, “For AC systems: Work on energized electrical conductors and circuit parts, including voltage testing.” By consulting the table, you will see the various tasks which require arc flash PPE. The answers are given in a straightforward, “yes/no” format. The table will also guide you through the condition of the equipment, as that factors into the need for arc flash PPE, as well. Both AC and DC tasks are listed on the table.
Then, if arc flash hazards exist, you move to the second step—the Equipment-based Table. And if your equipment is listed here, with designated parameters, you will find the applicable arc flash PPE category, as well as the arc flash boundary.
Following this step, you will consult the final table, the newly modified Protective Clothing and Personal Protective Equipment Table 130.7(C)(16). This table lists required PPE for that category. All of the listed PPE and clothing must be worn by workers.
But…wait. It’s not that simple. Using the table method has limitations. If the equipment is not listed on the table or if even one parameter is exceeded, this method cannot be used. Any variations (such as working distance) negates the use of the table method. Also, this method requires accurate knowledge of the equipment, including bolted fault current supplied, impedence and clearing time. If you don’t know these with certainty, you should not use this approach.
Sometimes, the only way to make proper PPE selection is through the more complex Incident Energy Analysis Method. This is an analysis that often requires external consulting services, or dedicated software to perform the detailed calculations. It can be costly and time-consuming, but it is more accurate. Even if you have resources to perform this in-house with software, it is often best to double-check those results with an electrical engineering firm to ensure accuracy.
There are four PPE levels (1-4) listed by the 2015 NFPA 70E, each of which is meant to correspond with the amount of incident energy it can withstand due to an arc flash. (Incident energy is measured in unit calories per square centimeter (cal/cm2).) Note: PPE levels are now called, “Flash PPE Categories.” If you have purchased arc flash PPE previously, you will remember these used to be called “Hazard Risk Categories.”
PPE garment manufacturers list the appropriate Flash PPE category, as well as the Arc Flash Thermal Performance Value (ATPV) for their products. The ASTM International defines as the maximum incident heat energy that a fabric can absorb and reduce the injury to a second degree burn. The ATPV is denoted on PPE in calories per square centimeter (cal/cm2), as it corresponds with incident energy.
You must match PPE to the Flash PPE Category, or go up a level if necessary. However, excessive PPE can be bulky and detrimental to the employee’s safety in other ways. Therefore, really explore options, either through eliminating the workplace task or evaluating several types of PPE that meets the arc flash hazard requirements.
It is vital to obtain the appropriate arc safety eye and face protection. Regular safety glasses are not protective against energized equipment, and may contain exposed metal parts that can conduct current. Additionally, dangerous and blinding energy wavelengths are released during an arc flash, which necessitate specific lenses to absorb the impacts to the eye.
Face shields or hoods, which cover the entire forehead, ears, and neck are necessary to prevent or minimize concussions and injuries sustained from molten metal and flying debris.
Below are the categories and required PPE. Remember, employees must wear all the required clothing and PPE listed for the designated category. Additionally, the new PPE category table no longer references a category 0, as previous editions had.
|PPE Category||Clothing Description||Minimum ATPV Rating (Cal/cm2)||Required Garments||Required Protective Equipment|
|1||Arc-rated clothing (see note 1)||4||Shirt (long sleeve) and pants (long) or coverall; Flash suit hood or faceshield (see note 2); Jacket, parka, rainwear, or hardhat liner (AN)||Hard hat; Safety glasses or goggles (SR); Hearing protection (ear canal inserts); Heavy-duty leather gloves (see note 3); Leather footwear (AN)|
|2||Arc-rated clothing (see note 1)||8||Shirt (long sleeve) and pants (long) or coverall; Flash suit hood or faceshield (see note 2) and balaclava; Jacket, parka, rainwear, or hardhat liner (AN)||Hard hat; Safety glasses or goggles (SR); Hearing protection (ear canal inserts); Heavy-duty leather gloves (see note 3); Leather footwear|
|3||Arc-rated clothing system (see note 1)||25||Shirt (long sleeve) (AR); Pants (long) (AR); Coverall (AR); Flash suit jacket (AR); Flash suit pants (AR); Flash suit hood; Gloves (see note 1); Jacket, parka, rainwear, or hard hat liner (AN)||Hard hat; Safety glasses or safety goggles (SR); Hearing protection (ear canal inserts); Leather footwear|
|4||Arc-rated clothing system (see note 3)||40||Shirt (long sleeve) (AR); Pants (long) (AR); Coverall (AR); Flash suit jacket (AR); Flash suit pants (AR); Flash suit hood; Gloves (see note 1); Jacket, parka, rainwear, or hard hat liner (AN)||Hard hat; Safety glasses or safety goggles (SR); Hearing protection (ear canal inserts); Leather footwear|
KEY: AN = as needed (optional); AR = as required; SR = selection required
*One of the two basic methods is used to determine a HRC for a job task
Notes: (1) Arc rating is defined in article 100.
(2) Faceshields are to have wrap-around guarding to protect not only the face but also the forehead, ears and neck, or, alternatively, an arc-rated arc flash suit hood is required to be worn.
(3) If rubber insulating gloves with leather protectors are used, additional leather or arc-rated gloves are not required. The combination of rubber insulating gloves with leather protectors satisfies the arc flash protection requirement.
You may wonder why hearing protection is listed in the NFPA PPE categories above. Hearing protection is required, as the sound from an arc flash blast can be equal to a jet engine, and may rupture ear drums.
And finally, the best step is prevention.
Even the most elite PPE may not protect workers from flying shrapnel, molten metal or arc blast pressure waves that can cause serious injuries. Poorly maintained equipment, corrosion, dust—even normal wear and tear, can result in an arc flash. Comprehensive electrical safety training, and a good preventative maintenance program can help reduce the risks of these potentially deadly events.
Convergence has several premium training options related to this topic. Our online Arch Flash Safety training course introduces the dangers of arc flash and presents common methods for preventing and protecting against those hazards. This is an ideal course for all workers.
Our online NFPA 70E training course covers important safety guidelines, including safety boundaries around electrical equipment, and PPE requirements. It is a must for your maintenance workers, safety committee, and management.
To help employees understand fundamental electrical concepts and safe electrical work practices, choose Protective Measures and Devices. Any, or all of these, should be part of the training you offer. Remember, prevention is key in electrical safety.
We hope this article helped to answer some of your questions about personal protective equipment (PPE) for arc flash protection. Let us know if you have any other questions.
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