Session No. 695

NFPA 70E: Choosing the Right Personal Protective Equipment (PPE) Wesley J. Maertz, CSP Technical Product Support W.W. Grainger, Inc. Janesville, WI

Introduction This is a discussion about selection of appropriate personal protective equipment (PPE) when working in a live electrical environment for decision makers. It is designed to clear up the confusion centered around the two methods presented in the 2012 edition of NFPA 70E and define the logic behind using each method. It is often said that OSHA is the “shall” and NFPA 70E is the “how” as it relates to working in a live electrical environment and PPE selection. OSHA tells us, under 29 CFR 1910.335(a)(1)(i), which requires the use of appropriate protective equipment when working where a potential electrical hazard exists, and 29 CFR 1910.132(d)(1), which requires the employer assess the workplace for hazards and the need for personal protective equipment (OSHA 1990, 1994). NFPA 70E is the tool employers can use to meet these OSHA requirements. It will help develop and document an overall electrical safety program that directs activity appropriate for electrical hazards, voltage, energy level, and circuit conditions. One major element of an electrical safety program is a hazard identification and risk assessment to determine protective equipment needs, including PPE. This risk assessment must be done before any work is started within a shock or arc flash boundary. The design of a safe electrical work environment begins with procedures to effectively eliminate lockout/tagout (LO/TO) or engineer out all possible electrical hazards. If that is not feasible, then protecting employees with appropriate PPE is critical. An arc flash analysis is the cornerstone of all risk assessments in determining appropriate PPE in a live electrical environment. Understanding each arc flash analysis method and the differences can make a stressful task much less stressful. Remember, that ignorance of these regulations will not work in a court of law as a defense of an OSHA citation stemming from an electrical incident.

Need for NFPA 70E-2012 As we discussed above OSHA requires employers to select appropriate PPE, and the reason to wear PPE in live electrical situations is to prevent thermal burns resulting from an electrical arc event. Burns are the leading injury type resulting from electrical arc events. According to the National Safety Council (NSC), the overall average cost per medically consulted injury was $37,000 per case (NFPA 2913, 62). This includes estimates of wage losses, medical expenses, administrative expenses, and employer costs; it excludes property damage costs except to motor vehicles. When you separate medical injuries associated with burns even low-intensity treated per case cost may jump to $206,853 (Paradigm 2013). For severe burns, the average per-case costs jumps to about 1.6 million, and when you add in additional complications that may be incurred, a severe burn can cost more than 10 million to treat successfully (Paradigm 2013). Using NFPA 70E to select appropriate PPE is vital to reduce the potential costs incurred as result of a burn. Exhibit 1 shows since 1992 fatal electrical injuries have declined by more than 50% on an annual basis and this has accelerated in the last five years (ESFi 2012). Nonfatal electrical injuries have shown an even more dramatic improvement in this same time span. In 2010 nonfatal electrical injuries are down by more 60% (ESFi 2012). According to the Electrical Safety Foundation International (ESFi), they have identified two reasons for this downward trend of electrical fatalities/injuries (ESFi 2012), 1. Sharper declines over the last few years were probably due to the recent slow-down in the economy. 2. The advancement of NFPA 70E as an important electrical safety standard is surely a component. Real improvement in electrical safety can be sustained through the increased use of techniques and methods found in 70E and through training targeted at people in high-risk occupations and industries. Electrical safety is an area where perseverance pays off.

Exhibit 1: Total Number of Electrical Fatalities per Year, 1992-2010 (Source: ESFi 2012)

Summary of NFPA 70E-2012 As we have seen, both OSHA and NFPA have written standards and regulations that build on one another and help keep all workers safer from electrical hazards in the workplace. It is important to note that the NFPA 70E is a national consensus safety standard published by the National Fire Protection Association (NFPA) primarily to assist OSHA is preparing electrical safety standards. Federal OSHA has not incorporated past or current editions of NFPA 70E into the Code of Federal Regulations (CFR). This commonly leads to the question, “Is compliance with NFPA 70E mandatory?” The answer to that question is NO. Remember, NFPA 70E is a national consensus safety standard that is not incorporated into the CFR. This means OSHA cannot enforce this rule in the workplace if the workplace is under OSHA jurisdiction. So you may be wondering why NFPA 70E exists if it is not required or enforceable by OSHA. This can be understood by the answer to the question “Can I be cited for not complying with NFPA 70E?” The answer to that question is YES by using NFPA 70E as evidence to cite under Subpart S electrical standards. The employer must assess the workplace for electrical hazards and the need for PPE under Subpart S, such as 29 CFR 1910.335(a)(1)(i) (OSHA 1990). Details on how to comply with this standard are left up to the employer. The employer is expected to use the best means available to comply with this requirement, and that is done through consensus standard NFPA 70E. Compliance with 70E will assure compliance with OSHA Subpart S requirements. In the event of an injury or death due to an electrical incident, if OSHA determines in a court of law that compliance with NFPA 70E would have prevented or lessened the injury, OSHA can cite under Subpart S, using NFPA 70E as evidence. In a standards interpretation letter dated 11/14/2006, OSHA stated that the NFPA 70E electrical safety standard can be used as evidence of whether the employer acted reasonably (OSHA 2006). NFPA cautions that PPE selected based on an arc flash analysis is intended to protect a person from arc flash and shock hazards and resulting burns but does not address protection against physical trauma resulting from an arc explosion as shown in Exhibit 2.

Exhibit 2: Anatomy of an Electrical Arc (Source: NFPA 2012)

The goal of wearing appropriate PPE is to prevent the onset of a second-degree burn on the surface of the skin. NFPA has determined that an energy level greater than 1.2 calories per square centimeter, about the surface area on the tip of your finger, is the amount of energy necessary to result in a second-degree burn. An arc flash analysis determines the energy produced due to an arc and amount of PPE necessary inside this flash boundary. See Exhibit 3.

Exhibit 3: Flash Protection Boundary (Source: NFPA 2012) NFPA 70E, paragraph 130.7(C), addresses sixteen criteria associated with use of PPE each employer should address before using selected PPE (NFPA 2012). See Exhibit 4.

1. 2. 3. 4. 5. 6. 7.

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General Critera Movement and Visibility Head, Face, Neck and Chin Protection Eye Protection Hearing Protection Body Protection Hand & Arm Protection • Shock Protection • Arc Flash Protection • Maintenance & Use 8. Foot Protection 9. Factors in Selection of Protective Clothing • Layering – Annex M • Outer Layers • Under Layers

Head Protection o Balaclava o Hood • Face Protection • Hand Protection o Leather or arc-rated gloves o Insulating gloves • Foot Protection 11. Clothing Material Characteristics 12. Clothing and other Apparel Not Permitted 13. Care and Maintenance of Arc-Rated Clothing • Inspection

• Coverage • Fit • Interference 10. c Flash Protective Equipment

14. Standard for PPE 15. Selection of PPE when required for Tasks • Table 130.7(C)(15)(a) AC current • Table 130.7(C)(15)(b) DC current 16. Selection of all PPE based on hazard Category

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Suits

• • •

Manufacture Instructions Storage Cleaning, repairing, and affixing items

Figure 4: Personal and Other Protective Equipment Criteria (Source: NFPA 2012)

Arc Flash Analysis Methods As we discussed earlier, OSHA requires the employer to do a risk assessment to determine electrical incident potential for each piece of electrical equipment in the facility. We also learned that an arc flash hazard analysis is the tool used to complete the risk assessment. An arc flash analysis accomplishes three main goals: 1. 2. 3.

Determine the arc flash boundary incident energy at the working distance Determine the personal protective equipment (PPE) necessary if inside the flash boundary Determine necessary information needed for equipment labeling

Two arc flash analysis methods are presented in NFPA 70E, paragraph 130.5(B), that meets the second goal of PPE selection (NFPA 2012): 1. 2.

Incident Energy Anaylsis Hazard/Risk Category Tables

Both methods determine the level of hazard related to the arc flash, based on a few variables: the available bolted fault current supplied from the source, the clearing time (time at which a breaker opens or fuse blows), and impedance between the point of the flash and the source. Both

methods account for these variables and determine the incident energy potential of each piece of electrical distribution equipment in the facility, but each will do it in a different capacity.

Hazard/Risk Category Tables It is important to note that selection of equipment using this method was based on the collective experience of a task group and ESTIMATED exposure levels. Additonally, the tables have use limitations as stated in the body of the table. See Exhibit 5. They specify a range of available fault current and clearing times for the upstream over-current protective device. This method may not be safely used beyond these limitations and ranges listed. This can commonly lead to misuse of the table method, which can lead to over-protection or under-protection for the worker. If the task being assessed does not fit the task described or use limitations then an incident energy analysis must be done. This method presents a fast and convenient way to determine appropriate PPE. NFPA intended to present a “collective” thought of common tasks that are performed and present it in an easy-to-read table to quickly assess PPE needs, however, the user must have a sound understanding of all the variables involved and job task involved so all limitations are met.

Exhibit 5: Example of Hazard/Risk Category Table (Source: NFPA 2012)

Incident Energy Analysis This method is much more time consuming and costly but provides a complete evaluation of the power system with the actual incident energies (calories) on each piece of equipment clearly defined. There are three basic ways to complete the incident energy analysis: 1. Hire an expert 2. Complete calculations according to Annex D of NFPA 70E

3. Use software or online calculator to complete calculations As we discussed above, three goals must be met to complete a proper risk assessment of your facility and to accomplish all three main goals: deteriming arc flash boudary, PPE, and labeling of equipment, an incident energy analysis is necessary to accomplish all three of these goals.

Conclusion Utilizing the proper PPE when working in live electrical environments is a critical component to an electrical safe work program (ESWP). Understanding how to properly assess the risk of electrical hazards is vital in determining the appropriate PPE for the job being performed. Understanding the differences between both arc flash analysis methods and when to use each in the appropriate situation will mitigate risk, liability, and cost related to an electrical incident in the workplace. Some parting thoughts to consider when performing a risk assessment for PPE in live electrical environments: • • •

Do you really know the bolted fault current supplied for the equipment? Do you really know the clearing time for the equipment? Do you really know the impedence for the equipment?

Can you answer yes to each above with confidence? Are you confident in your PPE decision based on sound practices to put your worker in harm’s way, or did you make assumptions to get the job done quickly and cheaply? If an electrical incident happens in your facility, are you prepared to show beyond reason of doubt why you chose the PPE level for the job?

Bibliography Paradigm Management Services. 2013. “Treatment Costs of Severe Burn Injuries.” (Retrieved February 25, 2014) (http://www.paradigmcorp.com/blog/?p=799) National Safety Council (NSC). 2013. Injury Facts. Itasca IL: NSC. Electrical Safety Foundation International (ESFi). 2012. “Electrical Safety Then & Now: 20 Years of Electrical Injury Data Shows Substantial Electrical Improvement.” (retrieved March 17, 2014) (http://www.esfi.org/index/cfm/FAP/cdid/12394/pid/10272) National Fire Protection Association (NFPA). 2012. NFPA 70E, Standard for Electrical Safety in the Workplace. Quincy, MA: NFPA. Occupational Safety & Health Administration (OSHA). 2006. Interpretation Letter (retrieved February 21, 2014) (https://www.osha.gov/pls/oshaweb/owadisp.show_document?p_table=INTERPRETATI ONS&p_id=25557)

______. 1994 29 CFR 1910.132(d)(1), Personal Protective Equipment General Requirments (retrieved February 21, 2014) (https://www.osha.gov/pls/oshaweb/owadisp.show_document?p_table=STANDARDS&p _id=9777) ______. 1990 29 CFR 1910.335, Safegards for Personnel Protection (retrieved February 21, 2014) (https://www.osha.gov/pls/oshaweb/owadisp.show_document?p_table=STANDARDS&p _id=9912)