“You don’t know what you’ve got ’til it’s gone.” That famous song lyric can be appropriately applied to the 2015 edition of NFPA 70E. What is gone? Zero is no longer one of the hazard/risk categories (HRCs). In fact, HRCs also are gone and have been replaced with personal protective equipment (PPE) categories. And zero is missing from there, too. Zero traditionally meant that arc-rated protection was not required, but without zero, what do we do?


2012—zero


The 2000 edition of NFPA 70E introduced HRCs, and they remained through the 2012 edition. Listed as Table 130.7(C)(15)(a) and (15)(b) Hazard Risk Category Classifications, PPE requirements were ranked on a scale of 0–4 based on the equipment type and tasks to be performed. Several footnotes were also included to define limitations based on the maximum short-circuit current and arc-flash duration.


Once the HRC was determined for a given task and equipment, Table 130.7(C)(16) Protective Clothing and Personal Protective Equipment was used; this table listed the clothing and PPE requirements for each HRC. On the upper end of the scale, HRC 4 required a minimum arc rating of 40 calories per centimeter squared (cal/cm2). On the lower end, HRC 0 did not require any arc-rated clothing or arc-rated PPE, but clothing was required to be made of nonmelting or untreated natural fiber.


2015—no zero


A significant change was made to the 2015 edition of NFPA 70E. Table 130.7(C)(15)(A)(a) Arc Flash Hazard Identification was added, and it defines when arc flash PPE is required. This table also helps clarify what is meant by the term “interacting,” which was first introduced in the 2009 edition as part of the definition of an arc flash hazard.


The arc flash hazard could exist “if a person is interacting with the equipment in such a manner that could cause an electric arc.”


Since then, the use of “interacting” has continued to raise quite a few questions. Does operating a circuit breaker introduce an arc flash hazard? How about operating a disconnect switch? What sort of PPE is required for these types of tasks? Confusion could sometimes occur.


The new Arc Flash Hazard Identification Table contains a list of various tasks and can be used to determine if a specific task requires arc-rated PPE. Many of the tasks include five equipment conditions that must also be met, which helps clarify whether interacting with equipment requires arc-rated PPE.


Table 130.7(C)(15)(A)(a) lists “Normal operation of a circuit breaker” as not requiring arc flash PPE, as an example, but only if the equipment meets all of the following conditions:


• It is properly installed.


• It is properly maintained.


• It has closed and secured doors.


• It has covers in place and is secured.


• It has no evidence of impending failure.


If a task is not listed in the table, any of the five conditions are not met, or the table states that arc flash PPE is required, the minimum requirements can be determined by using Table 130.7(C)(15)(A)(b) and (15)(B) Arc Flash Hazard PPE Categories. These new PPE category tables only use Category 1 through 4 and no longer include tasks because Table 130.7(C)(15)(A)(a) addresses them. Zero is no longer there.


Without Category 0, does that mean arc flash PPE will always be required? No, since Arc Flash Hazard Identification Table 130.7(C)(15)(A)(a) indicates many tasks where arc flash PPE is not required. However, instead of identifying these cases by using zero, the table uses a yes/no format to verify if arc flash PPE is required.


Arc flash studies/risk assessments


What about arc flash studies using incident-­energy calculations? Such studies will frequently link incident energy to PPE levels such as 0, 1, 2, 3 and 4, which are then listed on the arc flash labels. This method normally uses Level 0 when the prospective incident energy is less than 1.2 cal/cm2. This is the generally accepted threshold where arc flash protection is required. Can arc flash labels still reference Level 0? Section 130.5(D) Equipment Labeling permits the use of site-specific PPE levels, so Level 0 can continue to be used as part of the labeling strategy.


What PPE is required?


Whether the Arc Flash Hazard Identification Table 130.7(C)(15)(A)(a) indicates no arc flash PPE is required or the arc flash labels from incident-energy calculations indicate Level 0 is to be used, is there still a minimum level or protection required?


Yes. NFPA 70E Article 130.7(C)(11) continues to prohibit the use of certain flammable, synthetic materials as it has in the past. This means, at a minimum, wear clothing made from nonmelting, natural fabric when arc flash PPE is not required. Other PPE may also be required as needed.


Even though HRC 0 and PPE Category 0 are not part of the 2015 edition of NFPA 70E, minimum protection requirements still exist and are inherent in the text of NFPA 70E.