James R. White, VP of Training Services, Shermco Industries, for Fluke
With the recent release of the 2018 edition of the NFPA 70E standard, many users are finding it challenging to interpret what it says and prioritize where they should focus their attention. The short answer is that the entire 70E standard is important; not just one chapter, article or section. However, this article highlights 10 changes that the author believes are most important.
New Table 130.5(C), Estimate of the Likelihood of Occurrence of an Arc Flash Incident for ac and dc Systems
This table replaces Table 130.7(C)(15)(A)(a), Arc Flash Hazard Identification for Alternating Current (ac) and Direct Current (dc) Systems in the 2015 70E standard. (See figure 1a.) In addition to the title and location change, the new Table 130.5(C) in the 2018 standard changed the third column heading from “Arc Flash PPE Required” to “Likelihood of Occurrence”. Section 130.5(C) of the 2018 standard also states that “Table 130.5(C) shall be permitted to be used to estimate the likelihood of occurrence of an arc flash event to determine if additional protective measures are required.” Use of arc flash-rated clothing and PPE is one of the additional protective measures listed. (See Figure 1b.)
Figure 1a
Table 130.7(C)(15)(A)(a) (Partial) NFPA 70E 2015 Edition
Figure 1b
Table 130.5(C) (Partial) NFPA 70E 2018 Edition
Why the change?
The 70E standard is written for field electrical workers, not for engineers or attorneys, although they may use it. Over the last several cycles, the 70E committee has tried to improve the usability of the standard, especially the arc flash PPE tables, to make it much easier for field electrical workers to use. By moving Table 130.5(C) into the body of the standard it can be used as part of an arc flash risk assessment for both the Table Method and when arc flash warning labels are used.
Bottom line:
The new table is useful, but it cannot take the place of experience or expertise. This table should be used cautiously. The person in front of the equipment about to perform a task must determine its suitability and assess the equipment's condition, including its condition of maintenance, before performing that task. Use of this table is “permitted”, meaning it's an option—it can be used, but is not mandatory. At the end of Table 130.5(C) it states that to use the table, equipment must be in normal operating condition:
“Equipment condition considered to be 'normal' if all of the following circumstances apply:
- The equipment is properly installed in accordance with the manufacturer's recommendations and applicable industry codes and standards.
- The equipment is properly maintained in accordance with the manufacturer's recommendations and applicable industry codes and standards.
- The equipment is used in accordance with instructions included in the listing and labeling and in accordance with manufacturer's instructions.
- Equipment doors are closed and secured.
- Equipment covers are in place and secured.
- There is no evidence of impending failure such as arcing, overheating, loose or bound equipment parts, visible damage, or deterioration.”
Be sure also to read and understand the note (*) at the end of the table that states, in part:
“The estimate of the likelihood of occurrence contained in this table does not cover every possible condition or situation, nor does it address severity of injury or damage to health. Where this table identifies “No” as an estimate of likelihood of occurrence, it means that an arc flash incident is not likely to occur. Where this table identifies “Yes” as an estimate of likelihood of occurrence, it means that additional protective measures are required to be selected and implemented according to the hierarchy of risk control identified in 110.1(H).”
Be aware that “Not likely to occur” does not mean it won't happen. It just means there is a reduced risk of occurrence. Use your best judgement, in addition to this table, when assessing risk.
DC voltage shock threshold changed back to 50V
This threshold was changed back to 50V from 100V to comply with OSHA regulations.
Why the change?
In the 2015 70E review cycle the shock threshold for dc volts was changed to 100 Vdc (See Figure 2a) after a majority the 70E committee was convinced to do so by a very convincing dissertation from a well-respected speaker.
Figure 2a
Table 130.4(D)(b) (Partial) NFPA 70E 2015 Edition
Although technically, the speaker was correct, OSHA didn't agree with him. So during the 2018 review cycle OSHA distributed a Letter of Interpretation to the committee, dated September 4, 2015 that stated that OSHA would cite any employer who did not observe its 50 Vac or Vdc threshold. The letter included examples where workers had been killed by voltages under 50 V. Based on the input from OSHA, the committee reversed its stance on the shock threshold and went back to the 50 Vdc value. (See Figure 2b.)
Figure 2b
Table 130.4(D)(b) (Partial) NFPA 2018 Edition
Bottom line:
The shock threshold for ac and dc voltages is once again 50 V to comply with OSHA regulations. This is based on a section of the Foreword in the 70Estandard that states “The committee would develop a standard for electrical installations that would be compatible with the OSHA requirements for employee safety...”
New Table 130.5(G), Selection of Arc-Rated Clothing and Other PPE When the Incident Energy Analysis Method Is Used
In the 2018 70E standard, Table 130.5(G) replaces Table H.3(b) from the 2015 standard. The new table provides guidance on how to select PPE when using the incident energy analysis method and was moved to the body of the standard.
Why the change?
In previous editions of the 70E standard Table H.3(b) (see Figure 3a) was located in Informative Annex H. Workers commented that there was no method for selecting all the PPE required when using the incident energy analysis method, because Table H.3(b) was in Annex H and anything in the annexes is not considered part of the standard. As a result, Table H.3(b) was not being used as intended. In the 2018 70E the table was modified to eliminate any clothing or PPE under 1.2 cal/cm2, because it only deals with arc-rated clothing and other PPE. The table was renamed Table 130.5(G) and put into the body of the standard. Its use is “permitted”, meaning it's an option—it can be used, but is not mandatory.
Figure 3a
Table H.3(b) (Partial) NFPA 70E 2015 Edition
Figure 3b
Table 130.5(G) (Partial) NFPA 70E 2018 Edition
Bottom line:
If arc-rated clothing and PPE is to be selected using arc flash warning labels, Table 130.5(G) can be used to assist in choosing arc-rated and other PPE. Users are cautioned not to mix the Table Method with the incident energy analysis method for selecting their arc-rated clothing and PPE. The two methods are not compatible and could cause issues. The Table Method is used when estimating the available fault current and operating time of the overcurrent protective device (OCPD). Table 130.5(G) is used when the equipment has arc flash warning labels on it.
70E Committee sets minimum CPR and First Aid training intervals
The 2018 70E edition now states in 110.2(C)(2)(d) “Training shall occur at a frequency that satisfies the requirements of the certifying body.” Thus the 70E committee that it sets minimum requirements for CPR and First Aid training, not best safe work practices.
Why the change?
In previous editions of the 70E, CPR, First Aid, and AED training were required annually. This may have been more frequent than the requirements set by various organizations (such as the American Heart Association (AHA), for the general public, but electrical workers face a much greater risk from ventricular fibrillation due to shock than the general public.
During the 2018 70E review cycle the issue came up that the 70E does not set best safe work practices; it sets minimum requirements. Companies are to meet or exceed the requirements in the 70E.
Bottom line:
The idea of the 70E standard setting minimum standards vs. best safe work practices has been the subject of several discussions among committee members in the past. In general, the committee has voted to establish that the 70E standard indeed sets minimum requirements, not best safe work practice. As part of that approach, the standard states that the training interval requirement follows that of the certifying body. For example, if the American Heart Association's interval for recertification is two years, that is the new requirement from the 70E. However, as a practical matter workers are probably not going to remember how to perform CPR or First Aid under the stresses of an emergency situation, knowing that someone's life could hang in the balance, after more than a year. So the author strongly recommends annual training for CPR, First Aid, and/or AED use (if an AED is available at the work site.)
Forget the 40 cal/cm2 incident energy threshold
Incident energy is not a good measure of the pressure wave that might be created by an arc event. The committee did not want workers to think that an arc event under 40 cal/cm2 was not serious, so the threshold was deleted.
Why the change?
In previous editions, the 70E contained an Informational Note in 130.7(A) that stated, “When incident energy exceeds 40 cal/cm2 at the working distance, greater emphasis may be necessary with respect to de-energizing when exposed to electrical hazards.” This was the “line in the sand” companies and workers used to determine what was safe and what could not be worked on. However, that is not what the Informational Note said. It only stated that extra efforts should be made to de-energize equipment, not that it could not be worked on. In general, most people would say that equipment rated above 40 cal/cm2 is off limits. I'm good with that.
The problem with that Informational Note is that it was created during the 2000 review cycle. Our understanding of arc flash and arc blast has changed considerably since then. There are situations when incident energy below 40 cal/cm2 might be more hazardous than when it is above that level. For example, a fault that releases 40 cal/cm2 over 30 cycles will create less arc pressure than one that releases its energy in two cycles, all things being equal. We now know that pressure wave (arc blast) is related to the fault current, not incident energy, because it is an instantaneous event.
Bottom line:
There is no such thing as a “safe” arcing fault. Incident energy is not a good measure of the pressure wave that might be created by an arc. Equipment rated above 40 cal/cm2 should be de-energized before being worked on. But equipment rated below that level should be because an arc event under 40 cal/cm2 can be serious as well.
The first permanently mounted absence-of-voltage test device is approved
A new exception was added to section 120.5, which states “Exception No. 1: An adequately rated permanently mounted test device shall be permitted to be used to verify the absence of voltage of the conductors or circuit parts at the work location, provided it meets the all following requirements:
- It is permanently mounted and installed in accordance with the manufacturer's instructions and tests the conductors and circuit parts at the point of work;
- It is listed and labeled for the purpose of verifying the absence of voltage;
- It tests each phase conductor or circuit part both phase-to-phase and phase-to-ground;
- The test device is verified as operating satisfactorily on any known voltage source before and after verifying the absence of voltage.”
Why the change?
This is a watershed moment for the 70E. In the past, the committee has been approached by manufacturers of LED indicator lights wanting to gain approval for their devices as an absence-of-voltage tester. We pointed to the OSHA Letter of Interpretation dated December 12, 2012, which states in part”.
“ Question 1: Can the type of device described above be used to verify that isolation and de-energization of the machine or equipment have been accomplished under 29 CFR 1910.147(d)(6)?
Response: No. However, the type of device that you describe, if installed correctly and maintained, might serve only as a redundant indicator that the disconnecting device is in the open ("off") position.”
In the 2018 review cycle a company presented a product that met a new UL standard and meets the requirements of a true absence-of-voltage tester. (See Figure 4.) The committee questioned both the company's representative and the UL representative at length, and determined that the device presented was acceptable. The new exception noted above was then added to 120.5.
Bottom line:
An LED indicator light is not an absence-of-voltage test instrument. At the time of this writing, there is only one such test instrument currently manufactured. LED indicator lights can provide a first indication, but a qualified person must still perform a manual absence-of-voltage test using a hand-held test instrument and test phase-to-phase and phase-to-ground.
Figure 4
Permanently mounted absence-of-voltage test device
All mandatory reference to other standards are removed
Standards that had been mandatory are now contained in Informational Notes. For example, one mandatory reference in the 2015 edition of 70E—130.7(F)—has been renumbered to 130.7(G) and now reads “Other protective equipment required in 130.7(D) shall conform to the applicable state, federal, or local codes and standards.
Informational Note: The standards listed in Table 130.7(G), which is part of this Informational Note, are examples of standards that contain information on other protective equipment.”
This change generated a lot of discussion among committee members, especially those from the standards organizations. In past editions, the 70E has stated that arc-rated clothing and PPE must meet the ASTM standards for those articles of PPE. This was done to prevent unsafe PPE, especially arc-rated clothing and PPE, from being used by workers.
Why the change?
The NFPA wanted to remove mandatory references to other standards because the 70E is used in many countries, not just the US. Requiring another country to follow a US-based standard when it may be required by law to follow another, created conflicts. So mandatory references to other standards were removed.
Bottom line:
In most cases PPE is mandated by OSHA to meet ASTM and other standards, so this is not as serious as some expressed. This author would have kept the mandatory references to other standards, but acknowledges that it does limit the use of the 70E in other countries which do not use US standards.
New requirement for a conformity assessment for PPE
Section 130.7(C)(14)(b) requires that PPE comply with a conformity assessment. This requirement is based on ANSI/ISEA 125, American National Standard for Conformity Assessment of Safety and Personal Protective Equipment. Informative Annex H.4 contains detailed information about the conformity assessment requirements.
Why the change?
With mandatory references to other standards eliminated in the 70E, the committee believed that another mechanism was needed to ensure workers were provided with adequate arc-rated clothing and other types of PPE. Figure 5 below illustrates the importance of conformity assessments, even when there were mandatory requirements to meet ASTM standards. The clothing in Figure 5 was purchased because it had an ATPV (Arc Thermal Performance Value or arc rating) on a label and stated it had an HRC 2 rating.
Figure 5
Garment is mislabeled. It is not arc-rated
The inside label stated that it meets NFPA 2112 for flash fires, but makes no mention of ASTM F1506. Workers in refineries and the like are often required to wear flame resistant (FR) protective clothing that meets NFPA 2112. However, electrical workers face a risk of arc flash. The difference? Flash fires are slow burning and the heat is much less. Arc flashes produce extreme heat for a very short period of time. Thus, electricians must wear F1506 (arc-rated) clothing.
Bottom line:
The clothing above is FR, not arc-rated and is inadequate for workers exposed to arc flash events. The clothing can be rated for both, but this example clearly does not state that it meets the requirements for arc-rated clothing. A conformity assessment would have caught this issue.
Revised footnote for Table 130.7(C)(7)
The footnote was revised to make it clear that new rubber insulating gloves being placed into service are required to have been tested within 12 months.
Figure 6
Revised table footnote in the 2018 edition
Why the change?
The previous table footnote was unclear. Even the representatives from OSHA and ASTM did not share the same opinion. However, the 70E committee and OSHA and ASTM representatives agreed that rubber insulating gloves should go no longer than 12 months without being tested. According to the OSHA representative, gloves are considered placed into service when they are purchased, not when they are handed out. He noted that rubber insulating gloves are tested when they are manufactured, but could sit up to two years before being purchased by the end user. So the committee decided to revise the footnote to make its meaning more understandable. (See Figure 6.)
Bottom line:
When gloves are purchased they should be tested. They should then be tested every six months afterwards. If they are not in service, they can sit for up to 12 months, but then would require testing. Once tested, they must be tested every six months thereafter.
New human error risk assessment procedure
Section 110.1(H)(2) is a new requirement covering the risk assessment procedure for “Human Error”. It states:
“ (2) Human Error. The risk assessment procedure shall address the potential for human error and its negative consequences on people, processes, the work environment, and equipment. Informational Note: The potential for human error varies with factors such as tasks and the work environment. See Informative Annex Q.”
New Informative Annex Q provides excellent guidance on human performance and its relationship to workplace safety. It includes human performance modes and their associated errors, tools to improve human performance, and human performance warning flags.
Why the change?
Experts estimate the percentage of incidents caused by some form of human failure to be from 75% to 85%. With that percentage of incidents so high, it is reasonable that efforts be made to try to reduce the number of human errors.
Bottom line:
If no effort is made to account for human performance errors, the chances of them occurring increase. This author doubts that anyone could list all the human errors possible for any one task. But that is not the intent of this new requirement or Informative Annex Q. The goal of the requirement is to try to determine what errors could be made, then apply human performance tools to try to account for them.
Conclusion
This article only touches on some of the revisions to the 2018 edition of NFPA 70E. Many recurring or global changes are not covered here. The NFPA 70E committee reviews the actions it has taken in the past, then tries to improve what is written to make the 70E as clear and usable for the field service technician as possible. It is up to the user to interpret the 70E and apply it in the workplace. The author suggests that each user visit the NFPA 70E page and review the actions and committee statements for each action. These provide even more insight into why the committee took a specific action and the intent of that action.
James (Jim) R. White, Vice President of Training Services, has worked for Shermco Industries Inc. since 2001. He is a National Fire Protection Association (NFPA) Certified Electrical Safety Compliance Professional (CESCP) and a NETA Level IV Senior Technician. Jim is NETA's principle member on NFPA Technical Committee NFPA 70E ® Standard for Electrical Safety in the Workplace ®, NETA's principle representative on National Electrical Code ® (NEC ®) Code-Making Panel (CMP) 13, and represents NETA on ASTM International Technical Committee F18 Electrical Protective Equipment for Workers. Jim is Shermco Industries' principal member on NFPA Technical Committee for NFPA 70B: Recommended Practice for Electrical Equipment Maintenance and represents AWEA (American Wind Energy Association) on the ANSI/ISEA Standard 203 Secondary Single-Use Flame Resistant Protective Clothing for Use Over Primary Flame Resistant Protective Clothing. An IEEE Senior Member, Jim received the IEEE/IAS/PCIC Electrical Safety Excellence Award in 2011 and NETA's Outstanding Achievement Award in 2013. Jim was Chairman of the IEEE Electrical Safety Workshop in 2008 and is currently Vice-Chair for the IEEE IAS/PCIC Safety Subcommittee. With offices stretching from Houston, TX to Regina, Saskatchewan, Canada, Shermco has several infrared thermographers in the field at any one time.
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