ARCFLASHSAFETY BY JIM PHILLIPS
PHILLIPS, P.E., founder of www.brainfiller.com and www.ArcFlashForum.com,
conducts training programs around the world and is author of “Complete Guide to Arc Flash
Hazard Calculation Studies.” He is secretary of the IEEE 1584 Arc Flash Working Group and
a member of many other national and international standards organizations. Reach him at
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
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.
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 equip-
ment in such a manner that could cause
an electric arc.”
Since then, the use of “interacting”
has continued to raise quite a few ques-
tions. 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
• 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
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
Without Category 0, does that mean
arc flash PPE will always be required?
No, since Arc Flash Hazard Identifica-
tion Table 130.7(C)( 15)(A)(a) indicates
many tasks where arc flash PPE is not
required. However, instead of identify-
ing 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.
Less Than Zero
2015 NFPA 70E “0” for PPE selection—deleted
“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?