NFPA 70e:
National Fire Protection Association’s Standard for
Electrical Safety in the Workplace is a voluntary standard
that is widely considered to be the best practice guide for
protecting workers from arc flash. It addresses electrical
safety requirements in workplaces during activities such as
the installation, operation, maintenance, and demolition of
electric conductors, electric equipment, communications
equipment, and raceways.
The essence of NFPA 70e, from a Personal Protection
Equipment (PPE) perspective, is to identify the threat and
accurately match your PPE to the threat. It is beyond the
scope of this website to explain NFPA 70e, but we do
recommend visiting for complete

HRC is an abbreviation for Hazard/Risk Category. This is a
classification system published in NFPA 70e which is used
to match protective clothing and equipment to tasks
performed on energized equipment.
Note: There are five Hazard/Risk Categories (0, 1, 2, 2*, 3
and 4) with clothing system arc rating requirements ranging
from 0 to 40 cal/cm2. See NFPA 70e, Table 130.7(C) (11)
and Article 130 for complete information.

Arc Rating:
An arc rating can be reported as ATPV or Ebt and it is used
to match protective clothing and equipment to the threat.
ATPV stands for Arc Thermal Performance Value and is
expressed in cal/cm2. Some people in the industry may refer
to this as “Cals”, and while this term is not recognized by
code, it is short for calories-per-square-centimeter. This
measure represents the amount of energy a material will
block until there is a 50% probability that there would be a
second degree burn. This number describes the protective
clothing’s ability to resist heat.
Incident Energy, which is the amount of energy from an
electrical arc that is likely to be experienced at a certain
distance, describes the threat. It too is expressed in cal/cm2.

ASTM 1506:
This is “Standard Performance Specification for Flame
Resistant Textile Materials for Wearing Apparel for Use by
Electrical Workers Exposed to Momentary Electric Arc and
Related Thermal Hazards.”
It sets the minimum performance criteria for fabric that is
used as a flame resistant garment. It includes requirements
for flame travel, seam strength, tearing, bursting strength and

NESC 2007:
The National Electrical Safety Code (NESC) has been
adopted by municipalities and states around the country. It
was designed for people working on electrical supply, utilities,
communications and associated equipment. It compliments the
NFPA 70e code because it provides practical work rules for
electrical generation, distribution and communication, or
people who must work on or near energized parts because it is
not possible or practical to de-energize.
There are three clothing system ratings in this code 4-cal, 8-cal
and 12 cal systems which are based on voltage, fault current
and maximum clearing times for voltages up to 800kV.

NFPA 2112:
This is a flame resistant garment standard for protection of
industrial personnel against a flash fire. This standard contains
dozens of tests which the material, fabric, accessories and
garment must pass. For example, the garment must achieve
less than a 50% total body burn, as tested on a thermal
mannequin. The fabric must maintain flame resistant
properties after 100 commercial washes, a low thermal
shrinkage, maintain colorfastness and a host of other design
standards which are all part of NFPA 2112. For more
Note: It is important to note you cannot certify a fabric, but
only a garment to this standard. Many brands of flame
resistant garments can not pass this test.

OSHA 1910.269:
This Occupational Safety and Health Administration standard
applies to electric utilities and generation plants when work is
performed on existing facilities. It requires that employees
who work around energized electrical parts not wear clothing
that, when exposed to flames or electric arc, does not
contribute to the extent of the burn injury. In common
language, it requires that in the event of a hazardous incident,
your clothing can not make the injury worse.
This means do not wear clothing that will support combustion,
melt, or have high rates of thermal shrinkage. This rule
prohibits polyester, nylon and other synthetic non-FR
Flame resistant clothing that meets the requirements of ASTM
F 1506 “Standard Performance Specification for Flame
Resistant Textile Materials for Wearing Apparel for Use by
Electrical Workers Exposed to Momentary Electric Arc and
Related Thermal Hazards” complies with OSHA

OSHA 1910.32:
This is a broad explanation of the employers’ responsibility to
their employees. In general terms, it states that it is the
employers’ duty to identify potential danger and protect the
employee from those hazards. OSHA has used this “General
Duty Clause” to cite employers who did not require the use of
flame resistant clothing after their employees were burned.

SANS 724

Personal protective equipment and protective clothing against the thermal hazards of an electric arc. Covers the design, SANS 724:2010
selection and performance requirements of electric arc resistant clothing and equipment for the protection of persons against the thermal hazards of an electric are, which could occur during operating or working on or near electrical equipment in the workplace.