What is NFPA 70E?
Published by the
National Fire Protection Association in 1979, NFPA
70E was written to protect electrical workers in
every industry around any type of device capable of
generating an arc flash. NPFA 70E is a “consensus
standard” referenced by the National Electric Code
for safety requirements. While it is currently
voluntary, each year more states, departments and
organizations are adopting NFPA70E. This increasing
rate of adoption can put those companies not
protecting their employees from this hazard at risk
for potential fines should an accident occur.
The
current NFPA 70E Standard for Electrical Safety in
the Workplace, 2009 edition was released September
2008. This edition includes the most up to
date requirements including charts to assist in
finding the right protective clothing for the job.
Some of
the major changes as it relates to protective
clothing include:
-
A
Face Shield has been added as a requirement to
meet Hazard/Risk Category 1.
-
12
oz. untreated denim cotton jeans are no longer
acceptable to meet Hazard/Risk Category 1
requirements. All pants must be flame
resistant.
-
100%
cotton underwear has been removed from the
layering calculation. The ATPV number is
solely based on the performance of the flame
resistant garment.
Federal
OSHA requires the employer to conduct hazard
assessments in accordance with 29 CFR 1910.132(d).
If an electric arc is present, OSHA deems the
employer to be in compliance if PPE is selected
using the NFPA 70E standard.
Who's
affected by NFPA70E?
Virtually any facility housing
electrical equipment falls under NFPA 70E guidelines,
especially in enterprises dependent upon heavy
machinery operations like-
- Aluminum
- Automotive
- Chemical
- Commercial Printers
- Computers and Chip Manufacturers
- Food Processing
- Hospitals
|
- Metal Fabrication
- Paint
- Petroleum
- Pharmaceutical
- Power Generation
- Pulp and Paper
- Transportation
|
Determine the Risk
Category
Compliance with NFPA 70E begins with
a hazard assessment of the job to be performed.
The simplest approach is to compare your desired job to
the list of common tasks found in Table 130.7 (c)(d),
and determine its corresponding Hazard/Risk Category or HRC, numbered from zero to four.
Then select the
appropriate garments for the job as shown in Table 130.7
(c)(11).
|
 |
NFPA 70E – Standard for Electrical
Safety in the Workplace: 2009 edition Table 130.7
(c)(11) Protective Clothing Characteristics
| |
| Hazard/Risk
Category |
Clothing
Description (Typical number of clothing layers is
given in parenthesis) |
Required
minimum Arc Rating of PPE cal/cm2 |
| 0 |
Non-melting,
flammable materials (i.e. untreated cotton, wool,
rayon or silk, or blends of these materials) with
a fabric weight at least 4.5 oz/yd2 (1) |
N/A |
| 1 |
Arc rated FR shirt and FR pants or FR coverall |
4 |
| 2 |
Arc rated FR shirt and FR pants or FR coverall |
8 |
| 3 |
Arc rated FR shirt and pants or FR coverall, and arc
flash suit selected so that the system arc rating
meets the required minimum |
25 |
| 4 |
Arc rated FR shirt and pants or FR coverall, and arc
flash suit selected so that the system arc rating
meets the required minimum |
40 |
Note: Arc rating can be either ATPV or
EBT. ATPV is defined as the incident energy
on a material or a multilayer system of materials that
results in a 50% probability that sufficient heat
transfer through the tested specimen is predicted to
cause the onset of a second-degree skin burn injury
based on a Stoll curve, cal/cm2. EBT
is defined as the incident energy on a material system
that results in a 50% probability of break open.
The greater the risk, the higher
the HRC level, with progressively higher minimum arc
ratings required for flame-resistant apparel. Measured
in cal/cm2, the arc rating is a garment’s incident
energy exposure that would just cause the onset of a
second degree burn 50 percent of the time.
To
order a copy of the 2009 edition of the NFPA 70E
Standard for Electrical Safety in the Workplace, visit http://www.nfpa.org/
Select the Apparel
 Each type of fabric
has unique characteristics affecting comfort,
wear life, cost, appearance, and arc rating
(which increase with heavier fabric weights).
Arc rating is also increased when
flame-resistant garments are layered (e.g.,
coveralls over a shirt and pant).
Though each HRC specifies a different arc rating
minimum, many companies simplify their needs by
choosing just two sets of clothing for their
people to handle all electrical tasks: (a) a
garment set with an arc rating of at least 8 for
the more routine tasks of HRC 0, 1 and 2; and
(b) a garment set with an arc rating of a least
40 for the more specialized tasks of HRC 3 and
4.
Our wide selection of garment styles and fabrics
provide both single and multi-layer options for
HRC 2 plus we offer apparel expressly made for
HRC 3 & 4 NFPA 70E compliance. These overalls,
coats, leggings and hoods minimize the number of
garments needed for HRC 3 and 4 tasks.
Browse
Workrite’s Catalog for NFPA 70E compliant
garments.
Workrite can help you assess the most
appropriate apparel for your needs.
For assistance contact one of our
Regional Account Executives.
or our customer service department at:
info@workrite.com
|
Layering of Garments
Workers may require multiple garments to
maintain safety while performing multiple tasks
within a day’s work. Layering is the sensible
answer that combines comfort, convenience and
safety.
The protection level provided through layering
is not simply a matter of adding up each
garment’s ATPV. Air, in ever-present layers amid
multiple garments and as the ultimate buffer
between garments and the skin, adds positively
to the safety equation. Loose fit, not snug fit,
is the goal as it creates a vital air ‘envelope’
for additional insulation.
The layering of FR garments is an alternative to
using specialized garments when developing
clothing systems to meet higher ATPV levels, for
example HRC 3 and 4. Picking the right FR
uniform combination can help you achieve the
required protection level.
A typical layering system may include a FR
shirt, FR pant and FR coverall. Combined, this
system can be mixed and matched in order to take
you to the appropriate ATPV rating. In addition
to garments, other PPE may be required to meet
the hazard risk category like head, eye and hand
protection.
|
Workrite’s Layering
Ensembles
Workrite carries
one of the largest varieties of branded fabrics
in the industry. They all vary in terms of
applicable hazards such as 70E, wear life, cost
– and perceived comfort.
To find out more about various fabrics check out
our
Overview of Fabrics on our website.
Examples of various garment layering
combinations and ATPV ratings are listed below:
| |
| Workrite Style |
Description |
ATPV |
HRC |
| 231UT70 |
7
oz. Ultra Soft Shirt |
|
|
| 431UT95 |
9.5
oz. Ultra Soft Pant |
|
|
| 131UT70 |
7
oz. Ultra Soft Coverall |
|
|
| |
|
27.2 |
3 |
| 231UT70 |
7
oz. Ultra Soft Shirt |
|
|
| 431UT95 |
9.5
oz. Ultra Soft Pant |
|
|
| 131UT95 |
9.5
oz. Ultra Soft Coverall |
|
|
| |
|
36.2 |
3 |
| |
| Workrite
Style |
Description |
ATPV |
HRC |
| 290NX45 |
4.5
oz. Nomex Shirt |
|
|
| 400NX75 |
7.5
oz. Nomex Pant |
|
|
| 110NX45 |
4.5
oz. Nomex Coverall |
|
|
| |
|
14.4 |
2 |
| 290NX45 |
4.5
oz. Nomex Shirt |
|
|
| 400NX75 |
7.5
oz. Nomex Pant |
|
|
| 110NX60 |
6
oz. Nomex Coverall |
|
|
| |
|
16.2 |
2 |
| 290BC45 |
4.5
oz. Nomex Blend Shirt |
|
|
| 433NX60 |
6
oz. Nomex Work Pant |
|
|
| 590NX60 |
6
oz. outershell,
9 oz Nomex Batt Insulation
Coverall |
|
|
| |
|
61.5 |
4 |
|
|
