Feature
Hand Protection for Shock and Arc Flash —
How Do I Apply OSHA
and NFPA 70E Requirements?
by Lynn Hamrick
ESCO Energy Services Company
T
his narrative provides information associated
with hand protection. It summarizes both current regulations and NFPA 70E. Additionally, it
provides recommendations associated with implementing
(vii)Protector gloves shall be worn over insulating
gloves, except as follows:
(A) Protector gloves need not be used with
Class 0 gloves, under limited-use conditions,
where small equipment and parts manipulation
necessitate unusually high finger dexterity.
Note: Extra care is needed in the visual examination of the glove and in the avoidance of
handling sharp objects.
(B) Any other class of glove may be used for
similar work without protector gloves if the
employer can demonstrate that the possibility
these regulations in the industrial environment.
As a starter, excerpts from OSHA requirements and
NFPA 70E are provided below as a basis for further
discussion.
29CFR1910, SubPart I – Personal
Protective Equipment
§ 1910.137 Electrical protective equipment
(b) In-service care and use.
(2) The following specific requirements apply to insulating blankets, covers, line hose, gloves, and sleeves
made of rubber:
(i) Maximum use voltages shall conform to those
listed in Table I-5.
(ii) Insulating equipment shall be inspected for
damage before each day’s use and immediately following any incident that can reasonably be suspected
of having caused damage. Insulating gloves shall be
given an air test, along with the inspection.
(iv) Insulating equipment found to have other
defects that might affect its insulating properties
shall be removed from service and returned for
testing….
(vi) Insulating equipment shall be stored in such
a location and in such a manner as to protect it
from light, temperature extremes, excessive humidity, ozone, and other injurious substances and
conditions.
www.netaworld.org Table I-5 – Rubber Insulating Equipment Voltage Requirements
Class of
Equipment
Maximum use
voltage(1) a-c - rms
Retest voltage(2)
a-c - rms
Retest voltage(2)
d-c - avg
0
1
1,000
5,000
20,000
7,500
10,000
40,000
2
17,000
20,000
50,000
3
26,500
30,000
60,000
4
36,000
40,000
70,000
1. The maximum use voltage is the a-c voltage (rms) classification of the
protective equipment that designates the maximum nominal design voltage of
the energized system that may be safely worked. The nominal design voltage
is equal to the phase-to-phase voltage on multiphase circuits. However, the
phase-to-ground potential is considered to be the nominal design voltage:
(1) If there is no multiphase exposure in a system area and if the voltage
exposure is limited to the phase-to-ground potential, or
(2) If the electrical equipment and devices are insulated or isolated
or both so that the multiphase exposure on a grounded wye circuit is
removed.
2. The proof-test voltage shall be applied continuously for at least 1 minute,
but no more than 3 minutes,
Summer 2006 NETA WORLD
of physical damage to the gloves is small and if
the class of glove is one class higher than that
required for the voltage involved. Insulating gloves
that have been used without protector gloves may
not be used at a higher voltage until they have
been tested ….
(viii) Electrical protective equipment shall be subjected to periodic electrical tests. Test voltages and
the maximum intervals between tests shall be in
accordance with Table I-5 and Table I-6.
Table S-5 – Approach Distances for Qualified Employees Alternating Current
Voltage Range (phase-to-phase)
300V and less
Over 300V, not over 750V
Over 750V, not over 2kV
Over 2kV, not over 15kV
Over 15kV, not over 37kV
Over 37kV, not over 87.5kV
Over 87.5kV, not over 121kV
Over 121kV, not over 140kV
Minimum approach distance
Avoid Contact
1 ft. 0 in. (30.5 cm).
1 ft. 6 in. (46 cm).
2 ft. 0 in. (61 cm).
3 ft. 0 in. (91 cm).
3 ft. 6 in. (107 cm).
4 ft. 0 in. (122 cm).
4 ft. 6 in. (137 cm).
Table I-6 – Rubber Insulating Equipment Test Intervals
Type of Equipment
When to test
Rubber insulating line hose
Rubber insulating covers
Rubber insulating blankets
Rubber insulating gloves
Rubber insulating sleeves
Upon indication that insulating value is suspect.
Upon indication that insulating value is suspect.
Before first issue and every 12 months thereafter.1
Before first issue and every 6 months thereafter.1
Before first issue and every 12 months thereafter.1
1
If the insulating equipment has been electrically testing but not issued for
service, it may not be placed into service unless it has been electrically tested
within the porevious 12 months.
29CFR1910, SubPart S — Electrical
§ 1910.333 Selection and use of work practices.
(a) General. Safety-related work practices shall be employed
to prevent electric shock or other injuries resulting from
either direct or indirect electrical contacts…
(2) Energized parts. If the exposed live parts are not
deenergized (i.e., for reasons of increased or additional
hazards or infeasibility), other safety-related work
practices shall be used to protect employees who may
be exposed to the electrical hazards involved. Such
work practices shall protect employees against contact
with energized circuit parts directly with any part of
their body or indirectly through some other conductive object. …. Specific work practice requirements are
detailed in paragraph (c) of this section
(c) Working on or near exposed energized parts.
(2) Work on energized equipment. Only qualified
persons may work on electric circuit parts or equipment
that have not been deenergized under the procedures
of paragraph (b) of this section. Such persons shall be
capable of working safely on energized circuits and shall
be familiar with the proper use of special precautionary
techniques, personal protective equipment, insulating
and shielding materials, and insulated tools.
NETA WORLD Summer 2006
(ii) Qualified persons. When a qualified person is
working in the vicinity of overhead lines, whether in
an elevated position or on the ground, the person may
not approach or take any conductive object without
an approved insulating handle closer to exposed
energized parts than shown in Table S-5 unless:
(A) The person is insulated from the energized
part (gloves, with sleeves if necessary, rated for the
voltage involved are considered to be insulation
of the person from the energized part on which
work is performed), or
(B) The energized part is insulated both from all
other conductive objects at a different potential
and from the person, or
(C) The person is insulated from all conductive
objects at a potential different from that of the
energized part.
§ 1910.335 Safeguards for personnel protection.
(a) Use of protective equipment.
(1) Personal protective equipment.
(i) Employees working in areas where there are
potential electrical hazards shall be provided with,
and shall use, electrical protective equipment that is
appropriate for the specific parts of the body to be
protected and for the work to be performed.
Note: Personal protective equipment requirements
are contained in subpart I of this part.
(ii) Protective equipment shall be maintained in
a safe, reliable condition and shall be periodically
inspected or tested, as required by 1910.137.
(iii) If the insulating capability of protective equipment may be subject to damage during use, the
insulating material shall be protected. (For example,
an outer covering of leather is sometimes used for
the protection of rubber insulating material.)
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NFPA 70E Table 130.2(C) Approach Boundaries to Live Parts for Shock Protection
(All dimensions are distance form live part to employee.)
(1)
(2)
(3)
(4)
(5)
Prohibited Approach Boundary (1)
Exposable Movable
Conductor
Exposed Fixed Circuit Part
Restricted Approach
Boundary (1); Includes
Inadvertent Movement
Adder
0 to 50
51 to 300
301 to 750
Not Specified
10 ft. 0 in.
10 ft. 0 in.
Not Specified
3 ft. 6 in.
3 ft. 6 in.
Not Specified
Avoid Contact
1 ft. 0 in.
Not Specified
Avoid Contact
0 ft. 1 in.
751 to 15 kV
15.1 kV to 36 kV
36.1 kV to 46 kV
10 ft. 0 in.
10 ft. 0 in.
10 ft. 0 in.
5 ft. 0 in.
6 ft. 0 in.
8 ft. 0 in.
2 ft. 2 in.
2 ft. 7 in.
2 ft. 9 in.
0 ft. 7 in.
0 ft. 10 in.
1 ft. 5 in.
46.1 kV to 72.5 kV
72.6 kV to 121 kV
138 kV to 145 kV
10 ft. 0 in.
10 ft. 8 in.
11 ft. 0 in.
8 ft. 0 in.
8 ft. 0 in.
10 ft. 0 in.
3 ft. 3 in.
3 ft. 2 in.
3 ft. 7 in.
2 ft. 1 in.
2 ft. 8 in.
3 ft. 1 in.
161 kV to 169 kV
230 kV to 242 kV
345 kV to 362 kV
11 ft. 8 in.
13 ft. 0 in.
15 ft. 4 in.
11 ft. 8 in.
13 ft. 0 in.
15 ft. 4 in.
4 ft. 0 in.
5 ft. 3 in.
8 ft. 6 in.
3 ft. 6 in.
4 ft. 9 in.
8 ft. 0 in.
500 kV to 550 kV
765 kV to 800 kV
19 ft. 0 in.
23 ft. 9 in.
19 ft. 0 in.
23 ft. 9 in.
11 ft. 3 in.
14 ft. 11 in.
10 ft. 9 in.
14 ft. 5 in.
Nominal System Voltage
Range, Phase to Phase
Limited Approach Boundary (1)
Notes:
For SI units 1 in. = 25.4 mm 1 ft. = 0.3048 m
For flash protection boundary see 130.3(A)
(1) See definitions in Article 100 and text in 130.2(D)(2) and Annex C for elaboration.
NFPA 70E, Standard for Electrical Safety in
the Workplace — 2004
130.2(C) Approach to Exposed Live Parts Operating at
50 Volts or More. No qualified person shall approach or
take any conductive object closer to exposed live parts operating at 50 volts or more than the Restricted Approach
Boundary set forth in Table 130.2(C), unless any of the
following apply:
(1) The qualified person is insulated or guarded from
the live parts operating at 50 volts or more (insulating
gloves or insulating gloves and sleeves are considered
insulation only with regard to the energized parts upon
which the work is being performed), and no uninsulated
part of the qualified person’s body crosses the Prohibited
Approach Boundary set forth in Table 130.2(C).
(2) The live part operating at 50 volts or more is insulated from the qualified person and from any other
conductive object at a different potential.
(3) The qualified person is insulated from any other
conductive object as during live-line, bare-hand work.
www.netaworld.org 130.7(C)(6) Hand and Arm Protection. Employees shall
wear rubber insulating gloves where there is danger of hand
and arm injury from electric shock due to contact with live
parts. Hand and arm protection shall be worn where there
is possible exposure to arc flash burn. The apparel described
in 130.7(C)(13)(c) shall be required for protection of hands
from burns. Arm protection shall be accomplished by apparel described in 130.7(C)(5).
130.7(C)(13)(c) Hand Protection. Leather or FR gloves
shall be worn where required for arc flash protection. Where
insulating rubber gloves are used for shock protection,
leather protectors shall be worn over the rubber gloves.
FPN: Insulating rubber gloves and gloves made from
layers of flame-resistant material provide hand protection against the arc flash hazard. Heavy-duty leather
(e.g., greater than 12 oz/yd2) gloves provide protection
suitable up to Hazard/Risk Category 2. The leather
protectors worn over insulating rubber gloves provide
additional arc flash protection for the hands. During
high arc flash exposures leather can shrink and cause a
decrease in protection.
Summer 2006 NETA WORLD
Discussion
From Section 1910.333 of the OSHA requirements, it
is stated that rubber insulating gloves should be worn as
personal protective equipment (PPE) whenever a qualified
person is working inside of the clearance distance provided
in Table S-4. NFPA 70E specifies that rubber insulating
gloves should be worn when a qualified person breaches
the Restricted Approach Boundary, as defined in Table
130.2(C). If one closely examines these tables, one would
recognize some slight discrepancies in the associated distances. It is suggested that the NFPA 70E table be used since
it is more restrictive. It should be noted that only qualified
persons are allowed inside these boundaries. Further, it
should be noted that these requirements are associated with
shock protection only.
With respect to arc flash protection, NFPA 70E requires
both unqualified and qualified persons, to wear leather or FR
gloves whenever they breach the Flash Protection Boundary. This requirement suggests that leather covers should
always be worn when rubber insulating gloves are being
worn. OSHA requirements in 1910.137 also require that
protective covers be worn with rubber insulating gloves, but
these requirements include exceptions to wearing the covers,
particularly when high finger dexterity becomes an issue.
Unfortunately, the more recent guidance of NFPA 70E
supercede these exceptions due to arc flash requirements;
therefore, leather covers should always be used where rubber
insulating gloves are required for shock protection.
To summarize the discussion so far, the following requirements apply to wearing protective gloves:
1. Rubber insulating gloves should be worn whenever a
worker breaches the Restricted Approach Boundary.
2. Leather or FR gloves should be worn whenever a
worker breaches the Flash Protection Boundary.
3. Leather protective covers should be worn over the
rubber insulating gloves whenever the worker will be
breaching both the Restricted Approach Boundary
and the Flash Protection Boundary.
Since 1910.137 has been published, a Class 00 glove has
been approved for use. This glove classification has a use
voltage of 500 volts with a testing voltage of 2,500 volts.
In addition to observing the previously discussed requirements, one should always use gloves that fit properly. This
will minimize the chaffing and hand fatigue. When selecting
a glove size, measure the circumference around the palm.
Allow for additional room if fabric or thermal glove liners
are to be worn.
When purchasing gloves, purchase the matching leather
covers at the same time and always retain the canvas bag
that come with the gloves. The leather covers should be
shorter than the rubber insulating gloves to minimize the
potential for electrical tracking when in use. Also, exposure
to sunlight and fluorescent lighting will greatly reduce the
useful life of rubber insulating gloves. When the gloves are
not being used, they should be stored in a dark place. The
canvas bags are an ideal storage container.
As Operations Manager of ESCO Energy Services Company, Lynn
brings over 25 years of working knowledge in design, permitting, construction, and startup of mechanical, electrical, and instrumentation and
controls projects as well as experience in the operation and maintenance
of facilities.
Lynn is a Professional Engineer, Certified Energy Manager and has
a BS in Nuclearn Engineering from the University of Tennessee.
From 1910.137, other requirements are provided associated with the use of rubber insulating gloves. The gloves
should be inspected and air tested every time they are used.
Further, rubber insulating gloves should be proof-tested
every six months. These activities should minimize the potential for the gloves not protecting the worker when used
in the workplace. The worker should also be cognizant of the
difference between the testing voltage and the use voltage.
The glove classification and the testing voltage are required
to be identified on the cuff of the glove. This could provide
the worker with a false sense of security if the testing voltage is mistaken for the use voltage. It is the responsibility
of the qualified worker to know the difference and to apply
them correctly.
NETA WORLD Summer 2006
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