Ok I’ll admit it, I chose that title because I wanted to get
your attention. But in my experience (and in my defense), a lot of companies
don’t understand what OSHA requires when it comes to electrical safety. So let’s talk OSHA, and more specifically their
Electricity is a wonderful thing. We use it to power our homes, machines, tools, lighting, medical equipment… the list could go on forever. Electricity is also a frightening thing. Coming into contact with an electrical circuit can lead to shock (whether minor or severe), electrocution (shock leading to death), arc flash, arc blast, and burns. Electrical energy remains one of the most serious hazards in the workplace, yet accidents are often avoidable. Electrical accidents are typically caused by either unsafe conditions, such as poorly maintained equipment, loose connections, or insulation failure, or by unsafe work practices, such as not de-energizing prior to work or using conductive tools. Often, it’s a combination of both.
Breakdown of the
To avoid boring you with numerous regulation references, I’ll
give you a quick overview of OSHA’s electrical safety standard. There are two
electrical standards, one for General Industry (29 CFR 1910, Subpart S)
and one for Construction (29 CFR 1926, Subpart K). Given the consistency
between both standards, I’ll focus on Subpart S. OSHA’s Electrical standard is broken down
into 4 divisions:
- Design Safety Standards
- Safety-Related Work
- Safety-Related Maintenance Requirements
- Safety Requirements for Special Equipment
Be sure to remember the names of the first two divisions. I mention them quite a bit in this article and they are discussed in detail below.
What Applies to Me?
One of the first questions to ask yourself is whether or not
you are covered under the electrical safety requirements. Chances are if you
have electrical equipment, at least some of OSHA’s electrical requirements are
going to apply to you. Although there are exceptions, the design safety
requirements cover all electrical equipment used in buildings, on
structures, on your premises, or on other premises (if the equipment is your
The safety-related work practice requirements cover
all of your employees, whether qualified or unqualified, if they face a risk of
electric shock above 50 volts. If employees face a risk of shock, OSHA requires
them to be trained and familiar with certain parts of the standard.
Design Safety Requirements
To start, let’s focus on equipment safety (which in turn
helps keep employees safe). A lot of information is contained in this set of
requirements, 1910.302-.308. The highlights are provided below – and yes,
believe it or not, it’s a very condensed version!
OSHA requires the following:
- Electric equipment must be examined to ensure it
is free from serious recognized hazards. Employers should consider
equipment insulation, heating effects, arcing effects, wire bending, mechanical
strength, listing/labeling (by a nationally recognized testing laboratory), and
- Electric equipment must be installed according
to its listing/labeling instructions (by a nationally recognized testing
- Electric equipment must be located away from
damp or wet areas, including areas with gases, fumes, vapors or liquids, unless
specifically rated for that location.
- Circuit breakers and switchboards located in wet
areas must be enclosed in weatherproof enclosures.
- Openings in electrical boxes, cabinets, panels,
etc. must be closed up (not with tape or paper).
- Internal parts of equipment must not be
contaminated with paint, cleaners, or corrosives.
- Electric equipment must be firmly secured to the
surface on which it’s mounted.
- Electric equipment must be marked with the
manufacturer’s name or trademark, and the system voltage, current, wattage, or
- Disconnect switches, circuit breakers, or other
overcurrent devices must be marked to identify their purpose when it’s not
- Disconnect switches must be capable of being locked
out (according to lockout/tagout).
- For equipment 600 volts or less, at least
36-inches of clearance must be provided in front of the equipment.
- Panel doors or hinged panels must be able to
open at least 90 degrees.
- The minimum headroom above the equipment,
starting from the floor, should total no less than 6.5 feet. So it’s important
not to store materials on top of electrical panels and equipment.
- When live electrical parts are exposed for
inspection/service in a passageway or open area, the working space must be
guarded to keep unqualified personnel away.
- When live electrical parts are exposed in a room
or guarded location, warning signs should be posted forbidding unqualified
persons to enter.
- When live electrical parts are exposed and the
equipment is over 600 volts, the entrance to that area must be kept
locked unless employees are supervised by a qualified person. A sign should be
posted reading ‘Danger – High Voltage – Keep Out.’
- Adequate lighting should be provided around all
- Live parts of equipment at 50 volts or higher
must be guarded against accidental contact either by 1) locating it in an area
only accessible to qualified persons; 2) placing permanent screens/partitions
around the equipment; 3) placing it on a platform or balcony only accessible to
qualified persons; or 4) elevating it up above 8 feet from the floor.
- If electric equipment is susceptible to physical
damage, e.g., overhead lighting, it should be protected with guards.
- All 120-volt receptacles in restrooms and on
rooftops must be protected with a ground fault circuit interrupter (GFCI).
- If more than one extension cord is used or if
one extension cord powers multiple pieces of equipment, the outlet must be
protected with GFCI. For construction activities, extension cords must always
be protected with a GFCI.
- Equipment must be protected from overcurrent
with overcurrent protective devices (circuit breakers, fuses). These devices
must be accessible to each employee or authorized management personnel.
- Circuit breakers used for facility lighting must
be rated to operate as a switch. The breaker will be marked ‘SWD’.
- Temporary wiring, i.e., extension cords may only
be used for a period of 90 days or less. It should be removed when the project
(renovations, holiday lighting, construction) is complete.
- Flexible cords/cables should not run through
holes in the floor, ceiling or walls, or through doorways or windows.
- Strain relief must be provided for cords/cables
to prevent the pull on joints or terminal screws.
- Employees must not be exposed to live parts of
appliances (other than open heating elements like toasters), lighting fixtures,
- If equipment is in place or installed in a
hazardous (classified) location, such as a room where flammable vapors can be
released or where combustible dust is a hazard, it must be approved for that
environment according to OSHA’s Class-Division system.
Now let’s focus on employee safety. There is not as much
information contained in 1910.331-.335, so it’s easier to digest. OSHA
addresses two groups of people – unqualified workers and qualified workers.
Unqualified workers are those employees who face a risk of
electric shock (above 50 volts) or other related injuries, but who have not
been trained to recognize and avoid the hazards associated with electrical
equipment. In other words, they are not trained nor permitted to work with live
electrical components. Unqualified workers must receive some level of training
that includes the following elements:
- Safety-related work practices that pertain to
their job tasks; and
- Inherent hazards of electricity (high voltages,
arc flash, lack of guarding, etc.).
If any of your employees have replaced a fuse, a circuit
breaker, or conducted voltage testing, to name a few, they are technically
doing “live” or “energized” electrical work.
They should be considered your qualified workers, but don’t be too quick
to label these workers right away. OSHA
defines a qualified person as someone
“who has received training in and has demonstrated skills
and knowledge in the construction and operation of electric equipment and
installations and the hazards involved.” Essentially, there are two
pieces to the qualified-person puzzle: 1) Skills and knowledge related to the
equipment; and 2) Training on the hazards. Your employees may be “qualified” to
do a particular task or work on a certain piece of equipment, but they may not
be qualified, i.e., they lack the skills and knowledge, for a different task or
piece of equipment.
Qualified persons should be trained on the following
- The skills and techniques necessary to distinguish between exposed live parts from other parts of the equipment;
- The skills and techniques necessary to determine the nominal voltage of exposed live parts;
- The clearance distances for overhead lines (if applicable);
- The approach boundaries for equipment at corresponding voltages;
- Proper use of special precautionary techniques, applicable electrical policies and procedures, PPE, insulating and shielding materials, and insulated tools;
- The construction and operation of equipment;
- Performing job safety planning;
- Identifying electrical hazards and assessing the associated risk;
- Selecting the proper risk control methods, including PPE; and
- Selecting the appropriate test equipment, using it safely, and interpreting it correctly.
There are additional requirements in this section beyond
training. The major highlights are provided below.
OSHA requires the following:
- Safety-related work practices (some of which may
have to be specific to your unique industry or equipment) must be used to
prevent shock and other related injuries.
- All equipment must be worked in a de-energized
state unless you have a proper justification – either it’s less than 50 volts,
it poses a greater hazard to shut down, or it’s infeasible to shut down while
completing your task, i.e., troubleshooting.
- If exposed live parts are not de-energized, the
employees must be protected from both direct and indirect contact, e.g., conductive
- Equipment that has been shut off but is not
locked out/tagged out must be treated like it is energized.
- Employees must follow appropriate lockout/tagout
procedures when de-energizing equipment.
- A qualified person (see definition above) must
verify that electric equipment is de-energized and must inspect the equipment
before it is ready to be re-energized.
- Only qualified personnel are permitted to work
on energized equipment (including voltage testing on supposedly de-energized
- If working near overhead power lines, the lines
must be de-energized and grounded or other protective measures must be used if
this isn’t possible.
- Unqualified employees working near overhead
power lines must stay at least 10 feet away from the lines (this
includes vehicles and mechanical equipment).
- Qualified employees cannot get within a few feet
on an overhead line unless they’re insulated from the line or from all
conductive objects, or unless the line is insulated from them.
- Enough lighting must be provided in enclosed
spaces containing live equipment in order for employees to work safely.
- Conductive equipment, e.g. uninsulated
screwdriver; liquids, e.g. cleaning supplies; and apparel, e.g. jewelry, metal
buttons, keychains must not be used or worn where they could contact energized
- Portable ladders must have non-conductive
siderail, e.g. fiberglass, where they contact energized equipment.
- Only qualified employees can defeat electrical
safety interlocks and only for a temporary amount of time.
- Employees must not raise or lower a piece of
electrical equipment, e.g. power drill, by its cord.
- Cords should not be secured with staples or hung
in such a way that the cord can be damaged.
- All cords must be inspected for external damage
and signs of internal damage before they are used.
- Damaged or defective equipment must be removed
from service and may not be used until it is repaired/replaced.
- If a circuit breaker trips, employees may not
reset the breaker unless it’s clear that the breaker tripped because of an
overloaded circuit. If the issue is repetitive (continues to trip, or fuses
continue to melt), the fault condition must be investigated by a qualified
- Test equipment, such as a voltmeter, must be
rated for the equipment it will be contacting and must be inspected before use.
- Employees must be provided with and must wear
appropriate personal protective equipment (PPE) based on the electrical hazards
presented (this includes arc flash protective clothing, safety glasses, an
arc-rated face shield, insulated gloves, and hearing protection as required).
- PPE must be inspected before use and tested at
certain intervals – for instance, rubber insulating gloves must be electrically
tested before their first issue and every 6 months thereafter (note: if the
gloves haven’t been used in the past 6 months, this testing requirement is
extended to 12 months after the previous test date).
- Safety signs, symbols, and tags must be used
where necessary to warn employees about electrical hazards, e.g. ‘Danger –
Shock Hazard When Cover Removed.’
- Insulated fuse-handling equipment must be used
to replace fuses when the fuse terminals are live.
There are some problems with these employee safety-based requirements
– they’ve got gaps. OSHA’s standard is old and it takes a long time to make
updates. As a result, the requirements don’t adequately address arc flash/arc
blast (not formally studied until 1993), which is a serious recognized
electrical hazard. They also don’t address having an electrical safety program,
safe work procedures for energized tasks, or arc-rated PPE. OSHA is well aware
of these gaps, so they refer us to another consensus standard out there called NFPA (National Fire Protection Association)
70E, Electrical Safety Requirements for the Workplace. NFPA 70E is a thorough
guideline that addresses electrical safety for employees. It has details on
conducting a shock and arc flash risk assessment and protecting employees
accordingly. NFPA 70E is revised every three
years, and the latest edition is from 2015. Because revisions are made every three
years, the standard recommends that electrical safety training for qualified
workers be performed every three years.
How to Keep Your Employees Safe
Compliance with OSHA regulations
is important, but it’s not the only thing that can keep your employees safe. If
there are electrical hazards present at your workplace, and/or if you have
employees that are at risk of electrical injury, it’s essential that you have a
well-rounded Electrical Safety Program that incorporates shock and arc
flash risk assessments (NFPA 70E).
Shock Risk Assessment
Conducting a risk assessment
for electric shock is fairly easy if you’re referencing the NFPA 70E standard
because it is based on voltage alone.
For example, if an employee is working on a 480 volt AC system then
he/she should wear, at a minimum, a class of rubber insulating gloves that is
rated to at least 500 volts AC (class 00), if not the next class up (class 0,
1000 volts AC).
The voltage also determines what the NFPA 70E calls
“approach boundaries”. There are two of
them – 1) Limited boundary, past which point unqualified employees are not allowed;
and 2) Restricted boundary, past which point qualified employees must be
prepared to do live work and be protected (no conductive objects allowed past
Arc Flash Risk Assessment
An arc flash risk assessment is more complicated and is typically contracted out to an engineering firm. In order to conduct the assessment, you need to know the short-circuit current and fault clearing time for each piece of equipment. Using this data, the incident energy level, i.e. heat level in calories per square centimeter (cal/cm2) and arc flash protection boundary (typically in inches) can be determined and your equipment labeled accordingly. The arc flash risk assessment essentially tells you “if something causes an arc flash/blast in this panel, this is how big it’s going to be.” These assessments shouldn’t just tell you how to protect yourself, they should also clue you in as to where you should target hazard reduction and make the equipment itself safer.
Other Program Elements
If your employees must perform live (energized) work, either
because it’s infeasible or more dangerous to shut down the equipment, then live
electrical safe work procedures should be developed. If the task is non-routine
and you don’t have a safe work procedure, then employees should fill out a live
electrical work permit before beginning the task. NFPA 70E has an example
of a live electrical work permit that can be used in such situations.
Your program should also incorporate how your facility is
going to manage contractor safety regarding electrical work, preventative
maintenance/upkeep of equipment, and other specific OSHA requirements (several
of which are included in the bulleted lists above).
Electrical Safety Tips
Whether the electrical safety requirements apply to you or
not, all companies and employees should follow these safety tips:
- Have a healthy respect for electricity, no matter
the voltage or current level. Low voltage doesn’t always mean low hazard.
- #1 Rule: when possible, work de-energized
according to proper lockout-tagout procedures. You should have a very good
justification for doing any live work.
- Assume that all wires are energized, even if
they appear to be insulated.
- Do not use electrical equipment that shocks,
smokes, smells, is damaged, or has burn marks. Repair or replace it.
- Never repair electrical cords or equipment
unless you’re qualified; and don’t repair cords with electrical tape.
- Never operate electrical equipment while
standing in water (it may hurt).
- In wet/damp locations, ensure your electrical
circuit or receptacle is equipped with a ground fault circuit interrupter
Hellman & Associates, Inc. provides Electrical
Safety/Arc Flash training for qualified employees (including refresher courses)
and electrical awareness safety training for unqualified employees. We can also
help you build/implement an Electrical Safety Program and develop safe work
procedures. Give us a call if you need specialized electrical safety training
or program development.