EH-92-5 Electrical Safety: A Perspective on Operational Experience
ENVIRONMENT, SAFETY & HEALTH
BULLETIN
Assistant Secretary for U. S. Department of Energy
Environment, Safety & Health Washington, D.C. 20585
DOE/EH-0275 Issue No. 92-5 November 1992
ELECTRICAL SAFETY: A PERSPECTIVE ON
OPERATIONAL EXPERIENCE
Concern is growing within the Department of Energy (DOE) over a series of
events that involved electrical shock to contractor employees at DOE
facilities. Numerous deficiencies in electrical safety practices were
identified by nearly all of the 35 Tiger Team Assessments. Although DOE
is making progress in correcting electrical deficiencies at our
facilities, the continuing electrical safety incidents indicate that more
effort is needed to identify and correct root cause problems. The
following data, obtained from DOE's Safety Performance Measurement System
and Occurrence Reporting and Processing System identify the types of
incidents that are occurring within DOE. DOE and its contractor employees
are working together to strengthen DOE programs that protect the workplace
from such hazards.
Findings
More than 2,300 Occupational Safety and Health Administration (OSHA)
electrical safety findings have been documented by Tiger Team Assessments.
Each of these compliance findings involving electrical safety (Title 29
Code of Federal Regulations [CFR] 1910 Subpart S, and 29 CFR 1926 Subpart
K) represents a deficiency in, or the lack of, a requirement "necessary
for the practical safeguarding of employees in their workplaces."
Direct Contact Injuries -
Shocks and Burns
A number of DOE and contractor employees have been injured as a result of
electrical shocks. Approximately 130 DOE or contractor personnel reported
shocks or burns due to contact with electricity in the workplace from
January of 1983 to October 28, 1992 (91 shocks, 39 burns). Although
averaging only 13 direct-contact reports per year, the possible
consequences of these electrical contacts must be kept in mind.
Electrocution killed four people during the 9 1/2 years; a fifth death may
have been the indirect result of an electrical shock. Three additional
deaths that were related to electrical work, but were not the result of
direct contact, will be discussed later.
The four electrocution deaths resulted from direct contact with high
voltage circuits. Three of the four victims were Power Administration
electricians; the fourth was an electrician at a fuel processing plant.
All but one of the victims were aware that they were working on energized
circuits. A fifth death resulted from a fall from an 85-foot high
transmission line tower. It is believed that the fall was a result of the
lineman coming in contact with an energized transmission line.
General categories of causes found in the shock and burn reports include:
o Contact with faulty (shorted) equipment (e.g., plugs, power tools,
and welders).
o Improperly wired equipment.
o Failure to implement lockout/tagout procedures and/or use adequate
protective equipment.
o Inattentiveness and carelessness, including:
- use of uninsulated tools
- use of wrong instrument/meters/tools
- failure to pre-verify volt/amp meter operation
- allowing tools to slip onto live circuits
- wearing jewelry (e.g., rings, watches, bracelets) while
working on live circuits.
o Manufacturers' defects and aging equipment.
o Inadequate procedures governing excavating and concrete
cutting/drilling.
o Failure to recognize the dangers of large capacitors.
Over 1,200 lost work days (LWDs) were the result of shocks, while
electrical burns accounted for nearly 300 LWDs. The severity of the shock
and burn injuries correlates with the amount of voltage encountered; the
higher the voltage the greater the consequences. It should be noted that
a number of the injuries reported occurred, not as a consequence of the
shock itself, but as a result of a fall after experiencing the shock.
As expected, workers in occupations most at risk from electrical shock and
burns are electricians and technicians. This is due to the nature of
their work (e.g., high voltage exposure, troubleshooting, and experimental
designs). DOE electricians and technicians have experienced over 50
percent of the reported shocks and burns. Employees in other occupations,
such as mechanics/repairers, welders, laborers/helpers, machinists, and
those that use portable electric tools, are also more at risk than might
be expected. In addition, personnel in occupations that require standing
in water when performing their tasks (e.g., firefighters, janitors) tend
to experience more shocks than do others.
Indirect Hazards - Electrically
Initiated Fires and Explosions
Approximately 97 fires or explosions either caused by or involving
electrical energy have been reported for the time period evaluated. Most
of these events did not result in injury or death; however, one death and
many injuries did occur. Electrically initiated fires and explosions
accounted for losses totaling millions of dollars, as well as worker
injuries. One event, alone, resulted in reported equipment damage of
$3,465,000.
General categories of causes found in the fire and explosions reports
include:
o Failure to include appropriate equipment in Preventative Maintenance
(PM) programs.
o Failure to have an electrical safety program and/or implement
established principles.
o Lack of knowledge by key individuals of the location of critical
shut-off breakers and switches.
o Unattended energized equipment and appliances.
o Equipment age.
o Improperly sized overload devices/no lightning arrestors or voltage
spike suppressor circuits.
o Inadequately trained and qualified high voltage electrical workers.
o Failure to develop work packages or require safe work/hazardous work
permits for tasks involving energized high voltage circuits.
o Failure to fully implement lockout/tagout procedures.
Failure to implement lockout/tagout procedures resulted in the death of
one worker and injury to another when an unlocked/untagged electrical
solenoid valve was inadvertently opened, allowing natural gas to be
released into the work area which subsequently ignited and exploded.
Those most at risk from electrically initiated fires and explosion are the
workers in the immediate area (i.e., electricians, technicians, mechanics,
etc.). However, fires that spread (and larger explosions) have the
potential to affect others as well, including the firefighters charged
with extinguishing the fires and the workers required to cleanup or return
the system to an operable condition.
Other Hazards of Electrical Work
Two deaths involving electrical workers did not result from either direct
electrical contact or a fire or explosion. These deaths were the result
of 1) falling while removing old conduit from a building being
decommissioned and 2) being crushed by a tree being felled near a power
line. Although neither involved electrical safety issues per se,
additional "general worker training" might have reduced the likelihood of
these and other similar incidents.
Recommendations
An excellent overview of electrical safety requirements can be found in 29
CFR Parts 1910.331 - 1910.335, "Safety-Related Work Practices." These
five parts contain information on "qualified" vs. "unqualified" persons,
training requirements, work practice selection, use of electrical
equipment, and safeguards for personnel protection. If these requirements
had been followed completely by each applicable DOE organization or
contractor, few, if any, of the 130 shock and burn injuries or deaths
would have occurred.
Shock and Burn Recommendations
o Review programs for the inspection and/or repair of portable
electrical equipment for completeness and effectiveness.
o Review policies concerning work permits on "live" circuits with a
goal of reducing the frequency of such work.
o Emphasize electrical worker training in certain areas such as the
following:
- Lockout/tagout practices
- Use of protective equipment
- Use of insulated tools
- Minimum approach distances
- Meter selection/testing/use
- Electrical rescue/CPR
- Potential dangers involving metal tapes/"fish" tapes
- Include a pre-task review of the following for supervision of
selected electrical work.
- Goals of the task
- Task methodology (live vs. lockout/tagout)
- Qualifications of assigned personnel
- Proper instrumentation/tools
- Adequate protective equipment and usage
- Methods of preventing a fall should a shock occur
o Perform an inventory of energized electrical circuits with a goal of
disconnecting unused circuits from the source and removing the
wiring.
Fire and Explosion
Recommendations
o Review electrical preventative maintenance programs to ensure all
necessary equipment is included (e.g. connections).
o Identify old equipment and develop a program/schedule to replace the
identified equipment (e.g. transformers, large capacitors,
ballasts).
o Know locations of critical shut-off and kill switches, and ensure
that they are clearly identified.
o Check trailers and modular buildings for electrical panel quality
and size, appliance loads, loose connectors, and faulty electrical
heaters.
o Develop a program to ensure that all nonessential unattended
appliances are turned off.
o Control all high voltage tasks with a work package that includes a
hazardous/safe work permit.
o Protect deluge and sprinkler systems over switchgear, transformers,
or other high voltage electrical equipment from accidental
activation (e.g., manual control).
o Review the adequacy of the current number of lightning arrestors
and/or voltage spike suppression circuits.
o Make fire extinguishers available at remote job sites and in all DOE
vehicles.
General Recommendations
Employees should be provided training that covers information regarding
electrical risks such as inadequate grounding and reverse polarity and
likely electric shock producing equipment, including extension cords,
plugs, and portable power tools. The dangers of energized and unattended
appliances should be stressed in this training, as well as the theory
behind lockout and tagout procedures. Employees working with electricity
should also be informed on how to recognize electric shock victims, safe
methods of rescue, and cardio-pulmonary resuscitation.
DOE Electrical Safety Task Group
At the direction of the Under Secretary, the Assistant Secretary for
Environment, Safety and Health established a task group to immediately
review electrical safety programs and practices across the DOE complex.
The task group, led by EH with representatives from the Offices of Defense
Programs, Environmental Restoration and Waste Management, Energy Research,
and Nuclear Energy, will identify measures to improve and ensure
electrical safety of DOE and contractor employees. A status report and
preliminary findings from the group will be provided to the Under
Secretary by November 30, 1992.
This Bulletin is one in a series of publications issued by EH to share
occupational safety information throughout the DOE complex. To be added
to the Distribution List or to obtain copies of the publication, call
(615)576-3482. For additional information regarding the publications,
call Barbara Bowers, Safety Performance Indicator Division, Office of
Environment, Safety and Health, U. S. Department of Energy, Washington, DC
20585, (301)903-3016.