It is very important to understand your workplace and the available hazards or risks in the place. We have to ensure that our workplace is safe and personally take responsibility for keeping it safe. You might be working in developed nations like the USA, Saudi Arabia, Qatar, UK, United Arab Emirates Kuwait, or developing countries like India, Brazil, the Philippines, or any other nations. Irrespective of the country your workplace is located it's the responsibility of the employer to provide a safe working environment as per OSHA regulations and the responsibility of the employee to understand the available risk and follow the rules and apply the risk-mitigating techniques as per the international standards and regulations.
The main hazards of working
with electricity are electric shock and burns from contact with live parts. Injury From exposure to
arcing, fire from
faulty electrical equipment or installations.
- Electric shock
- Exposure to Arc-Flash
- Exposure to
Arc-Blast
- Exposure to
excessive light
Secondary
hazards may include burns, the release of toxic gases, molten metal, airborne debris
and shrapnel. Unexpected events can cause startled workers to lose their
balance and fall from ladders or jerk their muscles possibly causing whiplash
or other injuries
When personnel come in contact with energized conductors they receive a shock with Current flowing through their skin, muscles, and vital organs. The severity of the shock depends on the current’s path through the body, the current intensity, and the duration of the contact. They may only experience a mild tingling sensation or it could result in serious injury or death. As voltage levels increase, the effects of electric shock escalate. Current may also cause an erratic heartbeat known as ventricular fibrillation. If fibrillation occurs even briefly and
Goes
untreated, the effects are usually fatal.
There are
three basic pathways electric current travels through the body;
1) Touch Potential (hand/hand path)
2) Step Potential (foot/footpath)
3) Touch/Step Potential (hand/foot
path)
Touch Potential (hand/ hand path)
In a touch potential contact, current travels from one hand through the Heart and out through the other hand. Because the heart and lungs are in The path of the current, ventricular fibrillation, difficulty in breathing, unconsciousness, or death may occur.
In a step potential contact, current travels from one foot through the legs, and out of the other foot. The heart is not in the direct path of current but the leg muscles may contract, causing the victim to collapse or be momentarily paralyzed.
Touch/Step Potential (hand/footpath)
In a touch/step potential contact, current travels from
one hand, through the
Heart, down the leg, and out of the foot. The heart and
lungs are in the direct
Path of current so ventricular fibrillation, difficulty
in breathing, collapse,
Unconsciousness or death may occur.
Even though there may be no external signs from
the electrical shock, internal tissue or organ damage may have occurred. Signs
of internal damage may not surface immediately; and when it does, it may be too
late. Any person experiencing any kind of electrical shock should seek immediate
medical attention. Using the correct personal protective equipment (PPE) and
following safe work practices will minimize the risk of electrical shock hazards.
An Arc-Flash is an unexpected sudden release of heat and light energy produced by electricity traveling through air, usually caused by accidental contact between live conductors. Temperatures at the arc terminals can reach or exceed 35,000 degrees Fahrenheit (F), or four times the temperature of the sun’s surface. The air and gases surrounding the arc are instantly Heated and the conductors are vaporized causing a pressure wave called an Arc Blast. Personnel directly exposed to an Arc-Flash and Arc-Blast events are subject to third degree burns, possible blindness, shock, blast effects and hearing loss. Even relatively small arcs can cause severe injury.
The secondary effect of arcs includes toxic gases, airborne debris, and potential damage to electrical equipment, enclosures and raceways. The high temperatures of the arc and the molten and vaporized metals quickly ignite any flammable materials. While these fires may cause extensive property damage and loss of production, the hazards to personnel are even greater. The arc current can vary up to the maximum available bolted fault current. For the purpose of understanding the potential effects of an Arc-Flash, you must determine the working distance from an exposed “live” part. Most measurements or calculations are made at a working distance of 18 inches.
This distance is used because it is the approximate distance a worker’s face or
upper body torso may be away from an arc, should one occur. Some parts of a
worker may be less than 18 inches away, but other work may be performed at
greater distances. The working distance is used to determine the degree of risk
and the type of personal protection equipment necessary to protect against the
hazard. Several
groups and organizations have developed
formulas to determine the incident
energy available at various working distances
from an Arc-Flash. In all cases, the
severity of the
During an Arc-Flash, the rapidly expanding gases and heated air may cause blasts, pressure waves, or explosions rivaling that of TNT. The gases expelled from the blast also carry the products of the arc with them including droplets of molten metal similar to buckshot. For example, the high temperatures will vaporize copper, which expands at the rate of 67,000 times its mass when it changes from solid to vapor. Even large objects such as switchboard doors, bus bars, or other components can be propelled several feet at extremely high velocities.
The intense light generated by the Arc-Flash emits dangerous ultraviolet frequencies, which may cause temporary or permanent blindness unless proper protection is provided. The sound energy from blasts and pressure waves Can reach 160 dB, exceeding the sound of an airplane taking off, easily rupturing eardrums and causing permanent hearing loss. For comparison, OSHA states that decibel levels exceeding 85 dB require hearing protection
Electrical
safety hazards such as exposure to shock and Arc-Flash can also be caused by:
- Ø Worn or broken
conductor insulation.
- Ø Exposed live parts.
- Ø Loose wire
connections.
- Ø Improperly
maintained switches and circuit breakers.
- Ø Obstructed
disconnect panels.
- Ø Water or liquid
near electrical equipment.
- Ø High voltage
cables.
- Ø Static electricity.
- Ø Damaged tools and equipment.
The severity
and causes of electrical hazards are varied, but the best protection is to de-energize
equipment before working on it. No one has ever been killed or injured from an
Arc-Flash while working on de-energized equipment. If equipment cannot be
deenergized, electrical workers must be “qualified”, trained, wear
Appropriate
personal protective equipment (PPE), and follow all applicable OSHA and NFPA
standards. It is important to remember that proper selection and application of
overcurrent protective devices (OCPD) will also substantially reduce the
hazards.
The electrical risk at the workplace is a huge topic of discussion. There might be more hazards like static electricity risk, hazardous are risk, and many known or unknown risks which may not be feasible to cover in this article at the workplace which needs special attention as per the workplace nature. You can read the specific risk in our knowledge base articles for more information.
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