Electrical Risk

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

Electric Shock

Electric Shock Risk

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)

Touch Potential

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.

StepPotential (foot/footpath)

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 and step potential

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.

Arc Flash 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. 

Arc Flash Risk

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

 Arc-Flash depends on one or more of the following criteria:
·       Available short circuit current.
·       System voltage.
·       Arc gap.
·       Distance from the arc.
·       Opening time of overcurrent.
·       protective device (OCPD)
Arc Flash Risk Asseement

Arc Blast Effect:

Arc Blast

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.

Light and Sound Effects

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.