Electricity travels in closed circuits. Shock occurs when the body becomes a part of an electric circuit. Electric shock can cause direct injuries such as electrical burns, arc burns, and thermal contact burns and indirect or secondary injuries. Involuntary muscle reaction from the electric shock can cause bruises, bone fractures, and even death resulting from collisions or falls. 

Shock occurs when a person in contact with the ground comes in contact with any of the following:

• Both wires of the electric circuit.
• One wire of the energized circuit and the ground.
• A metallic part that has become energized by being in contact with an energized wire.

The severity of the shock received when a person becomes a part of an electric circuit is affected by three primary factors:

• The amount of current flowing through the body.
• The path of the current through the body.
• The length of time the body is in the circuit.

Other factors that may affect the severity of shock are the frequency of the current, the phase of the heart cycle when shock occurs, and the general health of the person prior to shock. 

Effects of Shock

Low voltage does not mean low hazard.

The effects of an electrical shock can range from a barely perceptible tingle to immediate cardiac arrest. Although there are no absolute limits or even known values that show the exact injury from any given amperage, the table below shows the general relationship between the degree of injury and the amount of amperage for a 60-cycle hand-to-foot path of one second's duration of shock.

Effects of Electric Currents in the Body

A difference of less than 100 milliamperes exists between a current that is barely perceptible and one that can kill. 

Muscular contraction caused by stimulation may not allow the victim to free himself/herself from the circuit, and the increased duration of exposure increases the dangers to the shock victim. For example, a current of 100 milliamperes for 3 seconds is equivalent to a current of 900 milliamperes applied for 0.03 seconds in causing fibrillation. The so-called low voltages can be extremely dangerous because, all other factors being equal, the degree of injury is proportional to the length of time the body is in the circuit. Simply put, low voltage does not mean low hazard.

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First Aid For Electrical Injuries

In the event of an accident involving electricity, if the individual is down or unconscious, or not breathing: CALL 911 immediately. 

If an individual must be physically removed from an electrical source, it is always best to eliminate the power source first (i.e., switch off the circuit breaker). However, if time or circumstance do not allow this option, use a nonconductive item such as a dry board. Failure to think and react properly could make you an additional victim.

If the individual is not breathing and you have been trained in CPR, have someone call 911 and begin CPR IMMEDIATELY!

Report all electrical accidents, injuries, or near misses to Safety and Risk Services. 

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Common Electrical Hazards and Preventative Steps

Many common electrical hazards can be easily identified before a serious problem exists. Read and follow all equipment operating instructions for proper use. Ask yourself, "Do I have the skills, knowledge, tools, and experience to do this work safely?"

Common signs of an electrical problem include: 

• Flickering lights
• Warm switches or receptacles
• Burning odors
• Sparking sounds when cords are moved
• Loose connections
• Frayed, cracked, or broken wires

If you notice any of these problems, have a qualified electrician address the issue immediately.

Do not attempt electrical repairs. Electrical repairs can only be made by a qualified person typically from Campus Planning and Facilities Services (CPFM). Qualified individuals must receive training in safety related work practices and procedures, be able to recognize specific hazards associated with electrical energy, and be trained to understand the relationship between electrical hazards and possible injury. Fixed wiring may only be repaired or modified by CPFM.

All electrical devices fabricated for experimental purposes must meet state and university construction and grounding requirements. Extension cords, power strips, and other purchased electrical equipment must be Underwriters Laboratories (UL) listed.

Remove all jewelry before working with electricity. This includes rings, watches, bracelets, and necklaces.

Determine appropriate personal protective equipment (PPE) based on potential hazards present. Before use, inspect safety glasses and gloves for signs of wear and tear, and other damage.

Use insulated tools and testing equipment to work on electrical equipment. Use power tools that are double-insulated or that have Ground Fault Circuit Interrupters protecting the circuit. Do not use aluminum ladders while working with electricity; choose either wood or fiberglass.

Do not work on energized circuits. The accidental or unexpected starting of electrical equipment can cause severe injury or death. Before any inspections or repairs are made, the current must be turned off at the switch box and the switch padlocked or tagged out in the off position. At the same time, the switch or controls of the machine or the other equipment being locked out of service should be securely tagged to show which equipment or circuits are being worked on. Test the equipment to make sure there is no residual energy before attempting to work on the circuit. Employees must follow lock-out/tag-out procedures.

Cords and Power Strips

If you need additional power supply, the best solution is to have additional outlets installed by Facilities Services. Do not use extension cords or power strips ("power taps") as a substitute for permanent wiring.

Extension cords and power strips may be used for experimental or developmental purposes on a temporary basis only. Extension cords can only be used for portable tools or equipment and must be unplugged after use. 

Do not use extension cords for fixed equipment such as computers, refrigerators/freezers, etc. Use a power strip in these cases. In general, the use of power strips is preferred over use of extension cords.

Power strips must have a built-in overload protection (circuit breaker) and must not be connected to another power strip or extension cord (commonly referred to as daisy chained or piggy-backed). Extension cords and power strips are not a substitute for permanent wiring. 

Avoid plugging power strips into extension cords or extension cords into power strips. 

Ensure any power strips or extension cords are listed by a third-party testing laboratory, such as Underwriters Laboratory (UL). Make sure the extension cord thickness is at least as big as the electrical cord for the tool.

Inspect all electrical and extension cords for wear and tear. Pay particular attention near the plug and where the cord connects to the piece of equipment. If you discover a frayed electrical cord, contact your Facility or Building Manager for assistance. Do not use equipment having worn or damaged power cords, plugs, switches, receptacles, or cracked casings. Running electrical cords under doors or rugs, through windows, or through holes in walls is a common cause of frayed or damaged cords and plugs.

Do not use 2-prong ungrounded electrical devices. All department-purchased electrical equipment must be 3-prong grounded with very limited exceptions.

Housekeeping Considerations for Electrical Safety

• Never store flammable liquids near electrical equipment, even temporarily.
• Keep work areas clean and dry. Cluttered work areas and benches invite accidents and injuries.
• Tape down or use cable ramps to cover any cords that cross walkways, to minimize tripping risk.
• Good housekeeping and a well-planned layout of temporary wiring will reduce the dangers of fire, shock, and tripping hazards.

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Risk Mitigation

Access to electrical panels must be unobstructed. OSHA requires a minimum clearance space of 30" wide, 36" deep, and 72" from the floor for electrical panel access. Contact your department's building manage or CPFM for assistance.

Avoid operating or working with electrical equipment in a wet or damp environment. If you must work in a wet or damp environment, be sure your outlets or circuit breakers are Ground Fault Circuit Interrupter (GFCI) protected. Temporary GFCI plug adapters can also be used but are not a substitute for GFCI outlets or circuit breakers.

Circuit Protection Devices

Fuses, circuit breakers, and Ground-Fault Circuit Interrupters are three well-known examples of circuit protection devices.

Fuses and circuit breakers are devices that are placed in circuits to automatically break the circuit when the amount of the current flow becomes excessive and therefore unsafe. Fuses are designed to melt when too much current flows through them. Circuit breakers are designed to open the circuit by electro-mechanical means.

Fuses and circuit breakers are intended primarily for the protection of conductors and equipment. They prevent overheating of wires and components that might otherwise create hazards for operators.

The Ground Fault Circuit Interrupter (GFCI) is designed to shut off electric power within as little as 1/40 of a second, protecting the person, not just the equipment. It works by comparing the amount of current going to an electric device against the amount of current returning from the device along the circuit conductors. A fixed or portable GFCI should be used in high-risk areas such as wet locations and construction sites.

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Emergency Procedures

Hazardous Waste Management 

Dispose of chemicals and gels as hazardous waste. Collect in a non-leaking container labeled with a hazardous waste tag. Request pickup of hazardous waste using the EHS online system.

Non-Hazardous Waste Management 

Some gels may be considered non-hazardous and may be treated as such. Contact the EHS Hazardous Materials team for more information. 

References 

Cornell University. 16.1 Electrical Safety. Environment, Health and Safety. (accessed 2025-06-03). 

Occupational Health and Safety Administration. Design Safety Standards for Electrical Systems; OSHA 29 CFR 1910.303. 2008.