1. Electrical Safety www.CareerSafeOnline.com INSTRUCTOR’S NOTES:
This presentation is designed to assist trainers conducting OSHA 10-hour General Industry outreach training for youth workers. Since youth workers are the target audience, this presentation may cover hazard identification, avoidance, and control – not standards. No attempt has been made to treat the topic exhaustively. It is essential that trainers tailor their presentations to the needs and understanding of their audience.
This presentation is not a substitute for any of the provisions of the Occupational Safety and Health Act of 1970 or for any standards issued by the U.S. Department of Labor. Mention of trade names, commercial products, or organizations does not imply endorsement by the U.S. Department of Labor.

2. Electrical Safety
Electricity is an important part of our modern world and sometimes it is easy to forget just how dangerous it can be.
Given the correct circumstances, electricity can cause serious injuries or even death. 
INSTRUCTOR’S NOTES:

3. Electrical Safety
Electrocution is the cause of 12% of all workplace deaths among young workers.
Electrocution is the third leading cause of work-related deaths among 16 and 17-year-olds.
INSTRUCTOR’S NOTES:

4. Electrical Injuries The most common types of electrical injuries are:
Electrical shock
Electrocution (death due to
electrical shock)
Burns
Falls
INSTRUCTOR’S NOTES:
There are four main types of electrical injuries are electrical shock, electrocution (death due to electrical shock), falls and burns.
Shock occurs when the body becomes part of the path through which electrons flow. The resulting effect on the body can be either direct or indirect. With a direct shock, injury or death occurs. Currents less than 30 milliamps can cause death. The indirect effect of an electrical shock might be from a fall from a ladder or other elevated work surface, or from being knocked or pulled into operating machinery.
Burns can result from touching electrical wiring or equipment that is improperly used or maintained (usually burn injuries occur to the hands). However, burns can also result from electrical explosions or fires. An electrical explosion occurs when electricity provides a source of ignition for an explosive mixture in the atmosphere, usually caused by overheated conductors or equipment or sparking at switch contacts. An electrical fire is often caused by defective or misused electrical equipment, improperly spliced wiring and overheated circuits.

5. Electrical Shock
Touching a live wire and an electrical ground will cause a shock.
INSTRUCTOR’S NOTES:
You will receive an electrical shock if a part of your body completes an electrical circuit by touching a live wire and an electrical ground.
A severe shock can cause much more damage to the body than is visible. A person may suffer internal bleeding and destruction of tissues, nerves, and muscles. Sometimes the hidden injuries caused by electrical shock result in a delayed death. Shock is often only the beginning of a chain of events. Even if the electrical current is too small to cause injury, your reaction to the shock may cause you to fall, resulting in bruises, broken bones, or even death.
If an electrocution occurs:
DO NOT touch the victim or the conductor
Shut off the current at the control box
If shutoff is not immediately available, use non-conducting material to free the victim
Call for help
If necessary and you know how, begin CPR
In dealing with electricity, never exceed your expertise

6. Electrical Shock
Touching two live wires of different voltages will cause electrical shock.
INSTRUCTOR’S NOTES:
Your body can connect the wires if you touch both of them at the same time. Current will pass through your body and you will be shocked.
You can even receive a shock when you are not in contact with an electrical ground. If you come into contact with both live wires of a 240-volt cable, you will be shocked. You can also receive a shock from electrical components that are not grounded properly. Even contact with another person who is receiving an electrical shock may cause you to be shocked.

7. Electrical Shock The severity of the shock depends on:
Path of the current through your body
Amount of current flowing
through your body
Length of time your body is in contact with the circuit
INSTRUCTOR’S NOTES:
The severity of injury from electrical shock depends on the amount of electrical current and the length of time the current passes through the body. For example, 1/10 of an ampere (amp) of electricity going through the body for just 2 seconds is enough to cause death. The amount of internal current a person can withstand and still be able to control the muscles of the arm and hand can be less than 10 milliamperes (milliamps or mA). Currents above 10 mA (1/100 of an amp) can paralyze or "freeze" muscles. When this "freezing" happens, a person is no longer able to release a tool, wire, or other object. In fact, the electrified object may be held even more tightly because the muscles are frozen, resulting in longer exposure to the shocking current. For this reason, hand-held tools that give a shock can be very dangerous. If you can't let go of the tool, current continues through your body for a longer time, which can lead to respiratory paralysis (the muscles that control breathing cannot move). You stop breathing for a period of time. People have stopped breathing when shocked with currents from voltages as low as 49 volts. Usually, it takes about 30 mA of current to cause respiratory paralysis.
A small current that passes through the trunk of the body (heart and lungs) is capable of causing severe injury or electrocution. Low voltages can be extremely dangerous because, all other factors being equal, the degree of injury increases the longer the body is in contact with the circuit. LOW VOLTAGE DOES NOT MEAN LOW HAZARD
LOW VOLTAGE DOES NOT MEAN LOW HAZARD

8. Burns
Burns are the most common injury caused by electricity. The three types of burns are:
Electrical burns
Arc burns
Thermal contact burns
INSTRUCTOR’S NOTES:
The most common shock-related, nonfatal injury is a burn. Burns caused by electricity may be of three types: electrical burns, arc burns, and thermal contact burns.
Electrical burns can result when a person touches electrical wiring or equipment that is used or maintained improperly. Typically, such burns occur on the hands. Electrical burns are one of the most serious injuries you can receive. They need to be given immediate attention.
Electrical burns can occur when you come into direct contact with electricity.

9. Burns
An arc occurs when there is a gap between conductors and current travels through the air.
Electrical burns
Arc burns
Thermal contact burns
INSTRUCTOR’S NOTES:
Arc-blasts occur when powerful, high-amperage currents arc through the air. Arcing is the luminous electrical discharge that occurs when high voltages exist across a gap between conductors and current travels through the air. This situation is often caused by equipment failure due to abuse or fatigue. Temperatures as high as 35,000°F have been reached in arc-blasts.

10. Burns
Thermal contact burns can occur when electricity ignites combustible material.
Electrical burns
Arc burns
Thermal contact burns
INSTRUCTOR’S NOTES:
Thermal burns may result if an explosion occurs when electricity ignites an explosive mixture of material in the air. This ignition can result from the buildup of combustible vapors, gasses, or dusts. Ignition can also be caused by overheated conductors or equipment that ignite flammable material or by normal arcing at switch contacts or in circuit breakers. Clothing may catch fire and a thermal burn may result from the heat of the fire.

11. Falls Another common type of electrical injury is falling.
Workers who experience a shock on elevated work surfaces such as platforms, ladders or scaffolds can fall resulting in serious injury or death.

12. Electrical Hazards
To avoid injuries, you should be aware of electrical hazards. Some of the most common electrical hazards are:
Exposed electrical parts
Overloaded circuits
Defective insulation
Improper grounding
Damaged power tools
Overhead power lines
Wet conditions
INSTRUCTOR’S NOTES:
The first step toward protecting yourself is recognizing the many hazards you face on the job. To do this, you must know which situations can place you in danger. Knowing where to look helps you to recognize hazards.
Let’s take a closer look at each of these hazards.

13. Exposed Electrical Parts
Exposed electrical parts can include:
Breaker boxes without a cover
Electrical terminals in motors, appliances, and electronic equipment
INSTRUCTOR’S NOTES:
Electrical hazards exist when wires or other electrical parts are exposed. Wires and parts can be exposed if a cover is removed from a wiring or breaker box. The overhead wires coming into a home may be exposed. Electrical terminals in motors, appliances, and electronic equipment may be exposed. Older equipment may have exposed electrical parts. If you contact exposed live electrical parts in any way, you will be shocked. You need to recognize that an exposed electrical component is a hazard.
(g) 600 Volts, nominal, or less.
(2) Guarding of live parts.
(i) Except as required or permitted elsewhere in this subpart, live parts of electric equipment operating at 50 volts or more shall be guarded against accidental contact by approved cabinets or other forms of approved enclosures, or by any of the following means:
[A] By location in a room, vault, or similar enclosure that is accessible only to qualified persons.
[B] By suitable permanent, substantial partitions or screens so arranged that only qualified persons will have access to the space within reach of the live parts. Any openings in such partitions or screens shall be so sized and located that persons are not likely to come into accidental contact with the live parts or to bring conducting objects into contact with them.
[C] By location on a suitable balcony, gallery, or platform so elevated and arranged as to exclude unqualified persons.
[D] By elevation of 8 feet or more above the floor or other working surface.
(ii) In locations where electric equipment would be exposed to physical damage, enclosures or guards shall be so arranged and of such strength as to prevent such damage.
(iii) Entrances to rooms and other guarded locations containing exposed live parts shall be marked with conspicuous warning signs forbidding unqualified persons to enter.
(g)(2)(iii)

14. Overloaded Circuits Overloading a circuit increases the potential for
fires to occur. Overload hazards exist if:
Too many devices are plugged into a circuit
The wire insulation melts
An improper overcurrent protection device is used
No overcurrent protection device is used
INSTRUCTOR’S NOTES:
Overloads in an electrical system are hazardous because they can produce heat or arcing. Wires and other components in an electrical system or circuit have a maximum amount of current they can carry safely. If too many devices are plugged into a circuit, the electrical current will heat the wires to a very high temperature which may cause a fire. If any one tool uses too much current, the wires will heat up.
If the wire insulation melts, arcing may occur and cause a fire in the area where the overload exists, even inside a wall. If the circuit breakers or fuses are too big (high current rating) for the wires they are supposed to protect, an overload in the circuit will not be detected and the current will not be shut off. A circuit with improper overcurrent protection devices – or one with no overcurrent protection devices at all – is a hazard.

15. Overloaded Circuits Overcurrent protection devices include:
Circuit breakers
Fuses
Ground fault circuit interrupters (GFCI)
INSTRUCTOR’S NOTES:
In order to prevent too much current in a circuit, a circuit breaker or fuse is placed in the circuit. If there is too much current in the circuit, the breaker "trips" and opens like a switch. If an overloaded circuit is equipped with a fuse, an internal part of the fuse melts, opening the circuit. Both breakers and fuses do the same thing: open the circuit to shut off the electrical current.
Circuit breaker - an overcurrent protection device that automatically shuts off the current in a circuit if an overload occurs.
A circuit breaker automatically “trips” and shuts off the current in a circuit if it becomes overloaded.

16. Overloaded Circuits
A fuse contains an internal part that melts and shuts off the current if there is an overload.
Circuit breakers
Fuses
Ground fault circuit interrupters
INSTRUCTOR’S NOTES:
Fuse - an overcurrent protection device that has an internal part that melts and shuts off the current in a circuit if there is an overload.

17. Overloaded Circuits
A ground fault circuit interrupter (GFCI) detects current leaking from a circuit to ground and shuts the current off.
Circuit breakers
Fuses
Ground fault circuit interrupters
INSTRUCTOR’S NOTES:
GFCI - ground fault circuit interrupter - a device that detects current leakage from a circuit to ground and shuts the current off.
GFCI's help protect you from electrical shock by continuously monitoring the circuit. However, a GFCI does not protect a person from line-to-line hazards such as touching two "hot" wires (240 volts) at the same time or touching a "hot" and neutral wire at the same time. Also be aware that instantaneous currents can be high when a GFCI is tripped. A shock may still be felt. Your reaction to the shock could cause injury, perhaps from falling.
Test GFCI's regularly by pressing the "test" button. If the circuit does not turn off, the GFCI is faulty and must be replaced.
GFCI’s compare the amount of current going into electric equipment with the amount of current returning along the circuit. If the difference exceeds 5 milliamperes (the amount of current that delivers a slight shock), the GFCI automatically shuts off the power in as little as 1/40 of a second.
Receptacle type

18. Summary
It is very important to StartSafe and StaySafe around electricity. In order to do so:
Know the hazards
Plan your work and plan for safety
Avoid wet working conditions and other dangers
Avoid overhead power lines
Use proper wiring and connectors
Use and maintain tools properly
Wear the correct PPE for the job