electrical hazards and their preventions

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Presented By: K.Shamili 1702-13-886-005 Department Of Pharmaceutics Under The Guidance Of: Dr.Jagadeesh Induru M.Pharm ,M.B.A, PhD 1

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Page 1: Electrical hazards and their preventions

Presented By:K.Shamili

1702-13-886-005Department Of Pharmaceutics

Under The Guidance Of:Dr.Jagadeesh Induru M.Pharm ,M.B.A, PhD

Mrs. Tripti Suxena M.Pharm

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Page 2: Electrical hazards and their preventions

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IntroductionTypes of currentDangers of electricity to the living tissueElectric shockConditions that effect the shockSaving the electrified personProtection against electrical hazardsElectric hazard controlThings to be avoidedSafety measuresRegular safety InspectionReferences

Page 3: Electrical hazards and their preventions

An electrical hazard can be defined as- a dangerous condition where a worker could make electrical contact with energized equipment or a conductor, and from which the person may sustain an injury from shockThe law requires safe work practices. Under the Occupational Health and Safety Act and Regulations for Construction Projects, employers, supervisors, and workers each have legal responsibilities to ensure that work is being carried out in a safe manner.

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Page 4: Electrical hazards and their preventions

Electrical hazards are caused by❑ The improper use of machinery or apparatus❑ The improper use of electrical outlets❑ The improper use of electrical equipment, such as cables and power cords❑ The improper maintenance of apparatus, outlets, and electrical equipment

Basically, electrical hazards can be categorized into three types. The first and most commonly recognized hazard is electrical shock. The second type of hazard is electrical burns and the third is the effects of blasts which include pressure impact, flying particles from vaporized conductors

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Page 5: Electrical hazards and their preventions

Both alternating current (AC) and direct current (DC) can produce injury to living tissue and can destroy equipment. However, the AC (60 Hz and 120 V) that electric companies supply to most electrical outlets disturbs human nerve impulses more readily than DC of the same voltage or AC at other frequencies do because human nerve impulses resonate at approximately 60 Hz. In addition, the DC circuits often used in classroom experiments are relatively harmless. Yet, DC can still be dangerous, and burn hazards are created in many common uses of DC. So, all circuits should be treated cautiously.

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Page 6: Electrical hazards and their preventions

Electrical hazards can burn equipment and cause a fire. These hazards can also cause serious injuries. Specifically, current passing through a body may produce one or more of the following symptoms:ShockShock should not be confused with electric shock. Shock is an excitation or disturbance of the normal function of nerves or muscles.

Involuntary muscle reaction A person who experiences an electric shock may not be able to control the muscles, such as the heart, may operate abnormally.

Muscle paralysis An electric shock may prevent muscles from moving (for example, arm muscles cannot flex) or operating (for example, the heartcannot pump blood).

Burning of tissue and organsTissue and organs may be burned so badly that they haemorrhage.

DeathDeath can result from electrocution, which is caused by electric shock.

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Page 7: Electrical hazards and their preventions

Electric shock occurs when the body becomes part of an electrical circuit. Shocks can happen in three ways.• A person may come in contact with both conductors in a circuit.• A person may provide a path between an ungrounded conductor and the ground.• A person may provide a path between the ground and a conducting material that is in contact with an ungrounded conductor.An electric shock can injure you in either or both of the following.• A severe shock can stop the heart or the breathing muscles, or both.• The heating effects of the current can cause severe burns, especially at points where the electricity enters and leaves the body.

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Page 8: Electrical hazards and their preventions

Current in milli amperes

Effects

1 or less No sensation; probably not noticed

1 to 3 Mild sensation not painful

3 to 10 Painful shock.

10 to 30 Muscular control could be lost or muscle clamping

30 to 75 Respiratory paralysis

75mA to 4 amps Ventricular Fibrillation

Over 4 amps Tissue begins to burns. Heart muscles clamp andheart stops beatingEffects of Electrical Current On the Human Body

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Page 9: Electrical hazards and their preventions

CURRENT PATH THROUGH THE BODY Electric shocks are less severe if the current path does not include vital organs.

LENGTH OF TIME THE ELECTRIC SHOCK ACTS ON THE BODY The duration of the electric shock effects the extent of injury the longer the duration of the electric shock on the body, the greater risk of severe injury. In addition, the electric shock can influence the duration of exposure if a victim cannot let go of the conductor of electricity that is causing the electric shock because of loss of voluntary muscle control

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Page 10: Electrical hazards and their preventions

❑ LOCATION ON THE BODY OF THE ELECTRICAL CONTACT

An electric shock that starts at a finger and exits through the groundedelbow on the same arm will do less damage than an electric shock that starts at a finger and exits through the victim’s grounded feet.

The latter scenario is more dangerous because more tissue is affected and the path of current is closer tointernal organs.

Current can burn vital organs even if the current does not pass through those vital organs.

This type of damage may occur externally because of arcing or thermal contact (a vital organ is near tissue that is experiencing electric shock). 10

Page 11: Electrical hazards and their preventions

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❑ SKIN RESISTANCE The resistance of the body greatly affects the severity

of the electric shock. Human tissue has very low resistance because the

cellular fluid in tissue is a good conductor of electricity. However, dry skin has very high resistance where as

Resistance of wet skin is low. Skin resistance is even lower than the resistance of

wet skin if a cut or deep abrasion is present. The exposure of moist and deeper skin layers

increases the severity of injury that results from the electric shock.

Page 12: Electrical hazards and their preventions

If someone is electrified , call for emergency personnel.

Then, remove the person from contact with the energized conductor.

Do not try to touch the person or you may be electrified as well.

You can turn off the power of the device that is causing the electric shock if this can be done safely (for example, turning off the circuit breaker for the outlet in which the device is plugged).

Or you can obtain an insulator, such as a wooden meter stick, and break the contact between the person who is being electrified and the energized conductor.

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Page 13: Electrical hazards and their preventions

After the person who is suffering from electric shock has beenremoved from the source of the shock, check to see if this person ishaving breathing problems or is experiencing ventricular fibrillation.

Artificial respiration or cardiopulmonary resuscitation should beperformed on the person who experienced electric shock, if necessary.

Also, use blankets to keep the person warm.

Although a person who is electrified may appear unharmed, call emergency personnel because this person may have suffered internal injuries, such as burns to organs during the electric shock.

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Page 14: Electrical hazards and their preventions

Most electrical accidents result from one of the following three factors:• unsafe equipment or installation,• unsafe environment, or• unsafe work practices.Some ways to prevent these accidents are through the use of insulation, guarding, grounding, electrical protective devices, and safe work practices.

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Page 15: Electrical hazards and their preventions

Insulators such as glass, mica, rubber, or plastic used to coat metals and other conductors help stop or reduce the flow of electrical current. This helps prevent shock, fires, and short circuits. To be effective, the insulation must be suitable for the voltage used and conditions such as temperature and other environmental factors like moisture, oil, gasoline, corrosive fumes, or other substances that could cause the insulator to failInsulation on conductors is often colour coded. Insulated equipment grounding conductors usually are either solid green or green with yellow stripes. Insulation covering grounded conductors is generally white or gray. Ungrounded conductors, or “hot wires,” often are black or red, although they may be any colour other than green, white, or gray. 15

Page 16: Electrical hazards and their preventions

Grounding a tool or electrical system means intentionally creating a low resistance path that connects to the earth.

This prevents the buildup of voltages that could cause an electrical accident.

Grounding is normally a secondary protective measure to protect against electric shock. It does not guarantee that you won’t get a shock or be injured or killed by an electrical current.

A three pronged cord offers a grounding connectionWhite wire (neutral or common wire), returns the power. Black wire (hot wire), is connected to the switch and fuse and carries the power.Green (or ground wire). Three wires for each cord and terminal. 16

Page 17: Electrical hazards and their preventions

DO NOT use extension cords as permanent wiring. They may not be able to carry the load. However, if it is necessary to use an extension cord, never run it across walkways

Wall receptacles should be designed and installed so that no current-carrying parts will be exposed

Replace or repair electrical appliances that over heated, sparked, shorted out, smoked or have damaged cords or cracked equipmentIf wires are exposed, they may cause a shock

to a worker comes into contact with them. Cords should not be hung on nails, run over

or wrapped around objects, knotted or twisted. This may break the wire or insulation.

Short circuits are usually caused by bare wires touching due to breakdown of insulation.

Electrical tape or any other kind of tape is not adequate! 17

Page 18: Electrical hazards and their preventions

Pull the plug not the cord. Pulling the cord could break a wire, causing a short circuit.

Plug your microwave or any other large appliances into an outlet that is not shared with other appliances.

Do not overload circuits as this may cause the wires to heat and ignite insulation or other combustibles

Keep office equipment properly cleaned and maintained.

Ensure lamps are free from contact with flammable material.

Be aware of the odor of burning plastic or wire.

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Page 19: Electrical hazards and their preventions

Water is VERY conductive! Overloading!

Missing grounding prong! 19

Page 20: Electrical hazards and their preventions

Missing outlet cover!

Electrical tape is not a fix! Damaged casing!20

Page 21: Electrical hazards and their preventions

Don’t wear metal objectsTurn power offWear appropriate clothingDon’t touch live partsDon’t install or repair electrical equipment Use qualified personnelClean and dry leads and plugs before useHeed warning signsUse the right equipmentStudy the operation manualTake care of extension leadsUse only approved extension lamps

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Page 22: Electrical hazards and their preventions

Electrical equipment should be checked each time before use for defects

If not tagged or the tag is out of date then report it and place it out of service

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Page 23: Electrical hazards and their preventions

The key messages are…

The risk of electric shock from correctly installed and maintained power sources is negligible, provided that sensible precautions are taken by the operator and correct work procedures are followedEnsure that the right person is carrying out electrical work Electricity is essential but, improperly

used, it can be DEADLY!!!!!

TO STAY ALIVE, YOU HAVE TO STAY ALERT

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Page 24: Electrical hazards and their preventions

http://www.ihsa.ca/resources/health_safety_manual/pdfs/hazards/

Electricity.pdf

https://www.osha.gov/Publications/3075.html

go.hrw.com/resources/go_sc/gen/HS2LMR07.PDF

https://www.osha.gov/dte/grant_materials/.../

electrical_english_r6.pdf

https://www.lanl.gov/.../electrical/.../

elec_hazard_awareness_study_guide...

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Page 25: Electrical hazards and their preventions

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