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Electrical hazards


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Electrical hazards

  1. 1. Presented By: K.Shamili 1702-13-886-005 Department Of Pharmaceutics Under The Guidance Of: Dr.Jagadeesh Induru M.Pharm ,M.B.A, PhD Mrs. Tripti Suxena M.Pharm 1
  2. 2. 2 Introduction Types of current Dangers of electricity to the living tissue Electric shock Conditions that effect the shock Saving the electrified person Protection against electrical hazards Electric hazard control Things to be avoided Safety measures Regular safety Inspection References
  3. 3. 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 shock The 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. 3
  4. 4. 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 4
  5. 5. 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. 5
  6. 6. 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: Shock Shock 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 heart cannot pump blood). Burning of tissue and organs Tissue and organs may be burned so badly that they haemorrhage. Death Death can result from electrocution, which is caused by electric shock. 6
  7. 7. 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. 7
  8. 8. 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 beating Effects of Electrical Current On the Human Body 8
  9. 9. 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 9
  10. 10. ❑ LOCATION ON THE BODY OF THE ELECTRICAL CONTACT An electric shock that starts at a finger and exits through the grounded elbow 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
  11. 11. 11 ❑ 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.
  12. 12. 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. 12
  13. 13. After the person who is suffering from electric shock has been removed from the source of the shock, check to see if this person is having breathing problems or is experiencing ventricular fibrillation. Artificial respiration or cardiopulmonary resuscitation should be performed 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. 13
  14. 14. 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. 14
  15. 15. 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 fail Insulation 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
  16. 16. 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 connection White 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
  17. 17. 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 equipment If 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
  18. 18. 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.18
  19. 19. Water is VERY conductive! Overloading! Missing grounding prong! 19
  20. 20. Missing outlet cover! Electrical tape is not a fix! Damaged casing! 20
  21. 21. Don’t wear metal objects Turn power off Wear appropriate clothing Don’t touch live parts Don’t install or repair electrical equipment Use qualified personnel Clean and dry leads and plugs before use Heed warning signs Use the right equipment Study the operation manual Take care of extension leads Use only approved extension lamps 21
  22. 22. 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 22
  23. 23. 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 followed Ensure 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 23
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