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Notes for Hazards of Electricity ly on (A) The electrical hazard that most people are aware of and that most safety standards address is the SHOCK hazard. prac SHOCK affects human beings in three ways: for 1) Affects Heart Function W 2) Injures body tissue o 3) Causes muscular contractions Each of these is potentially deadly. 1) An electric shock can interfere with heart function causing fibrillation. FIBRILLATION: is the rapid, irregular, and unsynchronised contraction of the muscle fibres and is very serious when occurring in the heart. A voltage a low as 50 Vac can cause fibrillation if skin resistance is low and the resulting current flows through the chest area. 2) Electric shock can also injure tissue both within the body and at the entrance and exit points. The injuries are primarily internal burns, of 3rd degree and are often more serious than burns caused by heat or fire. The full extent of internal injuries may not become apparent for weeks. 3) Muscle contraction induced by electric shock may make it impossible for the person to let go of the conductor. This can obviously prolong the shock. At about 2300V the person would be electrocuted before he managed to touch the conductor. Factors Affecting Electrical Injuries The severity of the injury sustained by a person, coming into contact with electricity, depends on several factors: 1) CURRENT, expressed in Amperes it is the amount of electricity flowing in a circuit. 2) VOLTAGE, the pressure which drives the current through the system.