ELECTRICAL HAZARDS Electricity is a serious workplace hazard. Employees can be exposed to dangers such as : Electric Shock Electrocution Burns Fires Explosion
Electricity Some materials resist electricity better than others. For example : Dry wood has a high resistance to electric current, but when wet it will readily conduct electricity. The same applies to human skin. When dry it has a fairly high resistance to electric current, but when moist, there is a radical drop in its resistance.
ELECTRIC SHOCK Electric shock occurs when the body becomes part of the electric circuit. The current must enter the body at one point and leave at another.
Electrical shock can occur in one of three ways: 1.A person while in contact with the ground must come into contact with both wires of the electrical circuit. 2.A person can come into contact with one wire of an energised circuit and the ground. 3.A person can come into contact with a metallic part that has become ‘hot’ by contacting with an energised conductor.
BURNS A common shock related injury is a Burn. Electrical burns are a result of an electrical current flowing through bone and tissue. Electrical burns are one of the most serious injuries you can receive and should be given immediate attention.
PREVENTION The metal parts of electric tools and machines may become energised if there is a break in the insulation of the tool or its wiring. People are made less vulnerable to electric shock with the use of earths.
Earth wires People are made less vulnerable to electric shock with the use of earth wires. Earths use a low resistance wire that cause any unwanted current to pass directly to ground. This greatly reduces the amount of current passing through the persons body in contact with the tool or machine.
PROTECTION Insulation will protect a person from electrically energised wires and parts. Insulators can be made from glass, rubber or plastic. Before using any tools check any cables for damage such as cuts.
110 v All electrical equipment on British building sites is 110 volts. 110 volts is not enough to kill you. This therefore reduces the chance of fatalities.
WORKING SAFELY All electrical equipment should be tested at regular intervals. PAT (Portable Appliance Testing) is carried out on all portable appliances used by employees, any public appliance in public places eg schools, hotels, any Hire Equipment and any repair or service outlets. PAT testing is required under HASWA.
WORKING SAFELY Inspect before use that any leads or cords are intact and not damaged in any way. Check that the case or body of any tool is not cracked, damaged or loose in any way. Check triggers, switches or buttons work properly and do not stick or are loose.
What to do Any Electrical Hazard should be reported to your Supervisor and isolated. Only use a DRY POWDER or CARBON DIOXIDE (C02) extinguisher on an electrical fire.
FIRE SAFETY AND PROCEDURES THE FIRE TRIANGLE Fire requires three elements : HEAT HEAT FUEL FUEL OXYGEN OXYGEN
THE FIRE TRIANGLE A Fire can be prevented or extinguished by removing one of these elements. Without HEAT, a fire cannot begin. Without FUEL, a fire will stop. Without OXYGEN, a fire cannot begin, and it cannot continue.
EXTINGUISHERS Different fire extinguishers are used to fight fires by acting on one of the three elements in the fire triangle. It is important to use the right fire extinguisher on the right type of fire. Fire extinguishers are colour coded according to their contents. Another type of fire extinguisher is a Fire Blanket.
Extinguisher colours and use. WATER A water extinguisher is a red canister. Water works by taking the heat out of the burning material.
WATER USE ON USE ON PAPER TEXTILES WOOD DO NOT USE ON ANY FLAMMABLE LIQUID. LIVE ELECTRICAL EQUIPMENT.
DRY POWDER Dry powder is in a canister with a BLUE label. Works by making the flames too cool for the chemical reactions to continue. However, it does not cool the fire very well and care should be taken to make sure the fire does not flare up again.
DRY POWDER USE ON PAPER,WOOD. FLAMMABLE LIQUIDS. LIVE ELECTRICAL GASEOUS FIRES
FOAM Foam extinguishers are in a canister with a CREAM label. A foam extinguisher works by forming a blanket over the fuel of the fire. This prevents oxygen reaching the fuel.
FOAM USE ON PAPER WOOD TEXTILES FLAMMABLE LIQUIDS DO NOT USE ON LIVE ELECTRICAL EQUIPMENT
CO2 ( CARBON DIOXIDE) CO2 extinguishers are in a canister with a BLACK label. Works by removing the oxygen around the fire. Also removes the heat from the combustion zone
CARBON DIOXIDE (CO2) USE ON FLAMMABLE LIQUIDS LIVE ELECTRICAL EQUIPMENT DO NOT USE IN A CONFINED SPACE CO2 does not work well on wood, paper fires. It may not displace enough oxygen to put the fire out, causing it to re ignite.
KNOW YOUR EXTINGUISHERS USING THE WRONG TYPE OF USING THE WRONG TYPE OF FIRE EXTINGUISHER FIRE EXTINGUISHER CAN BE LIFE THREATENING CAN BE LIFE THREATENING
PROCEDURES Know where the fire assembly point is. Know where the fire extinguishers are. Make sure you don’t block any fire escape routes with tools or equipment. If you discover a large fire, raise the alarm and leave the building immediately.