Fire, Electrical, and Mechanical Safety Practices (PDF)

# Safety Practices - Group 2 ## Fire Safety - Is the set of practices intended to eliminate the risk of starting a fire. - Also intended to reduce the destruction caused by fire such as life and assets. - Fire safety includes: ### Fire Prevention - Is the process of preventing the occurrence of un...

# Safety Practices - Group 2 ## Fire Safety - Is the set of practices intended to eliminate the risk of starting a fire. - Also intended to reduce the destruction caused by fire such as life and assets. - Fire safety includes: ### Fire Prevention - Is the process of preventing the occurrence of uncontrolled and destructive fire, or the likelihood of destructive fire. ### Fire Suppression - Refers to the extinguishing of unwanted or uncontrolled destructive fire. - May also mean the mitigation or reduction of the effect of destructive fire. ### Fire **Use and Advantages:** - To light the surroundings at night. - For cooking and preservation of food. - To melt ores and extract pure precious metals. - Helps us make steam for electrical power plants, transportation and manufacturing plants. **Disadvantages:** - Many people are left homeless due to fire caused by unattended lit candles or stoves. - Many workers die and properties burn to ashes because of hot work malpractices in industrial plants. ### Fire Emergency Preparedness - Refers to any action that will prepare people in the eventuality of fire emergencies. - Emergency fire drills and training on putting out fires are some of fire emergency preparedness programs. ### Basic Elements of Fire or Fire Triangle - **Fuel:** Any materials which may be solid, liquid or gas that may burn are classified as fuel. The term fuel is generally limited to those substances that burn readily in air or oxygen, emitting large quantities of heat. - **Oxygen:** In combustion, air chemically combines with the hydrogen and carbon in the fuel to form water and carbon dioxide, releasing heat in the process. - **Heat:** Refers to the energy necessary to raise the temperature of a material to its ignition temperature. ### Sources of Heat - **Electricity:** When an electrical current passes through an electrical wire, the conductor becomes hot. - **Smoking:** Lighting cigarette butts can ignite flammable and combustible materials when not disposed of properly. - **Friction:** Metal to metal contacts produce heat; a fire that was caused by friction can be prevented by conducting a regular schedule of inspection. - **Cutting and Welding:** Sparks, arcs and hot metal are byproducts of welding operations. They can cause fire if they land on flammable materials. - **Spontaneous Ignition:** Spontaneous ignition is caused by oily waste and rubbish, deposits in dryers and flues, and by materials susceptible to heating. Industrial waste can also cause ignition. - **Chemical Action:** Chemicals reacting with other materials and the decomposition of unstable chemicals can start a fire. ### Classes of Fire - **Class A Fires:** Fires that involve ordinary combustible fuels, for example: wood, paper, plastic and rubber. - **Class B Fires:** Fires that consume flammable or combustible liquids or gases. For example: gasoline, diesel, alcohol, paints, thinner, grease and LPG. - **Class C Fires:** Electrical fires that involve potentially energized electrical equipment. For example: electrical motors, electric fans, air conditioning units, computers, etc. - **Class D Fires:** Fires that involve combustible metals, especially alkali metals. For example: magnesium, sodium, titanium, lithium, etc. - **Class E Fires (UK standard):** Fires that involve materials found in Class A and B fires, but also include electrical appliances, wiring or other electrically energized objects. - **Class K Fires:** "Kitchen fires" that involve combustible vegetables or animal non-saturated cooking fats in commercial cooking equipment. ## Fire Extinguisher - A handheld active fire protection device usually filled with a dry or wet chemical used to extinguish or control small fires. ### Types of Fire Extinguisher 1. **Water Fire Extinguisher:** Stop the fire by taking away the heat element of the fire triangle. Suitable for Class A fires only. 2. **Carbon Dioxide Fire Extinguisher:** Destroys fire by taking away the oxygen element of the fire triangle and also removing the heat with a very cold discharge. 3. **Dry Chemical Fire Extinguisher:** Extinguish the fire primarily by interrupting the chemical reaction of the fire triangle. 4. **Wet Chemical Fire Extinguisher:** A new agent that extinguishes the fire by removing the heat of the fire triangle and prevents re-ignition by creating a barrier between the oxygen and fuel elements. 5. **Dry Powder Fire Exinguisher:** Are similar to dry chemical except that they extinguish the fire by separating the fuel from the oxygen element or by removing the heat element of the fire triangle. 6. **Aqua Film Forming Foam Fire Extinguisher:** Uses foam agent intended to be used for Class A and B fires suppression. Its role is to cool the fire and to coat the fuel, preventing its contact with oxygen, resulting in suppression and combustion. 7. **Halogenated or Clean Agent Fire Extinguisher:** Includes the halon agents as well as newer and less ozone depleting halocarbon agents. They extinguish the fire by interrupting the chemical reaction of the fire triangle. ## Proper Use of Fire Extinguisher - **Pull the Pin:** This will allow you to discharge the extinguisher. - **Aim the Nozzle:** If you aim at the flames it will fly right through and do no good. You want to hit the fuel. - **Squeeze the Handle:** This depresses a button to release the pressurized extinguishing agent in the extinguisher. - **Sweep from Side to Side:** Until the fire is completely out. Start using the extinguisher from a safe distance away, then move toward the fire. Once the fire is out, keep an eye on the area in case it re-ignites. # Electrical Safety ## What is Electricity? - **Electricity is the interaction of electric charges**. - Electric charges are a fundamental property of protons and electrons which make up every atom. - Positive and negative charges are two types of electric charges. - Protons possess positive charge, whereas electrons carry a negative charge. ## Electrical Safety - Approved procedures that eliminate accidents by electricity, which can cause damage to health, lives and properties. ## Electrical Hazards - Anything that has the potential to result in electrical accidents that will lead to injury, fire and explosion. ## Electrical Terms - **Circuit:** A complete path for which electric current could flow. - **Current:** Flowing electrons through conductive materials. It can be measured in amperes. - **Voltage:** The measurement of the difference in the potential of a power source. Its unit is Volts. - **Conductor:** Materials that allow the flow of electrons through them. - **Insulator:** Materials that resist the flow of electrons through them. - **Lead:** The component or portion of a circuit that consumes electric power. - **Ground:** The flow of electrons from the source to the source of the earth. - **Electric Arc:** A type of continuous electric discharge that produces intense light and heat, formed between two electrodes in a gas at low pressure or in open air. ## The Dangers of Electricity - **Electric Shock and Electrocution:** A physical injury caused by an accidental flow of electricity to the body. It can cause muscle contraction, lung paralysis, ventricular fibrillation, heart paralysis and severe burns. - **Fires:** Electricity can produce enough heat or sparks that ignite combustible materials, resulting in fire. - **Explosions:** Electricity can produce enough heat or sparks that ignite combustible materials, resulting in explosions. - **Arc Flash:** Refers to the extremely high-temperature discharge that is produced by an electrical fault. - **Arc Blast:** The high pressure sound wave caused by a sudden arc fault. - **Burn:** An injury to the skin or other organic tissue primarily caused by heat or due to radiation, radioactivity, electricity, friction or contact with chemicals. - **Fall:** A sudden and unanticipated descent in space given by gravity. Shock and loss of consciousness are main causes of falls related to electrical hazards. ## Electrical Related Injuries - **Primary Injuries:** Electrocution, burns. - **Secondary Injuries:** Broken bones, laceration, death. ## Controls of Electrical Hazards 1. **Grounding:** Metalwork forming part of an electrical installation or apparatus, such as cable armouring, conduit, metal enclosures or switchgear, and frames and metalwork of motors and transformers, should be adequately bonded to a suitable electrode connection with earth. 2. **Insulations:** The principle of insulation is used when work has to be carried out at or near non-insulated live parts. Work on non-insulated parts is carried out by using protective devices such as insulating stands, mats or screens, or rubber insulating gloves to protect workers from electric shock. 3. **Safe Guarding:** Safeguarding such as covers, electrical boxes and enclosures will prevent workers from being in contact with energized electrical wiring and conduits. These safeguards also isolate the electrical conduits, contain arcs, and help to prevent igniting combustible materials located nearby. 4. **Fuse/Circuit Breakers:** A fuse is a strip of metal that melts at a predetermined value of current flow, cutting off that circuit. A circuit breaker is an automatically operated electrical switch that protects an electrical circuit from damage caused by overload or short circuit. 5. **Use of Ground Fault Current Interrupter (GFCI):** GFCI's work by comparing the amount of current going to and returning from equipment along the circuit conductors. GFCI is designed to save lives of the workers especially working with power hand tools. ## Administrative Controls - **Precautions Taken When Working:** The electricity supply should first be switched off and locked to make sure that the circuits or apparatus being worked on is effectively electrically isolated and cannot become live. - **Inspection and Maintenance of Equipment:** Should include the checking of the continuity of grounding systems, the insulation of every electrical cord, and electrical boxes. The computation of loads connected to electrical circuits must also be monitored to eliminate overloading. - **Complete Fire Fighting Equipment:** Portable fire extinguishers such as Dry Chemical and Carbon Dioxide should be available. The company must train personnel who can fight electrical fires, making sure they know how to use fire extinguishers and have adequate emergency preparedness knowledge. This includes evacuation and first aid. - **Proper Use of Extension Cords:** Extension cords should be inspected regularly for damages. Do not use them in wet areas or on hot surfaces. Use the correct wire gauge and cord length for their intended use. Do not use them as permanent circuits. # Mechanical Safety - The practice of protecting workers from exposure to potential mechanical hazards. ## Mechanical or Machine Hazard - Refers to any dangers and risks that are caused by the moving parts of machinery or equipment. ## Machine - Refers to a tool or equipment that multiplies work. ## Basic Types of Hazardous Mechanical Motions and Actions - **Mechanical Motions:** - **Rotating Movement:** The circular movement of an object around a center of rotation. A three-dimensional object always rotates around an imaginary line called a rotation axis. - **Reciprocating Movement:** Back and forth, or up and down, motion in a straight line of a mechanism. - **Traversing Movement:** Forward straight motion of the mechanism. - **Mechanical Actions:** - **Cutting:** The separation or opening of a physical object into two or more portions, through the application of an acutely directed force. - **Punching:** The metal forming process that uses a punch press to force a tool, through the work piece, to create a hole via shearing. - **Shearing:** The process of cutting sheet metal to size out of a larger roll or flat stock. - **Bending:** Deforming metal by applying force to the subject, which causes it to bend at an angle and form the anticipated shape. ## Mechanical Hazards Occur At: 1. **Power Transmission Apparatus:** Components of the mechanical system which transmit energy to the part of the machine performing the work 2. **Point of Operation:** The area on a machine where work is actually performed upon the material that is being processed. 3. **Other Moving Parts:** All parts of the machine that move while the machine is performing its work. ## Mechanical Safety Practices - **Machine Guard** Protective devices that cover moving pieces of machinery and protect workers. - **Preventing Access:** Machine guards that prevent arms or any parts of the body from contact with the moving parts of the machine. - **Fixed Enclosing Guards:** Permanent machine guards that are attached to the machine. They do not have moving parts and cannot be moved while the machine is in use. - **Movable Guards with Interlocking Switches:** These guards ensure that hazardous machine functions are stopped and that an unexpected restart is reliably prevented. - **Two Hand Controls:** These controls protect the machine operator from physical injuries, such as being crushed or pulled into the machine, by ensuring that both hands remain outside of the hazardous area as long as there is a danger. - **Preventing Dangerous Motion:** When frequent access is required, physical guarding at the hazard is sometimes too restrictive for part loading or adjustment. - **Pullback Device:** A system of cables that are attached to the operator's hands, wrists, and/or arms. - **Restraints:** Cables or straps that are attached to the operators hands and a fixed point. - **Photo Electric Light Curtains:** These are designed to protect personnel when operating close to hazardous machinery. - **Safety Mats:** These devices are used to guard the floor area around a machine. - **Pressure Sensitive Edges:** Used to protect personnel from injury or equipment from damage. - **Emergency Stops:** A simple, highly visible button designed to shut down operations on heavy or dangerous equipment. - **Grab Wire Switches:** An emergency stop switch that is hung by a cable around a piece of machinery. - **Telescopic Trip Switches:** A type of switch with a telescopic antenna, where deflection of the antenna causes the switch to cut off the machine power. - **Protective Shields:** Provide protection against flying particles, splashing cutting oils, or coolants. - **Hand Feeding Tools:** Hand-held tools designed for placing or removing material or parts to be processed within or from the point of operation. ## Hazardous Energy Sources Found in the Work Place 1. **Electrical Energy:** Uncontrolled current and voltage that power electrical equipment. 2. **Mechanical Energy:** The sum of potential and kinetic energy. 3. **Thermal Energy:** The energy contained within a system that is responsible for its temperature. Heat is the flow of thermal energy. 4. **Potential Energy:** Energy that is stored in an object or system of objects. # Conclusion - Thank you for listening!