Lecture 4 Industrial Hazards Engineering.pptx

Industrial Hazards

1. (MS-101) HEALTH, SAFETY AND ENVIRONMENT Lecture 4 – Industrial Hazards ( Health, Safety and Environment ) Department of Energy Engineering 1

2. Department of Energy Engineering CONTENTS Industrial Hazards Fires Explosions 2

3. Department of Energy Engineering INDUSTRIAL HAZARDS Hazard means danger, risk; Hazardous means dangerous, risky. Hazard is a condition with the potential of causing harm or damage to resources of any kind: man, property, air, water, land, flora and/or fauna. Natural products are not hazardous under a given set of conditions but when any material is synthesized to produce a chemical substance having any one of these properties: Flammable, explosive, corrosive, toxic, or if it readily decomposes to oxygen at elevated temperature; it is considered as hazardous. 3

4. Department of Energy Engineering INDUSTRIAL HAZARDS Some specific examples of hazardous materials include: Chlorine is toxic when inhaled Sulfuric acid is extremely corrosive to (eating into or gradually wearing away) skin Ethylene is flammable Steam confined in a drum at 600 psig contains a significant amount of potential energy Acrylic (synthetic) acid can polymerize (process of joining two or more like molecules), releasing large amount of heat. These hazards cannot be changed and they are the basic properties of the materials and the conditions of usage. The inherently safe approach is to reduce the hazard by reducing the quantity of the hazardous material or energy, or by completely eliminating the hazardous agent. 4

5. Department of Energy Engineering INDUSTRIAL HAZARDS A hazard in the process industry is the escape of process material, which may be inherently dangerous (toxic or flammable) and/or present a high pressure and high or low temperature. Large and sudden escape may cause explosion, toxic clouds and pollution whose effects extend beyond the premises of a factory or an industrial establishment. Examples: In 1984 the explosion of liquefied petroleum gas in Mexico City causing 650 Deaths. The release of toxic methyl isocyanate gas in Bhopal, India causing 2000 deaths and 200,000 injuries. Methane – coal dust explosions in many underground coalmines all over world . 5

6. Department of Energy Engineering INDUSTRIAL HAZARDS Hazards differ from industry to industry and even from process to process within the same industry. Their magnitude depends mainly on the materials involved, their quantity and their quality. List of hazards Acute toxicity Chronic toxicity Flammability Reactivity Instability Extreme conditions (temperature or pressure) 6

7. Department of Energy Engineering INDUSTRIAL HAZARDS List of hazards Environmental hazards including Air pollution Water pollution Ground water contamination Waste disposal Disaster Disaster: This means a major accident or natural event or natural calamity involving loss of lives (human and other creatures), property and resources. It could be a natural or manmade disaster. The definition differs from country to country . 7

8. Department of Energy Engineering INDUSTRIAL HAZARDS Health risk A hazard ultimately causes risks to health as shown in Figure. 8

9. Department of Energy Engineering FIRES Fire or Combustion is a chemical reaction in which a substance combines with an oxidant and releases energy. Part of the energy released is used to sustain the reaction. The Fire Triangle concept as shown in Figure 6.1, is used to understand the mechanism of fires. The Fire Triangle Concept All materials (solid, liquid or gas), which will burn are known as combustibles. 9

10. Department of Energy Engineering FIRES The Fire Triangle Concept There must be a thorough balance amongst three elements: fuels, oxidizer and ignition source, like the three sides of a triangle, for a fire or explosion to onset (Figure 6.1), while the absence or withdrawal of any of them would not allow the fire or explosion to set or continue. FUELS: Almost all organic chemicals and mixtures in the solid, liquid or gaseous state are flammable, and as such they are potential fuels. Solids: Wood, cotton fabrics, papers, coal, fibers. Liquids: Oil, fats, petrol, gasoline, acetone, ether, pentane. Gases: LPG, acetylene, propane, carbon monoxide, hydrogen. 10

11. Department of Energy Engineering FIRES The Fire Triangle Concept OXIDISER: Oxidant can be solid, liquid or gaseous. Gases: air, which contains 21% oxygen (Oxygen-rich atmosphere). Other examples include Chlorine, Nitrogen chlorine trifluoride, Nitrogen oxides. Liquids: hydrogen peroxide, nitric acid, perchloric acid, chromic acid. Solids: metal peroxides, ammonium nitrate, permanganates. AN IGNITION SOURCE: Spark, flame, jolt, friction, shock, incandescent sparks, or heat from a light bulb. Electrical discharge from making or breaking of an electric circuit or from static electricity also constitutes a possible means of ignition. In addition, an open fire, hot surface, non-intrinsically safe electrical equipment, mechanically-generated sparks, static electricity and smoking materials could be added to this list. 11

12. Department of Energy Engineering FIRES Ignition sources of major fires Table describes major ignition sources for fires based on experience gained in this aspect. 12

13. Department of Energy Engineering FIRES Ignition sources of major fires 13

14. Department of Energy Engineering FIRES Classification of fires Table describes different classes of fires and type of extinguishers to deal them. 14

15. Department of Energy Engineering FIRES Fire protection Adhering to the guidelines given below could minimize the incidence of fire. Fire detection and protection equipment should be provided in accordance with laid out norms and prevalent regulations. Fire-blankets should be made available in kitchens. Such fire-blankets should be manufactured from woven glass fiber, or equivalent. A facility for general audible alarm should be provided in all areas of risk. Plans and procedures should be put in place for Fire prevention Building evacuation and muster points Fire fighting Maintenance (including periodic testing) of fire protection equipment. All fire escape routes and exit doors, alarm points and fire fighting equipment should be kept clear of obstructions at all times. 15

16. Department of Energy Engineering FIRES Fire protection Fire wardens (officials) should be appointed for all accommodation and office buildings, in sufficient numbers such that in the event of a fire, control and safe evacuation of personnel to allocated muster points could be efficiently accomplished. All personnel should be familiar with the fire emergency procedures, alarms and equipment available, personal responsibilities and evacuation procedures in the event of a fire alarm. Regular fire drills should be performed to ensure this. All flammable liquids, such as photocopier toners, cleaning solvents and draughtsman's sprays, should be stored away from sources of heat and ignition or naked flame, in metal cabinets. Only quantities in direct use should be brought into the workplace. Empty containers and aerosols, which have contained flammable liquids, should be disposed of forthwith in a secure lidded refuse container and in accordance with the laid out procedures and prevalent regulations. 16

17. Department of Energy Engineering FIRES Fire protection Fire wardens (officials) should be appointed for all accommodation and office buildings, in sufficient numbers such that in the event of a fire, control and safe evacuation of personnel to allocated muster points could be efficiently accomplished. All personnel should be familiar with the fire emergency procedures, alarms and equipment available, personal responsibilities and evacuation procedures in the event of a fire alarm. Regular fire drills should be performed to ensure this. All flammable liquids, such as photocopier toners, cleaning solvents and draughtsman's sprays, should be stored away from sources of heat and ignition or naked flame, in metal cabinets. Only quantities in direct use should be brought into the workplace. Empty containers and aerosols, which have contained flammable liquids, should be disposed of forthwith in a secure lidded refuse container and in accordance with the laid out procedures and prevalent regulations. 17

18. Department of Energy Engineering FIRES Fire protection No Smoking’ signs should be strictly obeyed. Where smoking is permitted, cigarette butts and spent matches should be disposed of in specifically designated ashtrays or sand containers. Appliances such as electric heating rings should not be permitted in normal office space, but should be confined to designated cooking areas. However, domestic electric kettles and coffee percolators may be placed in the general office space provided they are positioned securely, and are supplied directly with a power point. They should not be powered via an extension cord. On-line gas bottles for use in kitchens or laboratories should be located outside. If the bottles are placed closer than 5 m from combustible materials, a block-work separation wall should be constructed. Any enclosure for the gas bottle(s) should be freely ventilated. Storage cupboards for stationery and other flammable materials should be metallic and, when not in a dedicated storage room, fitted with doors. 18

19. Department of Energy Engineering FIRES Fire and emergency In the event of a large uncontrollable fire: Close or stop the source of fire, if you can. Sound the alarm by breaking the glass. Telephone emergency number (1234–**As applicable to the place where fire occurred.) Leave the building using nearest exit. Go to nearest Assembly Point. If you hear a FIRE ALARM: Leave the building using nearest exit. Do not run. Do not stop to collect personal belongings. Do not re-enter the area before fire brigade permits. 19

20. Department of Energy Engineering FIRES Fire and emergency . If the FIRE is SMALL: Use a Fire Extinguisher to extinguish it. Don’t operate Fire Alarm or Fire Bell. The following is the procedure for using a Fire Extinguisher. It is denoted by: ‘ PASS ’ that signifies: Pull the pin Aim the extinguisher at the base of the flames Squeeze the trigger, holding the extinguisher upright Sweep the extinguisher from side to side, covering the area with the extinguishing agent. 20

21. Department of Energy Engineering EXPLOSIONS It is a phenomenon in which there is a sudden widespread expansion/increase of gases in rapidly moving pressure or shock wave. The expansion could be mechanical, or it could be result of a rapid chemical reaction. It is a noisy outburst. The damage is caused by the pressure or shock wave. The basic difference between fires and explosions is the rate of release of energy. It is faster in the case of explosions compared with fires. Fires can result from explosions, and vice versa is also true. Figure 6.4 classifies explosions, which could be due to various reasons. 21

22. Department of Energy Engineering EXPLOSIONS It. 22

23. Thank You Department of Energy Engineering 23