![ CHARACTERISTICS OF FIRE :
1) Fire can cause large losses ( human & materials)
2) Chemical reaction requires three components : Fuel , Oxygen ,
Ignition source [ Fire triangle ].
3) Ignition can be caused by convection , conduction & radiation .
4) Several type of combustion process depending on the combustion
rate.
A) Slow combustion ( no flames , very low temp )
B) Normal combustion ( controlled combustion rate )
C) Explosion ( very quickly )
D) Detonation ( very quickly & propagates very quickly ) chrome
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Fire and explosion hazards
- 1. FIRE AND EXPLOSION PREPARED BY- SANJAY KUMAR PUROHIT M.PHARM(Q.A)
- 2. INTRODUCTION FIRE: - it is the rapid oxidation of a material in the exothermic chemical process of combustion , releasing heat , light & various reaction products . - Fire prevention in the workplace starts out with knowledge of knowing different types of fires & how to control them in the case of emergency. - There are four different types of fires .each of which have different fire extinguishers to be used . Types Of Fires : 1) Class A Fires : 2) Class B fires : 3) Class C fires : 4) Class D fires : 2
- 3. 1) Class A Fire : - These are fires in ordinary combustible materials such as wood , cloth ,paper etc. Those produce glowing ember . 2 ) Class B Fire : - These are the fires of flammable petroleum , liquids , gases & greases etc.. 3
- 4. 3) Class C Fire : -These fires involved energized electrical equipment . -These fires are the one that come from equipment such as power lines & transformers . 4) Class D Fire : -These are fires in combustible metals. -In this type of fire where metal used in the workplace is unstable & catch on fire . Or the metal could be stationary & because of certain environment conditions & its chemical compound it could immediately react & combust . Ex. – aluminium , titanium ,magnesium . 4
- 5. CHARACTERISTICS OF FIRE : 1) Fire can cause large losses ( human & materials) 2) Chemical reaction requires three components : Fuel , Oxygen , Ignition source [ Fire triangle ]. 3) Ignition can be caused by convection , conduction & radiation . 4) Several type of combustion process depending on the combustion rate. A) Slow combustion ( no flames , very low temp ) B) Normal combustion ( controlled combustion rate ) C) Explosion ( very quickly ) D) Detonation ( very quickly & propagates very quickly ) chrome 5
- 6. Influencing factors 1) Flash point (Minimu m ignition temp.) 2) Auto ignition temp. 3)Concentration of gas 4) Density of gas 5) Catalysts 6) Oxidizing substances. Factors influencing fire : 6
- 7. Sources of fire hazards : 1) Hot surfaces 2) Combustible & flammable liquids 3) Heat utilization equipments ( over heating ) 4) chemical process equipments 5) Gas cylinders 6) Ovens & surfaces 7) Reactor 8) welding & cutting 9) spark from metal to metal contacts 10) carelessness 7
- 8. EXPLOSION 8 • An explosion is a rapid increase in volume & release of energy in an extreme manner , usually with generation of high temp. & the release of gases. •Supersonic explosion created by high explosives are known as Detonations & travel via supersonic shock waves. •Subsonic explosions are created by low explosives through a slow burning process known as Deflagration. •There are several types of explosion that can happen , some more common in the workplace than others . Most of which are not even possible to occur in everyday circumstances . •Difference between fire & explosion is the rate at which energy is released . In fire it is at slow rate & in explosion it is at high rate & sudden release.
- 9. 9 Types of explosion : 1) Natural explosion : - These are the explosions that occur in nature such as volcanic eruptions & explosions , during forest fires from the igniting of oils in three tops. 2) Chemical explosion : - These are the most common explosion that occur, mostly in the areas that use it during the job operation such as ammunition testing areas. - These type including explosion such as gun powder , TNT, & dynamite.
- 10. 10 3) Nuclear explosion : -This is an explosion derived from fission & fusion in a nuclear reaction , even the smallest nuclear weapon is powerful enough to destroy an entire city , making them deadly hazard. 4) Electrical explosion : -Excessive magnetic pressure within an ultra – strong electromagnet can cause a magnetic explosion . - A lightning bolt is another form of electric explosion . 5) Astronomical explosion : - It is biggest type of explosion & are also the least possible to occur in normal circumstances.
- 11. 11 6) Mechanical explosion : - These are completely physical , mechanical , occur when a tightly sealed container under pressure encounter a break , at which it release its gases or liquids rapidly causing an explosion. Astronomical explosion
- 12. 12 INDUSTRIAL PROCESSES & HAZARD POTENTIAL Hazard : it is situation possesses a level of threat life , health , property or environment . Industrial hazard : it may be defined as any condition produced by industries that may cause injury or death to personnel or loss of product or property . Safety : it defined in simple terms means freedom from occurrence of risk or injury or loss. Industrial safety : it refers to the protection of workers from the danger of industrial accidents . Types of hazards : 1) Mechanical hazard : 2) Electrical hazard: 3) Thermal hazard: 4) Process hazard :
- 13. 13 Mechanical hazard : -It is any hazard involving a machine or process . -Motor vehicle , aircrafts & air bags , pose mechanical hazard . Compressed gases or liquids can be considered a mechanical hazard. Source of mechanical hazard : - it occurs when machine is a malfunctioning . - machines may run either manually or automatically . -A few machines are cutting , shearing , crushing & breaking . -Large number of equipments -Crowded workplace conditions . -Failure of SOP -Dangerous parts -Improper maintenance of equipments . -Electrical or power supply. Factors responsible for mechanical hazards are : a) Physical factors : physical capabilities of worker may not meet the job requirements. b) physiological factors : The various physiological factors that affect the mechanical hazards are age , sex, time & experiences .
- 14. 14 Prevention of mechanical hazards : -Requirements for safeguards - safeguard must meet these requirements : 1) Prevent contact : - It prevent hands , arms or any part of worker’s body from making Contact with dangerous moving parts . 2) Secure : - Workers should not be able to easily remove with the safeguards. Guards & safety device made up of durable material that will withstand the conditions of normal use. 3)Protect from falling objects : - The safeguard must ensure that no objects can fall into the moving objects . A small tool which dropped in a cylinder machine could easily become a projectile that could strike & injure someone. 4) Create no new hazards : - The edges of guards must be rolled or rounded in such way that eliminates sharp edges & prevent unwanted injuries.
- 15. 15 5 ) Create no interferences : -Proper safeguarding can enhances efficiency , since worker will not afraid of injuries then. -6) Allow safe lubrication : -If possible , one should able to lubricate the machine without removing the safeguards. Locating oil reservoirs outside of the guard, with a line leading to the lubrication point. - it will reduce the need of operator or maintenance worker to enter the hazardous area.
- 16. 16 Electrical hazards : -It is a dangerous conditions where a worker could make electrical contact with energized equipment or a conductor , & from which the person sustain an injury from shock . -These is a potential for the worker to receive a arc flush burn, thermal burn, or blast injury. Improper use & maintenance of apparatus Improper use of electrical outlets Overloaded circuit Improper joint of two wires Worker touch the phase having wet cloth & high humidity . Worker touches another person receiving shock. Worker receives shock from electrical components not grounded properly . Worker touches two wires at different voltages at same time.
- 17. 17 Prevention of electrical hazard : A) ELECTRICAL SAFETY POLICY : - Power equipment should be plugged into wall receptacles with power switches in the off positions. - Electrical equipment should be unplugged by grasping the plug & pulling. Never pull or jerk the cord to unplug the equipment. - Cracked , exposed wiring on equipment cords must be corrected . - Temporary or permanent storage of material must nor allowed within the 3 feet of electrical equipment . - Any electrical equipment causing shocks or which has high leakage potential must be tagged with DANGER – DO NOT USE label or equipment.
- 18. 18 B . Responsibilities of individual employee : 1)Training & education : - Employees should be trained in electrical safety work practices & equipment operation . 2)Hazardous conditioning reporting : - Employees should always report unsafe equipment conditions or procedure . 3)Work practices : - Employees always follows safe work practices , procedures & policy. 4)Housekeeping : - Good housekeeping requires all employees to observes activities that could cause electrical shock hazards . Ex . Electrical equipment that is not properly grounded in the areas that have water on the floor can create shock hazards . - cleaning tools & electrical equipment with solvents can create health & physical safety problems .
- 19. Fire (Thermal) Hazards Fire is an exothermic chemical reaction between oxygen and fuel. Combustion Slow combustion eg: cotton waste burning Rapid combustion eg: petroleum product Spontaneous combustion eg: paint, scrap The effect of fire on people take the form of skin burns Fire can take several different forms including jet fires pool fires and boiling liquid expanding vapour explosion. 19
- 20. Sources of fire hazards :- 1) Hot surfaces 2) Combustible & flammable liquids 3) Heat utilization equipments ( over heating ) 4) chemical process equipments 5) Gas cylinders 6) Ovens & surfaces 7) Reactor 8) welding & cutting 9) spark from metal to metal contacts 10) carelessness 20
- 21. Steps to be taken Don't panic Raise the alarm Evacuate the premises Turn off the gas supply Attack the fire with extinguisher vacate the place In case of fire safe methods to be followed Stair cases only to be used for evacuation Exit doors should be closed after getting out Go down the stair case to the ground Walk do not run 21
- 23. 4. Process hazards:- Process hazard due to dust, sticky material, and previous contamination of other products. Sources of dust hazards:- grinding or milling of drugs,excipients. during weighing dusts may flot on air. during powder mixing dusts may be generated. during coating operation dust are generated. during capsule filling and tablet punching dusts may be generated. 23
- 24. Prevention of dust hazards:- 2. Filtration 24 1.Inerital separation 3.Electrostatic separator
- 25. Types of extinguisher:- Water based Dry powder based ( ABC extinguisher) Foam based Wet chemicals and water additive based Carbon dioxide based 25
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- 27. The hazard management process: i. Identification of the hazards. ii. Determination whether the hazard can be eliminated or isolated. iii. Assessing the remaining hazard to determine whether they are principle hazard or significant hazard. iv. Developing and introducing principal hazard management plans for principal hazards. v. Developing and introducing principal control plan for all principal control mechanisms. vi. For remaining hazard where they can not be eliminated or isolated , conducting a risk assessment to minimize the likelihood of the hazard vii. Participation of workers in the identification , assessment and control hazard 27
- 28. • Procedure:- 1. Identification of hazard This is a fundamental step in hazard management. Some ways of identifying the hazard: Workplace inspection Incident reporting Consultation with employees Feedback from employs 28
- 29. 2. Risk assessment After identification of hazard need to assess the risk created by each hazard will cause, injury , illness or disease. 3. Hazard control It is not enough to just find and rate the hazard’s. After find the hazard is important to eliminate or control the hazard before the injury or illness of people due to hazard 4. Evaluate , monitor and review It is important to know if your risk assessment was complete and accurate , it is also essential to be sure that changes in the workplace have not introduced new hazards. 29
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- 31. EXPLOSION An explosion is a rapid increase in volume and release of energy in an extreme manner, usually with the generation of high temperatures and the release of gases. There are three fundamental types Mechanical Nuclear Chemical. A mechanical explosive is one that depends on a physical reaction. such as overloading a container with compressed air. 31
- 32. A nuclear explosive is one in which a sustained nuclear reaction can be made to take place with almost instant rapidity, releasing large amounts of energy. Chemical explosives are of two types: (1) Detonating, or high, explosives and (2) Deflagrating, or low, explosives. Detonating explosives, such as TNT and dynamite, are characterized by extremely rapid decomposition and development of high pressure, whereas deflagrating explosives, such as black and smokeless powders, involve merely fast burning and produce relatively low pressures. Under certain conditions, such as the use of large quantities and a high degree of confinement, some normally deflagrating explosives can be caused to detonate. 32
- 33. For example, at high temperatures (> 2000 °C) a mixture of nitrogen and oxygen can be made to react rapidly and yield the gaseous product nitric oxide; yet the mixture is not an explosive since it does not evolve heat, but rather absorbs heat. N₂ +0,2 NO-43,200 calories (or 180 kJ) per mole of N 33
- 34. MECHANICAL EXPLOSION A physical process, as opposed to chemical or nuclear, e.g.. the bursting of a sealed or partially sealed container under internal I pressure is often referred to as a mechanical explosion. Examples include an overheated boiler or a simple tin can of beans tossed into a fire A mechanical explosion may be illustrated by the gradual buildup of pressure in a steam boiler or pressure cooker. As heat is applied to the water inside the boiler, steam is generated. If the boiler is not equipped with some type of safety valve, the mounting pressure will eventually reach a point at which it will overcome the structural or material resistance of its container and an explosion will occur. Such a mechanical explosion will be accompanied by high temperatures. a rapid escape of gases or steam and a loud noise. 34
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- 36. CHEMICAL EXPLOSION A chemical explosive is a compound or mixture which, upon the application of heat or shock, decomposes or rearranges with extreme rapidity, yielding much gas and heat.For a chemical to be an explosive, it must exhibit all of the following: Rapid expansion (i.e., rapid production of gases or rapid heating of surroundings) Evolution of heat Rapidity of reaction Initiation of reaction 36
- 37. There are many chemical reactions that will release energy. These are known as exothermic reactions. If the reaction proceeds slowly, the released energy will be dissipated and there will be few noticeable effects other than an increase in temperature. On the other hand, if the reaction proceeds very rapidly, then the energy will not be dissipated. Thus, a great quantity of energy can be deposited into a relatively small volume, then manifest itself by a rapid expansion of hot gases, which in turn can create a shock wave or propel fragments outwards at high speed. Chemical explosions may be distinguished from other exothermic reactions by the extreme rapidity of their reactions. In addition to the violent release of energy, chemical explosions must provide a means to transfer the energy into mechanical work. This is accomplished by expanding product gases from the reaction. If no gases are produced, then the energy will remain in the products as heat. 37
- 38. MULTIPHASE REACTIONS A multiphase reaction refers to reactions involving components in different phases, and is a combination of simultaneous phase change and conversion of some materials into others. Multiphase reaction and reactor are in chemical allied industry have great economic and ecological importance. 38
- 39. Classification based on number of phases: • Gas-solid catalytic • Gas-solid non catalytic • Gas-liquid solid catalytic • Gas-liquid solid reaction • Liquid-liquid • Gas-liquid-liquid-solids 39
- 42. Conti.. Multiphase reactions are very common in the pharmaceutical industry and include. e.g., hydrogenations, oxidations, halogenations and phase-transfer catalysis reactions. They involve combination of two or more immiscible phases (e.g., liquid. liquid, solid-liquid or gas-liquid reactions). 42
- 43. Conti.. When mass transfer from one phase to the other is the rate-determining step, it crucial to maximize the interfacial area. In batch, the interfacial area is low and poorly defines, thus, leading to prolonged reaction times. Due to the small characteristic dimensions of micro reactors, large and well defined interfacial areas are observed, typically orders of magnitudes higher than in traditional batch environments. These large interfacial areas lead to efficient mass transfer between the two phases. 43
- 44. Strategies of selection of multiphase reaction: 44
- 45. Conti.. Continuous flow (micro) reactor technology therefore offers the unique possibility to perform multiphase reactions, in particular gas-liquid chemistry, with unparalleled efficiency and process safety. Gases can be dosed into the flow system with precise stochiometry using mass flow controllers and intense mixing of the gaseous and liquid phase can be achieved. Furthermore, high pressure operation increases the concentration of the gas in the liquid phase. Combustion and explosion hazard are reduced in channels of small diameter and, consequently, reactions can be performed under unusually harsh process conditions in a safe and controllable manner 45
- 46. TRANSPORT EFFECTS Dangerous goods can be transported without causing unnecessary properly and with care hazards if inhaled. 1 WHAT ARE DANGEROUS GOODS? Dangerous goods can be explosive, flammable, toxic, radioactive, corrosive or harmful in some other way to humans, animals, or the environment. 50% of transported goods are dangerous. 46
- 47. Conti.. United Nations statistics show that half of all goods transported belong to the category of dangerous goods. Petroleum products transported by tankers form a large proportion of all transported goods, but road and railway transport is also significant. For example, 85% of chlorine, which is one of the very dangerous chemicals, is transported by rail. Large amounts of other highly dangerous goods, such as hydrochloric acid, sulphuric acid, sulphuric dioxide, nitric acid, phenol and methanol are transported regularly. Major accidents caused extensive damage but that is not all. 47
- 48. Conti.. We forget easily that small amounts of oil, gasoline, battery acids and refrigerator fluids are released to environment daily. Even small but frequent wastes from ships. households, cars or agriculture increase the load to the environment. 48
- 49. For example: one litre of oil can, under unfavourable circumstances, spoil 100000 litres of drinking water. A spill of hydraulic fluid from a truck can lead to environmental damages. 49
- 50. 2 DANGEROUS SITUATIONS • There is always a risk of spillage during the transport of hazardous goods. When incompatible substances mix with each other there is a possibility of chemical reaction. which can produce enough heat to cause fire or explosion and can release dangerous gases. 50
- 51. Conti.. For example, toxic nitrous oxides are formed when ammonium nitrate (in fertilizers) decomposes in a fire. Another example is the toxic gases which fume off when a spillage of concentrated sulphuric acid is absorbed in sawdust. • Special conditions can increase the risks A chemical substance or preparation may be hazardous in itself when it comes into contact with other chemicals including air, water or humidity. For example, when calcium carbide (used in the production of acetylene and pyrotechnics) comes to contact with water, it releases the extremely flammable gas acetylene (used in welding flame) and creates an explosion hazard. 51
- 52. VEHICLE REQUIREMENTS Transport by road may take place as bulk materials, or in containers and tanks. The detailed technical requirements for different transport methods are usually given in national regulations. 52
- 53. • Declaration that the packing and labelling is properly done. • Transport emergency card (instructions in writing in case of accident or emergency that may occur during transport) • Certificate of approval given by technical inspection for the tank and vehicle. • Labels and placards for the vehicle. • Driver's training certificate The transporter should check that the following documents are attached Transport document (letter of consignment) 53
- 54. Global rates Global chemical industry generate more then 2 trillion USD gross income They are larger contributor to GDP Distribution 54
- 55. Accident Statistics Fire and explosion contribute substantially to the risk associated with chemical plant. 55
- 56. PREVENTIVE AND PROTECTIVE MANAGEMENT FROM FIRES AND EXPLOSION
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- 58. Electricity passivation: • Passivation includes the creation of an outer layer of guard/ shield material that is applied as a micro-coating in semi-conductor devices of metallization films to reduce the environmental effects. • Passivation layers can be both organic and inorganic in nature, among organic passivation layers, PI materials have been widely used in electronic devices due to their goo high temperature resistance, excellent mechanical and electrical properties, and high chemical stability. 58
- 59. Ventilation The purpose of ventilation is to dilute the explosive vapours with air to prevent explosion and to confine the hazardous flammable mixtures. Always provide adequate ventilation to reduce the potential for ignition of flammable vapours. Open Air Plants: Average wind velocities are high enough to safely dilute volatile chemical leaks which may exist within a plant. Plant Inside Buildings 59
- 60. Types of ventilation: a. Local exhaust ventilation: Local exhaust ventilation systems remove the contaminant before it spreads through the workplace. They are most useful for controlling toxic materials when their airborne concentrations could exceed legislated standards. b. Dilution/general ventilation General (dilution) ventilation systems supply clean air that mixes with the air in the workplace, diluting the concentrations of the contaminant. It is not suitable to control exposure to toxic substances because these systems actually spread the contaminant throughout the workplace before exhausting it 60
- 61. Sprinkler system: The system consists of an array of sprinkler heads connected to a water supply. The heads are mounted in a high location (usually near ceilings) and disperse a fine spray of water over an area when activated. The control point is connected to an array of heat/or smoke detectors that start the sprinklers when an abnormal condition is detected. It a fire is detected, the entire sprinkler array within an area is activated, possible in area not areas not even affected by the fire. 61
- 62. Proofing All electrical devices are inherent ignition sources. Most safety practices for electrical installations are based on the National Electric Code (NEC). Process areas are divided into two major types of environments/area Explosion Proof (XP) Flammable materials (particularly vapours) might be present at certain times Non- Explosion Proof abnormal conditions.(non-XP: Flammable materials are not present even under 62
- 63. Relief Valves A relief valve or pressure relief valve (PRV) is a type of safety valve, used to control or limit the pressure in a system; pressure might otherwise build up and create a process upset, instrument or equipment failure, or fire. Process plant can be subjected to excessive overpressure or under pressure due to External fire Process abnormality or mal-operation Equipment or service/utility failure Changes in ambient conditions Excess chemical reaction 63
- 64. Causes of safety relieve valve overpressure are: Blocked discharge Exposure to external fire, often referred to as "Fire Case’’ Thermal expansion Chemical reaction Heat exchanger tube rupture Uses of relief valves: The primary function of safety relief valves is the protection of life, property and environment. A safety relied valve is a device designed to protect a pressurised vessel or system against over-pressure should all other safety system fails. 64
- 65. Flare: A flare, also sometimes called a fuse, is a type of pyrotechnic that produces a bright light or intense heat without an explosion. Flare is used for distress signalling, illumination, or defensive countermeasures in civilian and military applications. Flares may be ground pyrotechnics, projectile pyrotechnics, or parachute-suspended to provide maximum illumination time over a large area. A gas flare, alternatively, known as a "llare stack", is a gas combustion device used in industrial plants such as petroleum refineries, chemical plants and natural gas processing plants. They are also common at oil or gas extraction sites having oil wells, gas wells, offshore oil and gas rigs and landfills. 65
- 66. Gas flares burn up the flammable gases released by pressure relief valves when flammable gases are emitted by different types of plant equipment. This prevents these excess gases, which may be harmful, from leaking into the area immediately surrounding the equipment. Flaring most often occurs during start- up and shut down, when large amounts of excess gas are built up. 66
- 67. Scrubbers: Scrubbers are air pollution control devices that use liquid to remove particulate matter or gases from an industrial exhaust or flue has stream. This atomized liquid (typically water) entrains particles and pollutant gases in order to effectively be them out of the gas flow. They are also capable of handling explosive and flammable gases safely. However, scrubbers suffer from high levels of corrosion and produce slurry waste streams which are less convenient for recycling and disposal. 67
- 68. The major types of industrial scrubbers are a. Wet scrubbers: One of the most basic of the various industrial scrubbers is the wet industrial scrubber. In its most basic form, water is encapsulated in a metal or composite container. Contaminated gas is passed through the water, and the water absorbs the contaminants. Other liquids can be used to effectively remove varied contaminates. These liquids differ in the chemical composition and the overall charge b. Dry scrubbers: A dry industrial scrubber is composed of a reaction centre where the sorbent or dry reaction material that absorbs contaminants is mixed with the polluted gas. Also within the system is material component that aids in the removal of the reaction product, which is the dry sorbent bound to the pollutant. Dry scrubbers are used primarily to remove acids found within gasses. 68
- 69. C Electrostatic precipitators: Electrostatic precipitators function uniquely from the different types of industrial scrubbers by using charged to remove dust and other contaminants from a gas. It is important to match the polarity and type of charge to bind to and remove the pollutants from the gas. An example of the design of an electrostatic precipitator is a plate precipitator. The plate is a sheet of metal that is charged with a specific type of charge. These plated are designed to run parallel with the piping so that the gas will pass through by the plate and the plated will remove the dust or contaminate. 69
- 70. Thankyou 70