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Continue Continue Exit Filter FINISH finish Definition definition Glossary Terms Menu Please rotate your device NEXT next Notes Notes Bio More info Captions pause play Send an email PREV previous Question List replay Additional Resources resources Restart Resume Search... search Search in: Search Results Back to top Slide Text SUBMIT ALL submit all SUBMIT submit volume a guide of symbols used in this course key terms learner activity questions additional resources element 4 fire and explosion protection this element looks at fire and explosion hazards and how the effects can be minimised. it will also explore dust explosions and how to prevent them and will then look at reasons for developing an emergency plan. 4.1 explain fire and explosion hazards relating to process industries. 4.2 outline appropriate control measures to minimise the effects of fire and explosion in the process industries. 4.3 outline how dusts have the potential to explode and commonly used control measures adopted to prevent and minimise explosion. 4.4 outline the purpose and features of an emergency plan and the requirements for the implementation. learning outcomes element 4: fire and explosion protection 4.1 fire hazards. 4.2 fire and explosion control. 4.3 dust explosions. 4.4 emergency preparedness. activity what heat sources and fuels do you have in your organisations? learner activity think about this and complete the activity on the next slide before progressing. correct match these items to the common heat sources and common. close close close close close close fuels heat source smoking naked flames (e.g. use of welding), hot surfaces (process equipment, etc.) electrical discharge, sparking, lightning petrol oil plastics incorrect that is incorrect. please try again. try again try again try again try again try again try again incorrect you did not select the correct response. see answer see answer see answer see answer see answer see answer incorrect correct that's right! you selected the correct response. continue continue continue continue continue continue correct match these items to the common heat sources and common. fuels heat source smoking naked flames (e.g. use of welding), hot surfaces (process equipment, etc.) electrical discharge, sparking, lightning petrol oil plastics submit submit submit submit submit submit the fire triangle a fire needs three elements - heat, oxygen and fuel. without heat, oxygen and fuel a fire will not start or spread. a key strategy to prevent fire is to remove one or more of heat, oxygen or fuel. the risk assessment should include detail on all three elements to minimise the risk of a fire starting/ spreading. modes of heat transfer convection hot fluids rise and cold fluids sink, and as this happens, heat is spread upwards from the seat of the fire radiation transfer of radiant energy from hot objects conduction transfer through solid materials typical ignition sources in the process industry many examples including: smoking; sparks; naked flames, eg as oxy-acetylene welding; processes involving electrical discharges, eg arc welding; hot surfaces; mechanical friction; lightning. flammable/explosive ranges describe using the diagram: lower flammable limit - below which the fuel/air mixture is too lean to ignite upper flammable limit – above which the fuel/air mixture is too rich to ignite flammable range – in between! video watch this acetylene van explosion research video. acetylene van explosion research case study key messages acetylene should only be carried in open vehicles where reasonably practicable ventilation in the form of roof and side vents reduce the risks arising from leaking acetylene industry standard precautions relating to the care and use of acetylene reduce the likelihood of any leaks learn more about acetylene research. jet fires mechanism continuous, directed, spray of fuel ignited immediately. gas, liquid or vapour. consequences ‘blowtorch’ jet of flame. radiated heat. can explode. pool fires mechanism spillage of liquid fuel. can be on water. vapour ignites above pool. consequences may flow if not contained. unburnt fuel my form a vapour cloud which can explode. typical mechanism external jet fire attack - tank walls heat up. liquid boils - prv operates. vessel weakens - crack develops. catastrophic vessel rupture. rapid depressurisation of superheated contents - cloud of fine droplets formed. consequences missiles, fireball, secondary explosion. boiling liquid expanding vapour cloud explosion (bleve) boiling liquid expanding vapour cloud explosion (bleve) in the process industry, bleves are most commonly associated with flammable liquids – but bleves can also occur with non-flammable liquids. simplified sequence (there are some variations to this depending on liquid fill level, temperature, pressure relief valve (prv) etc): direct flame external heating of tank (e.g. an existing jet fire attacking the tank) the tank walls heat up – the walls above the liquid level heat up first (the parts in direct contact with the liquid inside heat up more slowly than the parts in contact with the vapour – due to the cooling effect of the liquid) the liquid starts to boil inside (as the temperature continues to rise) boiling liquid expanding vapour cloud explosion (bleve) pressure rises and the pressure relief valve (prv) operates to halt the pressure rise (allowing escape of some vapour) continuing temperature rise of the vessel walls (the ones in contact with the vapour) causes vessel weakening crack begins to appear in the vessel wall crack suddenly gets much bigger – total loss of containment (catastrophic failure which has sometimes been described as ‘unzipping of the vessel’) rapid depressurisation (sudden release of pressure from loss of containment) causes the superheated boiling contents to suddenly form a rapidly expanding cloud of fine droplets fireball develops (ignited by the existing fire) video watch this video of bleve. confined vapour cloud explosion(cvce) mechanism flammable vapour builds up within building, vessel, etc. ignition occurs. consequences shockwave. overpressure. heat. missiles. mechanism flammable vapour. ignited before it disperses. consequences shock waves. overpressure. heat. unconfined vapour cloud explosion(uvce) when the vapour cloud forms in an unconfined space, generally outdoors, the formation and spread of the cloud depends on atmospheric conditions, such as wind speed. such clouds may form from large loss of contents of a vessel, storage tank or pipeline. if the cloud comes into contact with a source of ignition, it may flash (ignite) or even explode. unconfined vapour cloud explosion(uvce) the loss of containment at buncefield is an example of such an explosion. thermal radiation (heat) and shock waves will be released, which can be massively destructive. this may also produce a large overpressure causing damage to the surroundings and releasing missiles as with a cvce. once the cloud has dispersed and is diluted below the lel(lower exposure limit), then there is no longer a risk of ignition. unconfined vapour cloud explosion(uvce) the loss of containment at buncefield is an example of such an explosion. thermal radiation (heat) and shock waves will be released, which can be massively destructive. this may also produce a large overpressure causing damage to the surroundings and releasing missiles as with a cvce. once the cloud has dispersed and is diluted below the lel(lower exposure limit), then there is no longer a risk of ignition. unconfined vapour cloud explosion(uvce) 4.1 fire hazards. 4.2 fire and explosion control. 4.3 dust explosions. 4.4 emergency preparedness. element 4: fire and explosion protection leak detectors operation (for gas/vapour leaks) chemical sensor with alarm. initiate investigation or shut-down. manual or automatic. spot and line detectors spot detectors: localised detectors installed at a specific point. only isolated areas may be covered. line detectors: a long cable is installed which can detect heat along its length. larger area can be covered. smoke detectors operation: smoke enters chamber. light or radiation beam disrupted. alarm sounds. flame detectors operation: flickering or radiation emitted by fire. detected by sensor: visible, uv or ir detectors. alarm sounds. active and passive systems active fire protection: “equipment, systems and methods, which, following initiation, may be used to control, mitigate and extinguish fires.” passive fire protection: “coating or cladding arrangement..., which, in the event of fire, will provide thermal protection to restrict the rate at which heat is transmitted to the object or area being protected”. bs en iso 13702:1999 passive fire protection preformed boards, cladding, wall linings, etc. fire resistant materials bound into cement, etc. prefabricated walls, partitions, fire doors: structures made in a factory to be assembled on site. spray coatings: intumescent coatings sprayed onto structural steelwork, etc. seals and sealants: intumescent seals prevent the spread of smoke and fire. active fire protection sprinklers water or foam. heat triggers release. cools or smothers fire. gas extinguishing inert gas. smothers fire. need regular testing and maintenance. can be manual or automatic. hazardous area classification and zoning flammable vapours zone 0 – present continuously. zone 1 – present occasionally in normal operations. zone 2 – present for short durations and not in normal operations. flammable dusts zone 20 – present continuously. zone 21 – present occasionally in normal operations. zone 22 – present for short durations and not in normal operations. zoning example equipment for use in flammable atmospheres electrical and mechanical atex approved. electrical equipment categories category 1 used in all zones. category 2 used in zone 1/21 and zone 2/22. category 3 used in zone 2/22 only. explosion protection systems atmosphere control pressure relief / explosion venting automatic explosion suppression systems automatic isolation flame arrestors - active and passive isolation explosion protection systems atmosphere control maintaining an atmosphere not in flammable range. pressure relief and explosion venting designing ‘weak point’ in system. automatic suppression detects pressure rise and injects inert media. explosion protection systems automatic isolation detects pressure rise. cuts off supply. flame arrestors fine mesh. cools a flame as it passes through. activity review the piper alpha accident, are the automatic isolation in place? learner activity think about this and complete the activity on the next slide before progressing. complete close close close close close close click the icon below to download your reflection as a document file and save this for your own records. download download download download download download sample answer continue >>> continue >>> continue >>> continue >>> continue >>> continue >>> here, when a fire is detected, the system automatically cuts off the flammable liquid, feeding the area in order to prevent development of the fire. at piper alpha, there was no such process in operation and, as a result, the fuel continued to be pumped to the rig, exacerbating the incident and increasing the scale of the disaster; review the piper alpha accident, are the automatic isolation in place? type your text here… continue >>> continue >>> continue >>> continue >>> continue >>> continue >>> explosion protection systems automatic isolation review the piper alpha accident, are the automatic isolation in place? suggested answer - here, when a fire is detected, the system automatically cuts off the flammable liquid, feeding the area in order to prevent development of the fire. at piper alpha, there was no such process in operation and, as a result, the fuel continued to be pumped to the rig, exacerbating the incident and increasing the scale of the disaster; chemical, foam and inert gas systems chemical systems, eg dry powder inert powder smothers fire. effective on jet and running pool fires. can reignite. messy/causes damage. foam water based foam smothers fire. good for pool fires, not on jet fires. can reignite if foam layer is broken. inert gas removes oxygen and smothers. an asphyxiant so needs stringent controls. chemical, foam and inert gas systems fire protection for tank farms water monitors high volume water cannon. fixed or portable. sprinklers water or foam. deluge systems high volume sprinklers. cool and shield vessels. mitigation of lightning strikes lightning rod attached to highest point. connected to earth rod by cables. directs the electrical discharge to earth. 4.1 fire hazards. 4.2 fire and explosion control. 4.3 dust explosions. 4.4 emergency preparedness. element 4: fire and explosion protection why dust explosions occur the dust pentagon conditions needed: oxygen ignition source e.g. spark of sufficient energy fuel (combustible dust – but humidity affects this too) confinement within hopper, silo, room etc. dispersion of the dust (sufficiently fine (particle size) to form a cloud in the right concentration range in air) primary and secondary explosions primary explosion initial explosion within the process. may disturb lying dust in the room. secondary explosion often much larger. involves dust stirred up by primary explosion. prevention of dust explosions on february 7, 2008, a huge explosion and fire occurred at the imperial sugar refinery northwest of savannah, georgia, causing 14 deaths and injuring 38 others, including 14 with serious and life-threatening burns. the explosion was fueled by massive accumulations of combustible sugar dust throughout the packaging building. video watch this dust explosion at imperial sugar. identify the potential ignition sources. case study: imperial sugar case study potential ignition source: an overheated bearing in the steel belt conveyor most likely ignited a primary dust explosion. the primary dust explosion inside the enclosed steel conveyor belt under silos 1 and 2 triggered massive secondary dust explosions and fires throughout the packing buildings read more about the cause of the incident and find additional information here. prevention of dust explosions risk assessment: identify hazards, risks and controls. eliminate dusts at source: example, granular or pastes rather than powders. inerting: nitrogen blankets. dust extraction: minimise fugitive releases. control of ignition sources: zoned areas. correct close close close close close close match the statements to the correct heading and press ‘submit’ when finished. incorrect that is incorrect. please try again. try again try again try again try again try again try again incorrect you did not select the correct response. see answer see answer see answer see answer see answer see answer incorrect correct that's right! you selected the correct response. continue continue continue continue continue continue correct explosion relief venting: directs pressure to a safe location; minimised damage. explosion suppression and containment: contain pressure in vessel; suppress explosion using inter media. plant siting and construction: locate in open air or away from occupied areas; build of weak vent panels rather than heavy construction. mitigation of dust explosions 4.1 fire hazards. 4.2 fire and explosion control. 4.3 dust explosions. 4.4 emergency preparedness. element 4: fire and explosion protection purpose of an emergency plan to control and manage response to foreseeable emergencies. development of an emergency plan sometimes a legal requirement (eg mapp). identify possible foreseeable scenarios and response required. select people (on-site and off-site) to develop the plan. determine resources needed. evaluate external emergency response. consider on-site and off-site medical response. identify if an off-site plan is needed. activity what foreseeable scenarios might your organisation need to cover? learner activity think about this and complete the activity on the next slide before progressing. complete close close close close close close click the icon below to download your reflection as a document file and save this for your own records. download download download download download download sample answer continue >>> continue >>> continue >>> continue >>> continue >>> continue >>> some points to consider: first aid medical incident (an event requiring more than first aid, for installations without ready access to the emergency services) fire or explosion loss of containment (chemical spillage) bomb threat or terrorism outbreak of disease or illness (e.g. norovirus within a closed community such as on an oil rig) flooding or adverse weather event scroll to view answer what foreseeable scenarios might yourorganisation need to cover? type your text here… continue >>> continue >>> continue >>> continue >>> continue >>> continue >>> foreseeable emergencies depending on the organisation first aid/medical. fire/explosion. loss of containment/toxic release. bomb threat/terrorist incident. outbreak of disease. flooding or adverse weather. specialists to develop the plan on-site engineers. workers (process experts). specialists (health and safety, etc.). off-site regulators. local authorities and councils. water companies and authorities. utility companies. emergency services including the police and fire service. activity you are establishing the on-site emergency plan for a chemical site. what resources do you think you might need to enable an effective emergency response? learner activity think about this and complete the activity on the next slide before progressing. resources for effective emergency response resources for effective emergency response close close close close close close the statement highlighted in red is false resources emergency control room. emergency control room. first aid equipment. first aid equipment. aed and evacuation chair. aed and evacuation chair. safe system of work. safe system of work. correct incorrect that is incorrect. please try again. try again try again try again try again try again try again incorrect you did not select the correct response. see answer see answer see answer see answer see answer see answer incorrect that's right! you selected the false statement. continue continue continue continue continue continue correct resources emergency control room. emergency control room. emergency control room. emergency control room. first aid equipment. first aid equipment. first aid equipment. first aid equipment. aed and evacuation chair. aed and evacuation chair. aed and evacuation chair. aed and evacuation chair. safe system of work. safe system of work. safe system of work. safe system of work. resources for effective emergency response resources for effective emergency response which statement is false? submit submit submit submit submit submit resources for effective emergency response resources for effective emergency response close close close close close close resources spill response kits. spill response kits. telephone and radios. telephone and radios. site maps and drain plans. site maps and drain plans. enterprise management software enterprise management software the statement highlighted in red is false correct incorrect that is incorrect. please try again. try again try again try again try again try again try again incorrect you did not select the correct response. see answer see answer see answer see answer see answer see answer incorrect that's right! you selected the false statement. continue continue continue continue continue continue correct resources spill response kits. emergency control room. emergency control room. spill response kits. telephone and radios. spill response kits. spill response kits. telephone and radios. site maps and drain plans. telephone and radios. telephone and radios. site maps and drain plans. enterprise management software. site maps and drain plans. site maps and drain plans. enterprise management software. resources for effective emergency response resources for effective emergency response which statement is false? submit submit submit submit submit submit resources for effective emergency response resources for effective emergency response close close close close close close resources safety data sheets. safety data sheets. computer and printer. computer and printer. staff training room. staff training room. the statement highlighted in red is false correct incorrect that is incorrect. please try again. try again try again try again try again try again try again incorrect you did not select the correct response. see answer see answer see answer see answer see answer see answer incorrect that's right! you selected the false statement. continue continue continue continue continue continue correct resources safety data sheets. safety data sheets. safety data sheets. safety data sheets. computer and printer. computer and printer. computer and printer. computer and printer. staff training room. staff training room. staff training room. staff training room. resources for effective emergency response resources for effective emergency response which statement is false? submit submit submit submit submit submit resources examples telephone and radios. site maps and drain plans. safety data sheets. computer and printer. examples emergency control room. first aid equipment. aed and evacuation chair. spill response kits. spill response kits. availability of external emergency response (including medical) on-site emergency first aid usually adequate. may need additional response if: specialist hazards, eg chemicals isolated location; long response times. on-site and off-site plans on-site and off-site plans may be required in law: on-site developed and managed by the organisation; off-site developed and managed (and implemented) by the authorities. content of an emergency plan depending on legal requirements but to include: systems for alerting and warning workers on site, neighbouring facilities and emergency services; responsibilities in the event of an emergency; expertise of teams involved in response (internal and external); evacuation/shelter arrangements; emergency shutdown of plant and services; consideration of vulnerable people; systems for accounting for workers. information management and media liaison information and communications real time information about the incident: chronological log. hazard information. casualty information. external reports to regulators. media liaison: need media training; usually a prepared statement. theoretical training tabletop exercises trainer-led exercise. carried out in accelerated time. discuss possible actions. respond ‘in theory’. identify deficiencies. competency of response team and commanders incident commanders need: leadership experience; knowledge of plant; good communications skills. team members: part of the site experience. practical skills: first aid, fire-fighting, rescue, etc. practical testing of response fire/emergency evacuation drill: trigger alarm; test workers and response team, eg roll-call and fire wardens. response team drill: practical mock-up scenarios; led by trainer; test actual response; full-site response drill: full-site evacuation and test. question: when did you last hold an emergency drill on site? what did it involve? what conclusions were drawn and what action was taken as a result? provision of information to the public during normal operations potential incidents. possible alarms. action to be taken. during an incident information on the event. action to be taken. may be assisted by authorities. correct close close close close close close a place in which an explosive atmosphere in the form of a cloud of flammable gas in air is likely to occur in normal operation occasionally. a place in which an explosive atmosphere in the form of a cloud of flammable gas in air is likely to occur in normal operation occasionally. a place in which an explosive atmosphere in the form of a cloud of flammable gas in air is likely to occur in normal operation occasionally. a place in which an explosive atmosphere in the form of a cloud of flammable gas in air is likely to occur in normal operation occasionally. a place in which an explosive atmosphere in the form of a cloud of flammable gas in air is likely to occur in normal operation occasionally. a place in which an explosive atmosphere in the form of a cloud of flammable gas in air is likely to occur in normal operation occasionally. learning check - quiz q1 which of the following best describes a zone 1 hazardous area? incorrect that is incorrect. please try again. try again try again try again try again try again try again incorrect you did not select the correct response. see answer see answer see answer see answer see answer see answer incorrect correct that's right! you selected the correct response. continue continue continue continue continue continue correct q1. which of the following best describes a zone 1 hazardous area? a place in which an explosive mixture in the form of a cloud of combustible dust in air is likely to occur in normal operation occasionally. a place in which an explosive mixture in the form of a cloud of combustible dust in air is likely to occur in normal operation occasionally. a place in which an explosive mixture in the form of a cloud of combustible dust in air is likely to occur in normal operation occasionally. a place in which an explosive mixture in the form of a cloud of combustible dust in air is likely to occur in normal operation occasionally. a place in which an explosive mixture in the form of a cloud of combustible dust in air is likely to occur in normal operation occasionally. a place in which an explosive mixture in the form of a cloud of combustible dust in air is likely to occur in normal operation occasionally. a place in which an explosive atmosphere in the form of a cloud of flammable gas in air is likely to occur in normal operation occasionally. a place in which an explosive atmosphere in the form of a cloud of flammable gas in air is likely to occur in normal operation occasionally. a place in which an explosive atmosphere in the form of a cloud of flammable gas in air is likely to occur in normal operation occasionally. a place in which an explosive atmosphere in the form of a cloud of flammable gas in air is likely to occur in normal operation occasionally. a place in which an explosive atmosphere in the form of a cloud of flammable gas in air is likely to occur in normal operation occasionally. a place in which an explosive atmosphere in the form of a cloud of flammable gas in air is likely to occur in normal operation occasionally. a place in which an explosive atmosphere in the form of a cloud of combustible dust in air is not likely to occur in normal operation, but if it does occur, will persist for a short period only. a place in which an explosive atmosphere in the form of a cloud of combustible dust in air is not likely to occur in normal operation, but if it does occur, will persist for a short period only. a place in which an explosive atmosphere in the form of a cloud of combustible dust in air is not likely to occur in normal operation, but if it does occur, will persist for a short period only. a place in which an explosive atmosphere in the form of a cloud of combustible dust in air is not likely to occur in normal operation, but if it does occur, will persist for a short period only. a place in which an explosive atmosphere in the form of a cloud of combustible dust in air is not likely to occur in normal operation, but if it does occur, will persist for a short period only. a place in which an explosive atmosphere in the form of a cloud of combustible dust in air is not likely to occur in normal operation, but if it does occur, will persist for a short period only. quiz submit submit submit submit submit submit q2. consider the scenario below and answer the question on the next slide. an external fire directly heats a vessel containing a flammable liquid. the liquid begins to boil, increasing the pressure which opens an integral pressure relief valve. the liquid level inside the vessel lowers and the fire now begins to heat the vessel above the liquid level. the vessel metal thins, weakens and ruptures. quiz correct close close close close close close a boiling liquid expanding vapour explosion. a boiling liquid expanding vapour explosion. a boiling liquid expanding vapour explosion. a boiling liquid expanding vapour explosion. a boiling liquid expanding vapour explosion. a boiling liquid expanding vapour explosion. learning check - quiz q2 think about the scenario on the previous slide. what type of explosion does this describe? incorrect that is incorrect. please try again. try again try again try again try again try again try again incorrect you did not select the correct response. see answer see answer see answer see answer see answer see answer incorrect correct that's right! you selected the correct response. continue continue continue continue continue continue correct q2. think about the scenario on the previous slide. what type of explosion does this describe? a confined vapour cloud explosion. a confined vapour cloud explosion. a confined vapour cloud explosion. a confined vapour cloud explosion. a confined vapour cloud explosion. a confined vapour cloud explosion. a secondary explosion. a secondary explosion. a secondary explosion. a secondary explosion. a secondary explosion. a secondary explosion. a boiling liquid expanding vapour explosion. a boiling liquid expanding vapour explosion. a boiling liquid expanding vapour explosion. a boiling liquid expanding vapour explosion. a boiling liquid expanding vapour explosion. a boiling liquid expanding vapour explosion. an unconfined vapour cloud explosion an unconfined vapour cloud explosion an unconfined vapour cloud explosion an unconfined vapour cloud explosion an unconfined vapour cloud explosion an unconfined vapour cloud explosion quiz submit submit submit submit submit submit correct close close close close close close on-site and off-site. on-site and off-site. on-site and off-site. on-site and off-site. on-site and off-site. on-site and off-site. learning check - quiz q3. development of an emergency plan should consider areas that are: incorrect that is incorrect. please try again. try again try again try again try again try again try again incorrect you did not select the correct response. see answer see answer see answer see answer see answer see answer incorrect correct that's right! you selected the correct response. continue continue continue continue continue continue correct q3. development of an emergency plan should consider areas that are: on-site only. on-site only. on-site only. on-site only. on-site only. on-site only. either on-site or off-site. either on-site or off-site. either on-site or off-site. either on-site or off-site. either on-site or off-site. either on-site or off-site. off-site only. off-site only. off-site only. off-site only. off-site only. off-site only. on-site and off-site. on-site and off-site. on-site and off-site. on-site and off-site. on-site and off-site. on-site and off-site. quiz submit submit submit submit submit submit correct close close close close close close carbon dioxide. carbon dioxide. carbon dioxide. carbon dioxide. carbon dioxide. carbon dioxide. learning check - quiz q4 which is the preferred fire extinguishing media in a typical process control room? incorrect that is incorrect. please try again. try again try again try again try again try again try again incorrect you did not select the correct response. see answer see answer see answer see answer see answer see answer incorrect correct that's right! you selected the correct response. continue continue continue continue continue continue correct q4. which is the preferred fire extinguishing media in a typical process control room? chemical powder. chemical powder. chemical powder. chemical powder. chemical powder. chemical powder. foam deluge foam deluge foam deluge foam deluge foam deluge foam deluge carbon dioxide. carbon dioxide. carbon dioxide. carbon dioxide. carbon dioxide. carbon dioxide. water deluge. water deluge. water deluge. water deluge. water deluge. water deluge. quiz submit submit submit submit submit submit correct close close close close close close dust on surfaces can be disturbed by a primary explosion causing a larger secondary explosion. dust on surfaces can be disturbed by a primary explosion causing a larger secondary explosion. dust on surfaces can be disturbed by a primary explosion causing a larger secondary explosion. dust on surfaces can be disturbed by a primary explosion causing a larger secondary explosion. dust on surfaces can be disturbed by a primary explosion causing a larger secondary explosion. dust on surfaces can be disturbed by a primary explosion causing a larger secondary explosion. learning check - quiz q5. in processes that involve combustible dusts, why is it especially important to maintain good housekeeping? incorrect that is incorrect. please try again. try again try again try again try again try again try again incorrect you did not select the correct response. see answer see answer see answer see answer see answer see answer incorrect correct that's right! you selected the correct response. continue continue continue continue continue continue correct q5. in processes that involve combustible dusts, why is it especially important to maintain good housekeeping? dust can build up on a variety of flat and irregular surfaces which can spontaneously ignite. dust can build up on a variety of flat and irregular surfaces which can spontaneously ignite. dust can build up on a variety of flat and irregular surfaces which can spontaneously ignite. dust can build up on a variety of flat and irregular surfaces which can spontaneously ignite. dust can build up on a variety of flat and irregular surfaces which can spontaneously ignite. dust can build up on a variety of flat and irregular surfaces which can spontaneously ignite. dust on surfaces can be disturbed by a primary explosion causing a larger secondary explosion. dust on surfaces can be disturbed by a primary explosion causing a larger secondary explosion. dust on surfaces can be disturbed by a primary explosion causing a larger secondary explosion. dust on surfaces can be disturbed by a primary explosion causing a larger secondary explosion. dust on surfaces can be disturbed by a primary explosion causing a larger secondary explosion. dust on surfaces can be disturbed by a primary explosion causing a larger secondary explosion. dust build up on surfaces can be clearly seen by visitors and gives a poor image of the company dust build up on surfaces can be clearly seen by visitors and gives a poor image of the company dust build up on surfaces can be clearly seen by visitors and gives a poor image of the company dust build up on surfaces can be clearly seen by visitors and gives a poor image of the company dust build up on surfaces can be clearly seen by visitors and gives a poor image of the company dust build up on surfaces can be clearly seen by visitors and gives a poor image of the company dust will adversely affect limit sensors and proximity switches causing them to malfunction. dust will adversely affect limit sensors and proximity switches causing them to malfunction. dust will adversely affect limit sensors and proximity switches causing them to malfunction. dust will adversely affect limit sensors and proximity switches causing them to malfunction. dust will adversely affect limit sensors and proximity switches causing them to malfunction. dust will adversely affect limit sensors and proximity switches causing them to malfunction. quiz submit submit submit submit submit submit q6. consider the scenario below and answer the question on the next slide. flammable liquid leaked from a storage vessel into the bund which surrounded it. the liquid began to fill the bund. liquid also began to leak through cracks in the bund and flow towards a faulty electrical pump usually used to empty the bund of rain water. within minutes the entire bund was on fire, taking several hours to extinguish. quiz correct close close close close close close pool fire. pool fire. pool fire. pool fire. pool fire. pool fire. learning check - quiz q6 think about the scenario on the previous slide. what is the best description of this type of fire? incorrect that is incorrect. please try again. try again try again try again try again try again try again incorrect you did not select the correct response. see answer see answer see answer see answer see answer see answer incorrect correct that's right! you selected the correct response. continue continue continue continue continue continue correct q6. think about the scenario on the previous slide. what is the best description of this type of fire? jet fire. jet fire. jet fire. jet fire. jet fire. jet fire. pool fire. pool fire. pool fire. pool fire. pool fire. pool fire. flash fire. flash fire. flash fire. flash fire. flash fire. flash fire. secondary fire. secondary fire. secondary fire. secondary fire. secondary fire. secondary fire. quiz submit submit submit submit submit submit element 4: summary 4.1 fire hazards. 4.2 fire and explosion control. 4.3 dust explosions. 4.4 emergency preparedness. end of element 4 <html><textformat leading='6' tabstops='[0, 48, 96, 144]'>Explain that the qualification consists of one unit. Unit PSM1 is divided into 4 elements. </textformat></html> <html><textformat leading='0' tabstops='[0, 48, 96, 144]'>Explain the fire triangle, using the diagram. Follow up with the Learner Activity question.</textformat></html> <html><textformat leading='0' tabstops='[0, 48, 96, 144]'>Describe using the diagram:</textformat><textformat leading='0' tabstops='[0, 48, 96, 144]'>•Lower Flammable limit - below which the fuel/air mixture is too lean to ignite</textformat><textformat leading='0' tabstops='[0, 48, 96, 144]'>•Upper Flammable limit – above which the fuel/air mixture is too rich to ignite</textformat><textformat leading='0' tabstops='[0, 48, 96, 144]'>•Flammable range – in between!</textformat></html> <html><textformat leading='0' tabstops='[0, 48, 96, 144]'>This was intended to show that while leadership is important, the committee does need the opportunity to speak without being shouted down by the chair. While the chair was quiet, she exerted pressure and the one sensible suggestion was discounted.</textformat></html> <html><textformat leading='0' tabstops='[0, 48, 96, 144]'>Learn more: https://www.hse.gov.uk/fireandexplosion/acetylene-research.htm</textformat></html> <html><textformat leading='0' tabstops='[0, 48, 96, 144]'>In the process industry, BLEVEs are most commonly associated with flammable liquids – but BLEVEs can also occur with non-flammable liquids.</textformat><textformat leading='0' tabstops='[0, 48, 96, 144]'></textformat><textformat leading='0' tabstops='[0, 48, 96, 144]'>Simplified sequence (there are some variations to this depending on liquid fill level, temperature, pressure relief valve (PRV) etc):</textformat><textformat leading='0' tabstops='[0, 24, 48, 96, 144]'>1.Direct flame external heating of tank (e.g. an existing jet fire attacking the tank)</textformat><textformat leading='0' tabstops='[0, 24, 48, 96, 144]'>2.The tank walls heat up – the walls above the liquid level heat up first (the parts in direct contact with the liquid inside heat up more slowly than the parts in contact with the vapour – due to the cooling effect of the liquid)</textformat><textformat leading='0' tabstops='[0, 24, 48, 96, 144]'>3.The liquid starts to boil inside (as the temperature continues to rise)</textformat><textformat leading='0' tabstops='[0, 24, 48, 96, 144]'>4.Pressure rises and the pressure relief valve (PRV) operates to halt the pressure rise (allowing escape of some vapour)</textformat><textformat leading='0' tabstops='[0, 24, 48, 96, 144]'>5.Continuing temperature rise of the vessel walls (the ones in contact with the vapour) causes vessel weakening</textformat><textformat leading='0' tabstops='[0, 24, 48, 96, 144]'>6.Crack begins to appear in the vessel wall</textformat><textformat leading='0' tabstops='[0, 24, 48, 96, 144]'>7.Crack suddenly gets much bigger – total loss of containment (catastrophic failure which has sometimes been described as ‘unzipping of the vessel’)</textformat><textformat leading='0' tabstops='[0, 24, 48, 96, 144]'>8.Rapid depressurisation (sudden release of pressure from loss of containment) causes the superheated boiling contents to suddenly form a rapidly expanding cloud of fine droplets</textformat><textformat leading='0' tabstops='[0, 24, 48, 96, 144]'>9.Fireball develops (ignited by the existing fire)</textformat></html> <html><textformat leading='0' tabstops='[0, 48, 96, 144]'>This was intended to show that while leadership is important, the committee does need the opportunity to speak without being shouted down by the chair. While the chair was quiet, she exerted pressure and the one sensible suggestion was discounted.</textformat></html> <html><textformat leading='0' tabstops='[0, 48, 96, 144]'>Image from unit C</textformat></html> <html><textformat leading='0' tabstops='[0, 48, 96, 144]'>Discuss based on the hazard profile of the companies</textformat><textformat leading='0' tabstops='[0, 48, 96, 144]'>The list in the book contains:</textformat><textformat leading='0' tabstops='[0, 48, 96, 144]'>First aid</textformat><textformat leading='0' tabstops='[0, 48, 96, 144]'>Medical incident (an event requiring more than first aid, for installations without ready access to the emergency services)</textformat><textformat leading='0' tabstops='[0, 48, 96, 144]'>Fire or explosion</textformat><textformat leading='0' tabstops='[0, 48, 96, 144]'>Loss of containment (chemical spillage)</textformat><textformat leading='0' tabstops='[0, 48, 96, 144]'>Bomb threat or terrorism</textformat><textformat leading='0' tabstops='[0, 48, 96, 144]'>Outbreak of disease or illness (e.g. norovirus within a closed community such as on an oil rig)</textformat><textformat leading='0' tabstops='[0, 48, 96, 144]'>Flooding or adverse weather event</textformat></html> <html><textformat leading='0' tabstops='[0, 48, 96, 144]'>Conditions needed:</textformat><textformat leading='0' tabstops='[0, 48, 96, 144]'>•Oxygen</textformat><textformat leading='0' tabstops='[0, 48, 96, 144]'>•Ignition source e.g. Spark of sufficient energy</textformat><textformat leading='0' tabstops='[0, 48, 96, 144]'>• Fuel (Combustible dust – but humidity affects this too)</textformat><textformat leading='0' tabstops='[0, 48, 96, 144]'>•Confinement within hopper, silo, room etc.</textformat><textformat leading='0' tabstops='[0, 48, 96, 144]'>• Dispersion of the dust (sufficiently fine (particle size) to form a cloud in the right concentration range in air)</textformat></html> <html><textformat leading='0' tabstops='[0, 48, 96, 144]'>This was intended to show that while leadership is important, the committee does need the opportunity to speak without being shouted down by the chair. While the chair was quiet, she exerted pressure and the one sensible suggestion was discounted.</textformat></html> <html><textformat leading='0' tabstops='[0, 48, 96, 144]'>More detail on following slides</textformat></html> <html><textformat leading='0' tabstops='[0, 48, 96, 144]'>Discuss based on the hazard profile of the companies</textformat><textformat leading='0' tabstops='[0, 48, 96, 144]'>The list in the book contains:</textformat><textformat leading='0' tabstops='[0, 48, 96, 144]'>First aid</textformat><textformat leading='0' tabstops='[0, 48, 96, 144]'>Medical incident (an event requiring more than first aid, for installations without ready access to the emergency services)</textformat><textformat leading='0' tabstops='[0, 48, 96, 144]'>Fire or explosion</textformat><textformat leading='0' tabstops='[0, 48, 96, 144]'>Loss of containment (chemical spillage)</textformat><textformat leading='0' tabstops='[0, 48, 96, 144]'>Bomb threat or terrorism</textformat><textformat leading='0' tabstops='[0, 48, 96, 144]'>Outbreak of disease or illness (e.g. norovirus within a closed community such as on an oil rig)</textformat><textformat leading='0' tabstops='[0, 48, 96, 144]'>Flooding or adverse weather event</textformat></html> <html><textformat leading='0' tabstops='[0, 48, 96, 144]'>AED = Automated External Defibrillators</textformat></html> <html><textformat leading='6' tabstops='[0, 48, 96, 144]'>For example, routing of a nitrogen fed control pipe work to a control room may expose the operators to an oxygen reduced atmosphere if there is a fugitive leak (actual case).</textformat></html> ALARP means that the risk hasn’t just been reduced, but is now at the lowest level that can be achieved without incurring disproportionate costs (costs can be financial, time, effort and inconvenience). An item of equipment or an area of production plant. The ability of an asset to perform its required function effectively and efficiently whilst protecting health, safety and the environment. Controls that can be put in place between the initiator (the triggering event) to either prevent if from happening or to mitigate the outcome. Also see Bow-Tie model and Hazard realisation. Used with ‘hazard realisation’. As the hazard realisation is worked through then ‘barriers’ can be identified that can be placed between the initiator (the triggering event) to either prevent it from happening or to mitigate the outcome (also known as layers of protection or defence. When these are drawn together this is known as a bow-tie. Hazardous places are classified in terms of zones on the basis of the frequency and duration of the occurrence of an explosive atmosphere: Zones 0-2 relate to gas/vapours/mists and Zones 20-22 to dusts. The ability to undertake responsibilities and to perform activities to a relevant standard, as necessary, to ensure process safety and prevent major accidents. Competence is a combination of knowledge skills and experience and requires a willingness and reliability that work activities will be undertaken in accordance with agreed standards, rules and procedures. A contractor is anyone you get in to work for you who is not an employee. A reaction is called endothermic if energy (heat) is absorbed during the reaction. Used to evaluate the mitigation measures that will operate after an event. The process starts with an initiating event and works forward in time to see what protective measure will operate. Each control will either be a success or a failure and, in this way, branches are built up on tree. A reaction is called exothermic if energy (heat) is released during the reaction. One or more deliberate points of weakness are included in process plant; it they are of suitable size and in the right place, they will safely vent an explosion with the plant. A substance has the risk of exploding in the right mixture with oxygen and if sufficient energy is available. A study often used to brainstorm how a component or a system might fail, the potential effects/consequences of those failures, existing safeguards against those failure modes and whether more should be in place. The property of a substance (usually gas or liquid (or the vapour above the liquid)) to ignite when sufficient energy is applied in the form of heat. The minimum temperature at which a liquid, under specific test conditions, gives off sufficient flammable vapour to ignite momentarily on the application of an ignition source. An advanced risk assessment. It is a very thorough analysis of a process to identify ways in which the process could deviate from its design intention in order that controls can be developed. It is usually chaired by an independent HAZOP leader and involves a multidisciplinary team of designers, engineers, safety professionals, operators and other specialists. A brainstorming activity to identify hazards before changes are made to existing processes and plant (sometimes called a walk-through). In hazard realisation, the assessor looks at ‘the worst-case scenario’ to understand the potential consequences of the hazard so that controls can be implemented in the form of barriers. Reactive measures that look at failures such as the number of injuries, near misses and spills which are reported, or excursions where plant is operated outside of the intended operational envelope. Proactive measurements of conditions that monitor process safety management before something goes wrong and to see if things are operating as intended. The minimum concentration of vapour in air below which propagation of a flame will not occur in the presence of an ignition source. Also referred to as the lowerflammable limit or lower explosive limit. The property of a substance to readily accept electrons from another substance. A formal recorded process used to control work which is identified as potentially hazardous. It is also a means of communication between site/installation management, plant supervisors and operators and those who carry out the hazardous work. Any activity involving a highly hazardous chemical including use, storage, manufacturing, handling, or the on-site movement of such chemicals, or combination of these activities. Any group of vessels that are interconnected, & Separate vessels which are located such that a highly hazardous chemical could be involved in a potential release. The above all considered a single process. A blend of engineering and management skills focused on preventing catastrophic accidents and near misses, particularly structural collapse, explosions, fires and toxic releases associated with loss of containment of energy or dangerous substances such as chemicals and petroleum products. These engineering and management skills exceed those required for managing workplace safety (Adapted from Centre for Chemical Process Safety of the American Institute of Chemical Engineers) The limits of the operating conditions under which a process can take place safely. Typically, process limits are established by setting upper and lower levels for a range of parameters. A document step-by-step instruction on how to conduct specific parts of the operating process. It sets out the way a certain task or activity is done so that mistakes which might lead to a situation where the safe operating envelope could be breached are avoided. The overall purpose of the SOP is to identify and maintain the operating parameters such as pressure limits, temperature range, flow rates etc at the required safe level. The terms used to describe the transfer of information between a shift who are leaving work and incoming new shift. A reaction that is out of control because the rate of heat generation by an exothermic chemical reaction exceeds the rate of cooling available. The maximum concentration of vapour in air above which the propagation of a flame will not occur. Also referred to as the upper flammable limit or the upper explosion limit. In ‘what-if analysis of risk realisation, the assessor asks, 'what-if' and then digs deeper to look at the true potential of an incident.