Vapor Volume Volume of gas formed when a liquid substance evaporates Computed from specific gravity and vapor density 0.829 (SpG) Vapor Volume (m3/liter) = Vapor density Example: What is the vapor volume of a liter of acetone? 0.829 (0.9) Vapor Volume (m3/l) = 2 = m3/l 17ġ8 Vapor Volume What is the probability of forming a combustible mixture if a 4 liter container of acetone is used in a room 3 x 4 x 2.5 m? Volume of the space = 30 m3 Vapor volume = m3/L Vapor volume necessary to form a Combustible mixture: Applying the mixing factor of 5: 2.01 L / 5 = 0.40 L 30 m3 x = 0.75 m3 0.75 m3 0.373 m3/ L = 2.01 L Since it doesn’t take much more than “1 coffee mug” of acetone to form a combustible mixture, the probability appears to be high! 18 Tightness of construction External winds Internal/external temperature Vertical openings Stairways Elevator shafts Ventilation shafts 16 11ġ2 Classes of Flammable and Combustible Liquidsĩ3 Combustible FP > 38C (100✯) IIIA, FP>60C but 38C but 23C but 38C 38 Boiling Point (C) OSHA Office of Training and Education, defined in Fahrenheit 12Ĭommon Name Flash Point (C) CLASS IA CLASS IB CLASS IC Ethyl Ether - 45 Gasoline - 43 Methyl Ethyl Ketone - 6 Toluene 4 Xylene Turpentine 35 OSHA Office of Training and Education 13Ī good plan for safe use of flammable and combustible liquids contains at least these components: Control of ignition sources Proper storage Fire control Safe handling OSHA Office of Training and Education 14 14ġ5 Fire Behavior 816 C – 1260 C Growth Phase Flashoverįully Developed Phase Decay Phase Extinction Incipient Phase Temperature Ignition Time 15ġ6 Fire Behavior Stack Effect Hot expanding gases move vertically Flammable liquids: have flash points below 38✬ are more dangerous than combustible liquids may be ignited at room temperature Combustible liquids: have flash points at or above 38✬ Can pose serious fire and/or explosion hazards when heated OSHA Office of Training and Education 10Ībove UFL/UEL, mixture is too rich to burn Upper Flammability/Explosive Limit (UFL/UEL) Flammability/Explosive Range Lower Flammability/ Explosive Limit (LFL/LEL) Below LFL/LEL, mixture is too lean to burn Defined in terms of the amount of fuel in air. In general, the lower the flash point, the greater the hazard. 8ĩ Fire A fire must have four things to ignite and maintain combustion:įlash Point Flash point: The minimum temperature at which a liquid gives off enough vapor to form an ignitable mixture. This person was trying look inside the tank and lit a match for light to see better.
Smoke cloud & soot Plenty of time to escape 1 min from small to inescapable fire People are killed by the flames #1 killer in fires is CO, not flames Wait to be rescued No! Act to save self Ladders can reach to about 6th floor Can not prepare for a fire Preparation can save your life 6Ĩ Facial Burns Lower photo shows a fuel tank. Get occupants out Minimize property loss and interruption Fire Containment/Suppression 5Ħ Common Myths Fire will light the way out Plenty of time to escape Vehicles, falls, poison, drowning, fire Most dangerous industries from fire hazard: Mines Grain elevators and mills Refineries Chemical plants Leading causes: Electrical Smoking Friction Overheating Hot surfaces 4 Leading causes: Cigarettes Heating/cooling equipment Electrical Matches, lighters, candles 3Ĥ Industrial Fires Fifth leading cause of accidental death Presentation on theme: "Fire Protection and Prevention in Chemical Laboratories"- Presentation transcript:ġ Fire Protection and Prevention in Chemical LaboratoriesĢ Fires Preventable Caused by unsafe practices ControlĮlectrical safety violations Uncontrolled use of flammable and combustible materials Control Inspect, inspect, inspect Educate, educate, educate! 2ģ Home Fires 1 million fires and 8,000 deaths annually in the US