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What is fire?

What is fire?. Definition: A self-sustaining rapid oxidation of a combustible material giving off heat and light. “The Fire Triangle”. Oxygen:. Heat:. Fuel:. “The Fire Tetrahedron”. Uninhibited Chain Reaction:. Oxygen:. Heat:. Fuel:. Methods of Heat Transfer:.

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What is fire?

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  1. What is fire? Definition:A self-sustaining rapid oxidation of a combustible material giving off heat and light.

  2. “The Fire Triangle” Oxygen: Heat: Fuel:

  3. “The Fire Tetrahedron” Uninhibited Chain Reaction: Oxygen: Heat: Fuel:

  4. Methods of Heat Transfer: Radiation: Transfer of heat by energy waves Conduction: Transfer of heat by direct contact or heat conducting mediums Convection: Transfer of heat by air or liquid

  5. Actions to Take Upon Discovery of Smoke or Fire: • Activate the fire alarm. • Notify all occupants. • Notify fire department by 911 and give all pertinent information. • If the fire is contained to it’s original origin, attempt to fight fire with the proper extinguisher.

  6. Which kind of extinguisher should I use? First recognize that there are four different kinds of fires

  7. Fire Types • Class A fires are ordinary materials like burning paper, lumber, cardboard, plastics etc.

  8. Fire Types • Class B fires involve flammable or combustible liquids such as gasoline, kerosene, and common organic solvents used in the laboratory.

  9. Fire Types • Class C fires involve energized electrical equipment, such as appliances, switches, panel boxes, power tools, hot plates and stirrers. Water is a particularly dangerous extinguishing medium for class C fires because of the risk of electrical shock.

  10. Fire Types • Class D fires involve combustible metals, such as magnesium, titanium, potassium and sodium as well as organometallic reagents such as alkyllithiums, Grignards and diethylzinc. These materials burn at high temperatures and will react violently with water or other chemicals. Handle with care!

  11. Fire Types • Some fires may be a combination of these! Your fire extinguishers should have ABC ratings on them. These ratings will often have numbers on them that look something like "3-A: 40-B: C". Higher numbers mean more firefighting power.

  12. Which kind of extinguisher should I use? • Water extinguishers are suitable for class A (paper etc.) fires, but not for class B, C and D such as burning liquids, electrical fires or reactive metal fires. In these cases, the flames will be spread or the hazard made greater!

  13. Which kind of extinguisher should I use? • Dry chemical extinguishers are useful for class ABC fires and is your best all around choice. They have an advantage over CO2 extinguishers in that they leave a blanket of non-flammable material on the extinguished material, which reduces the likelihood of reignition.

  14. Which kind of extinguisher should I use? • CO2 (carbon dioxide) extinguishers are for class B and C fires. They don't work very well on class A fires because the material usually re-ignites. CO2 extinguishers have an advantage over dry chemical in that they leave behind no harmful residue -- a good choice for an electrical fire on a computer or other delicate instrument.

  15. Which kind of extinguisher should I use? • Metal/Sand Extinguishers are for flammable metals (class D fires) and work by simply smothering the fire. You should have an approved class D unit if you are working with flammable metals. • A good choice for flammable metal fires such as Grignard reagents, alkyllithiums, sodium metal, etc.

  16. Inspect Your Extinguisher • Check needle on pressure gauge. • Ensure pin is properly secured. • Check hose for damage. • Check body of cylinder for dents and corrosion. • Check label for certified inspection date.

  17. How to Operate a Fire Extinguisher Remember The Acronym “P.A.S.S.”

  18. How to Operate a Fire Extinguisher Pull the pin. This will allow you to discharge the extinguisher.

  19. How to Operate a Fire Extinguisher Aim at the base of the fire. If you aim at the flames (which is frequently the temptation), the extinguishing agent will fly right through and do no good. You want to hit the fuel

  20. How to Operate a Fire Extinguisher • Squeeze the top handle or lever. • This depresses a button that releases the pressurized extinguishing agent in the extinguisher.

  21. How to Operate a Fire Extinguisher Sweep from side to side, until the fire is completelyout. Start using the extinguisher from a safe distance away, then move forward. Once the fire is out, back out of the area and keep an eye on the area in case it re-ignites.

  22. Safety Practices/Review • Remain Calm • Use the correct extinguisher • Never turn your back to a fire • Account for personnel • Notify fire department

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