1. Chapter 7 Fire and Explosions

2. Fires, Explosions, and Detonations
The lowest temperature at which an air-hydrocarbon mixture will explode or burn is called the ignition temperature
A detonation wave for air-hydrocarbon mixtures expands at 4,000 to 8,000 fps

3. Chemical Explosions
A rapidly building, self-contained fire that generates gases and vapors capable of exceeding the pressure ratings of the equipment it is in.
Thermal explosions, combustion explosions, condensed phase explosions, physical explosions, and nuclear explosions.
Thermal explosions are the most common explosions in the chemical industry

4. Figure 7-1 Evolution of a Detonation

5. Texas City Fire and Explosion
April 16, 1947
One of the worst industrial accidents to occur in the U.S.
The S.S. Grandcamp was carrying ammonium nitrate
It killed 581 bystanders, the ships crew, and volunteer firefighters
It knocked two airplanes out of the air
Approximately 880 tons of ammonium nitrate had exploded

6. Phillips and Arco Explosions
In 1980 the CPI began the process of integrating new technology.
The new technology allowed for a smaller workforce
With less skilled workers and new technology to learn safety began to lag
Contract labor began to perform work in plants
Chemical hazards were not regulated
Prevention of catastrophic release was not regulated

7. On Oct employees at Phillips were asked to remove a polyethylene blockage. They refused and the jobs was given to contract workers.
85,000 lbs. of high-pressure gases were dumped from the reactor system.
The explosion killed 23 workers and the entire plant was destroyed.
The explosion registered a 3.5 on the Richter scale.

8. On July 5, 1990 ARCO was having trouble with a safety system on a wastewater tank.
When the tank exploded it killed 17 men.
The Phillips and ARCO incidents led directly to the development of the PSM standard.
An industrial partnership was formed between education, government, and industry.

9. Polymers and Fires
Polymers are natural or synthetic compounds linked together in long chains.
When polymers burn:
Temperatures in an enclosed room will reach over 1,500°F.
Toxic fumes fill the room. Oxygen levels can drop below 10%.
The best protection is a self-contained breathing apparatus.

10. Flammable and Explosive Materials
Fire is a chemical process that requires fuel, heat, and oxygen in the correct proportions to chemically react together.
Chemicals with flashpoints below 100°F are flammable substances.
Burnable material with flashpoints above 100°F are referred to as combustibles.

11. Radiation Hazards
Radiation sickness occurs when a person is exposed to harmful radiation, and the individual cells in the body begin to break down.
The tern distance refers to the drop-off of radiation, because radiation drops off with square of the distance of one foot of the source.

12. Fundamentals of Fire Prevention, Protection, and Control
Analyze the physical layout of the plant and surrounding structures.
Ensure that firefighting equipment is available and strategically placed.
Develop structured safety training programs.

13. Figure 7-7 The Fire Triangle

14. The Chemistry of Fire
It is important to be constantly aware of the following:
Ingredients of a fire
Fire prevention and control measures
Properties of flammable and combustible materials
The effects of absorbed heat include an increase in volume, temperature, change of state, chemical change, and electrical transfer.

15. Correct steps in reporting a fire
Give name and phone number
Give fire location and extent of fire
Give products involved in fire

16. The Hazards of Air Combustion Compression Absorption
Concentrating oxygen
Separation
Mixing
Oxidation

17. Fire Stages
Incipient Stage
Smoldering Stage
Flame Stage
Heat Stage

18. Ignition Temperature
The ignition temperature is described as the lowest temperature at which a substance will automatically ignite. This process does not require a flame to occur. If the mixture is within its flammability limits and has reached its ignition temperature it will ignite.

19. Fire Classification System
Class A fires involve combustible material such as wood, paper or plastic.
Class B fires involve combustible and flammable gases and liquids and grease.
Class C fires are categorized as electrical fires.
Class D fires cover combustible metals.

20. Types of Fire Extinguishers
Carbon dioxide extinguishers
Dry chemical fire extinguishers
Foam fire extinguishers
Halon fire extinguishers
Water fire extinguishers

21. Figure 7-8 Carbon Dioxide Fire Extinguisher

22. Figure 7-9 Dry Chemical Fire Extinguishers

23. Figure 7-10 Foam Fire Extinguisher

24. Figure 7-11 Halon Fire Extinguisher

25. Figure 7-12 Water Fire Extinguisher

26. Fire Extinguisher Use Identify the type of material involved.
Select the appropriate fire extinguisher.
Test the extinguisher.
Approach upwind of the fire.
Aim at the base of the flames, using a sweeping motion.
Back away from the fire before the extinguisher is emptied.
NEVER turn your back on a fire.