Chapter 3: Personal Protective Equipment
5
Multiple Choice
1. C (page 92)
2. A (page 72)
3. A (page 88)
4. C (page 86)
5. B (page 89)
6. C (page 103)
7. D (page 76)
8. C (page 72)
9. B (page 92)
10. A (page 83)
11. C (page 94)
12. A (page 84)
13. A (page 91)
14. B (page 112)
15. A (page 86)
16. D (page 82)
17. B (page 72)
18. D (page 89)
19. B (page 90)
20. D (page 83)
Vocabulary
1. Smoke particles: Smoke particles consist of unburned, partially burned, and completely burned substances. These
particles are lifted in the thermal column produced by the fire and are usually readily visible. The completely burned
particles are primarily ash; the unburned and partially burned smoke particles can include a variety of substances. The
concentration of unburned or partially burned particles depends on the amount of oxygen available to fuel the fire.
Many smoke particles are so small they can pass through the natural protective mechanisms of the respiratory system
and enter the lungs. Some are toxic to the body and can result in severe injuries or death if they are inhaled. These
particles also can prove extremely irritating to the eyes and digestive system. (pages 82–83)
2. Oxygen deficiency: Normal outside or room air contains approximately 21 percent oxygen. A decrease in the amount
of oxygen in the air, however, may drastically affect an individual’s ability to function. An atmosphere with an oxygen
concentration of 19.5 percent or less is considered oxygen deficient. If the oxygen level drops below 17 percent,
people can experience disorientation, an inability to control their muscles, and irrational thinking, which can make
escaping a fire much more difficult.
During compartment fires, oxygen deficiency occurs in two ways. First, the fire consumes large quantities of the avail-
able oxygen, thereby decreasing the concentration of oxygen in the atmosphere. Second, the fire produces large quanti-
ties of other gases, which decrease the oxygen concentration by displacing the oxygen that would otherwise be present
inside the compartment. (page 83)
3. National Institute for Occupational Safety and Health (NIOSH): In the United States, the National Institute for
Occupational Safety and Health (NIOSH) sets the design, testing, and certification requirements for SCBA. NIOSH
is a federal agency that researches, develops, and implements occupational safety and health programs. It also
investigates fire fighter fatalities and serious injuries and makes recommendations on how to prevent accidents from
recurring. (page 85)
4. PASS device: A PASS device is designed to help fire fighters locate a downed fire fighter by sending out a loud audible
signal. The device combines an electronic motion sensor with an alarm system. If the user remains motionless for 30
seconds, it will produce a low warning tone before sounding a full alarm. The user can reset the device by moving
during this warning period. A fire fighter in distress also can manually activate this device. (page 92)
5. Supplied-air respirator: A supplied-air respirator (SAR) uses an external source for the breathing air. In this type
of device, a hose line is connected to a breathing-air compressor or to compressed air cylinders located outside
the hazardous area. The user breathes air through the line and exhales through a one-way valve, just as with an
open-circuit SCBA. Although SARs are commonly used in industrial settings, they are not used by fire fighters
for structural firefighting. Hazardous materials teams and confined-space rescue teams sometimes use SARs for
specialized operations. Some fire service SCBA units can be adapted for use as SARs. (page 84)
6. End-of-service-time indicator (EOSTI): NFPA standards require that SCBA include an end-of-service-time indicator
(EOSTI), or low-air alarm. This warning device tells the user that the end of the breathing air supply is approaching.
NFPA 1500 requires that an exit strategy be practiced when the SCBA cylinder pressure is down to 35 percent of its
capacity. This alarm may take the form of a bell or whistle, a vibration, or a flashing LED. SCBAs are required to have
two types of low-air alarms that operate independently of each other and activate different senses. (page 92)
7. Hydrostatic testing: The U.S. Department of Transportation requires hydrostatic testing for SCBA cylinders on a
periodic basis and limits the number of years a cylinder can be used; for example, composite-fiber overwrapped
cylinders must be replaced after 15 years. Hydrostatic testing seeks to identify any defects or damage that might
render the cylinder unsafe. Any cylinder that fails a hydrostatic test should be immediately taken out of service and
cannot be used. (page 112)
8. Cascade system: Cascade systems have several large storage cylinders of compressed breathing air connected by a
high-pressure manifold system. The empty SCBA cylinder is connected to the cascade system, and compressed air is
transferred from the storage tanks to the cylinder. (page 122)