2024 /2025 | © copyright | This work may not be copied for profit gain Excel!
SCBA (Self Contained Breathing Apparatus)
Questions and Correct Answers | Latest
Update
Identify the development of the SCBA
✓ -:- A. Evolution
✓ B. Closed-circuit
✓ C. Open-circuit
Identify the development of the SCBA
A. Evolution
✓ -:- 1. Breathing through beard
✓ 2. Pumping air to a mask
✓ 3. Independent air supply
Identify the development of the SCBA
B. Closed-circuit
✓ -:- 1. Cylinder of compressed air
✓ 2. Regulator and valves
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,2024 /2025 | © copyright | This work may not be copied for profit gain Excel!
Identify the development of the SCBA
C. Open-circuit
✓ -:- 1. Cylinder of oxygen
✓ 2. Filter system
✓ 3. Regulator and valves
Identify the hazardous environments requiring the use of respiratory protection
✓ -:- A. Oxygen deficiency
B. Elevated temperatures / super heated air
C. Smoke
D. Toxic gases
Identify the hazardous environments requiring the use of respiratory protection
A. Oxygen deficiency
✓ -:- 1. Combustion process consumes oxygen
2. Production of toxic gases may displace oxygen
3. Oxygen concentration diluted by other gases during combustion process
4. Physiological effects of reduced oxygen (hypoxia)
2|P a g e | G r a d e A + | 2 0 2 0 2 5
,2024 /2025 | © copyright | This work may not be copied for profit gain Excel!
a. 21% oxygen in air (Normal)
b. 19.5% OSHA and NFPA definition as oxygen deficient
c. 17% oxygen in air
i) Some muscular impairment
ii) Increase in respiratory rate
d. 12 % oxygen in air-Dizziness, headache, rapid fatigue
e. 9% oxygen in air-Unconsciousness
f. 6% or less oxygen in air-Death occurs in minutes from respiratory failure and concurrent
heart failure
Identify the hazardous environments requiring the use of respiratory protection
B. Elevated temperatures / super heated air
✓ -:- 1. Heated air can damage respiratory tract
a. Excessive heat (120-130 degrees)
i) Blood pressure drop
3|P a g e | G r a d e A + | 2 0 2 0 2 5
, 2024 /2025 | © copyright | This work may not be copied for profit gain Excel!
ii) Circulatory failure
b. Inhalation of heated gases
i) Pulmonary edema
ii) Death from asphyxiation
c. Respiratory tissue injury is not immediately reversible with the introduction of fresh, cool
air
Identify the hazardous environments requiring the use of respiratory protection
C. Smoke
✓ -:- 1. Smoke is the product of incomplete combustion
2. Suspended particles provide a means for the condensation of some of the gaseous
products of combustion
3. Some of these particles are lethal; some are irritating
4. Size of particle determines how deeply they will penetrate into the lung
Identify the hazardous environments requiring the use of respiratory protection
4|P a g e | G r a d e A + | 2 0 2 0 2 5
SCBA (Self Contained Breathing Apparatus)
Questions and Correct Answers | Latest
Update
Identify the development of the SCBA
✓ -:- A. Evolution
✓ B. Closed-circuit
✓ C. Open-circuit
Identify the development of the SCBA
A. Evolution
✓ -:- 1. Breathing through beard
✓ 2. Pumping air to a mask
✓ 3. Independent air supply
Identify the development of the SCBA
B. Closed-circuit
✓ -:- 1. Cylinder of compressed air
✓ 2. Regulator and valves
1|P a g e | G r a d e A + | 2 0 2 0 2 5
,2024 /2025 | © copyright | This work may not be copied for profit gain Excel!
Identify the development of the SCBA
C. Open-circuit
✓ -:- 1. Cylinder of oxygen
✓ 2. Filter system
✓ 3. Regulator and valves
Identify the hazardous environments requiring the use of respiratory protection
✓ -:- A. Oxygen deficiency
B. Elevated temperatures / super heated air
C. Smoke
D. Toxic gases
Identify the hazardous environments requiring the use of respiratory protection
A. Oxygen deficiency
✓ -:- 1. Combustion process consumes oxygen
2. Production of toxic gases may displace oxygen
3. Oxygen concentration diluted by other gases during combustion process
4. Physiological effects of reduced oxygen (hypoxia)
2|P a g e | G r a d e A + | 2 0 2 0 2 5
,2024 /2025 | © copyright | This work may not be copied for profit gain Excel!
a. 21% oxygen in air (Normal)
b. 19.5% OSHA and NFPA definition as oxygen deficient
c. 17% oxygen in air
i) Some muscular impairment
ii) Increase in respiratory rate
d. 12 % oxygen in air-Dizziness, headache, rapid fatigue
e. 9% oxygen in air-Unconsciousness
f. 6% or less oxygen in air-Death occurs in minutes from respiratory failure and concurrent
heart failure
Identify the hazardous environments requiring the use of respiratory protection
B. Elevated temperatures / super heated air
✓ -:- 1. Heated air can damage respiratory tract
a. Excessive heat (120-130 degrees)
i) Blood pressure drop
3|P a g e | G r a d e A + | 2 0 2 0 2 5
, 2024 /2025 | © copyright | This work may not be copied for profit gain Excel!
ii) Circulatory failure
b. Inhalation of heated gases
i) Pulmonary edema
ii) Death from asphyxiation
c. Respiratory tissue injury is not immediately reversible with the introduction of fresh, cool
air
Identify the hazardous environments requiring the use of respiratory protection
C. Smoke
✓ -:- 1. Smoke is the product of incomplete combustion
2. Suspended particles provide a means for the condensation of some of the gaseous
products of combustion
3. Some of these particles are lethal; some are irritating
4. Size of particle determines how deeply they will penetrate into the lung
Identify the hazardous environments requiring the use of respiratory protection
4|P a g e | G r a d e A + | 2 0 2 0 2 5
