Chapter 7
Self-Contained Breathing
Apparatus
Introduction
• Failure to use the SCBA properly
can result in injury or death
• Respiratory system extremely
vulnerable
• Fire departments must have a mask
rule
• Wear and use SCBA in IDLH
atmosphere
• SCBA necessary even during
exterior defensive operations
7.2
Figure 7-1 Large volumes of smoke require the use of
SCBA, even for exterior operations as shown here at a
tire storage facility.
7.3
Introduction (cont’d.)
• Any inhaled toxic gas can directly
cause disease of the lung tissue
• One in 12 firefighters is injured in
the line of duty each year
• Smoke inhalation accounts for 18
percent of fatalities
– 21 percent of fireground injuries
7.4
Figure 7-2 These firefighters in full protective equipment,
including SCBA, are ready to begin interior firefighting
operations.
7.5
Conditions Requiring
Respiratory Protection
• Oxygen deficiency
• High temperatures
• Smoke or by-products of
combustion
• Toxic environments
7.6
Oxygen-Deficient
Environments
• Fire consumes oxygen
– Produces toxic gases
– Displace or dilute oxygen
• Oxygen concentrations below 19.5
percent are oxygen-deficient
atmospheres
• Affects on the human body:
– Muscular impairment
– Mental confusion
– Death
7.7
Table 7-1 Effects of Hypoxia (Reduced Oxygen)
7.8
Elevated Temperatures
• Respiratory system sensitive to
temperature
• Air temperatures as low as 165°F can
cause death within 1 minute
• Inhaling gases causes:
– Pulmonary edema
– Asphyxiation
– Long-term damage
• Temperatures in structure fire reach
1000°F
– One unprotected breath will cause death or
severe damage to respiratory system
7.9
Smoke
• Unburned products of combustion,
particles of carbon, tar, associated gases
• Large amounts of gases due to use of
plastics
• Inhalation of small amounts may be fatal
• Four causes of damage by smoke:
–
–
–
–
Asphyxiation
Chemical irritation
Chemical asphyxiation
Any combination of these
7.10
Effects of Toxic Gases
and Toxic Environments
• Combustion produces toxic gases and
irritants
– Affect short- and long-term health
• When combustion products combine may
form lethal toxins
• Some common gases affect circulatory
system
• Commercial occupancies may produce
additional toxins
– Requires higher level of protection
7.11
Table 7-2 Toxic Gases Formed as Products of Combustion
7.12
Carbon Monoxide
• Produced in great quantity during
combustion process: one of most lethal
gases found in a fire
• Colorless and odorless, always present
• Found in homes with defective furnaces,
clogged chimneys
• CO attaches to red blood cells and
prevents oxygen from bonding with
hemoglobin
• Effects are compounded through repeated
exposure
7.13
Table 7-3 Symptoms of Carbon Monoxide Poisoning
7.14
Hydrogen Cyanide
• Colorless and produced by combustion of
natural materials as well as synthetics
• Can be present long before ignition
temperature of material is reached
– Off-gassing or quantitative decomposition
• Difficult to detect in the body
– Very short half-life
• Significantly compounded when combined
with carbon monoxide
7.15
Figure 7-5 The light smoke condition present during
overhaul will contain large amounts of carbon monoxide
and hydrogen cyanide, requiring SCBA protection.
7.16
Legal Requirements for
Self-Contained Breathing
Apparatus Use
• Common sense: use SCBA on
every fire scene
– Start to finish
• Regulations developed for SCBA
use
• Organizations established
regulations and standards
7.17
Title 29 Code of Federal
Regulations, Section 1910.134
• Establishes standards for all entries into
IDLH atmospheres
• April 1998 revision contains requirements
related to interior structural firefighting
– Defines interior structural firefighting as IDLH
• Requires the use of SCBA
• Requirements for complete respiratory
protection program
– Regular medical evaluation
7.18
NFPA 1500: Standard on Fire
Department Occupational Safety
and Health Program
• Authority having jurisdiction (AHJ) must
adopt the standard for the fire department
• Three additional standards:
– NFPA 1404: minimum requirements for
protection programs
– NFPA 1981: design and performance criteria
– NFPA 1982: standards on PASS
7.19
Limitations of Self-Contained
Breathing Apparatus
• Understand limitations to use unit
effectively and safely
• Limitations of the SCBA unit itself
– Size, weight, air supply
• Physiological limitations of the user
7.20
Figure 7-7 Continuous training with SCBA is one of
the keys to effective firefighting operations.
7.21
SCBA Design and Size
• SCBA units ad weight and bulk to PPE
• SCBA cylinder consumed more quickly
than length of time rated for:
– Limits advance into building
– More frequent crew rotations
• Other concerns:
–
–
–
–
Restricted visibility
Added weight and bulk
Firefighter’s voice muffled
Limited air quantity
7.22
Limitations of the SCBA User
• Physical, mental, emotional state
cause usage problems
– Physical limitations: added weight and
bulk
– Physiological limitations
• Lack of confidence in SCBA unit
• Physical stress and anxiety
• Emotional conditions
7.23
Air Supply Management
• Air supply management
–
–
–
–
Must understand air consumption rates
Individual point of no return
Heads up display
10-10-10 rule
• Various methods of breathing take
experimentation on the part of the firefighter
– Use normal breaths and exhale slowly
– Never hold breath
– Controlled breathing is most efficient use of air
7.24
Figure 7-11 An example of an air consumption test.
7.25
Types of Self-Contained
Breathing Apparatus
• Two types of SCBA:
– Open-circuit SCBA
• Exhaled air is vented to outside
atmosphere
• Most common
– Closed-circuit SCBA
• Exhaled air stays in the system for
filtering, cleaning, circulation
• Sometimes used for specialized rescue
incidents
7.26
Open-Circuit Self-Contained
Breathing Apparatus
• Designed and built in accordance
with NIOSH and NFPA standards
• Four basic assembly components:
–
–
–
–
Backpack and harness
Cylinder
Regulator
Face piece assembly
7.27
Figure 7-13 The four components of the open-circuit SCBA
are the backpack/harness, cylinder, regulator, and face piece
assemblies.
7.28
Closed-Circuit Self-Contained
Breathing Apparatus
• Not used for firefighting operations
• Most common use: hazardous materials
incidents
• Air supplies range from 30 minutes to four
hours
• Contain cylinder, filter system, regulator,
and valves
• Clean and filter exhaled breath and add
oxygen
– Air supply duration based on filtering/cleaning
and oxygen capacity of unit
7.29
Open-Circuit Supplied
Air Respirators
• Open-circuit supplied air respirators
(SARs)
– Also called airline respirators
– Remote air supply
• Commonly used for hazardous materials
incidents
– Confined space rescues
• Long-duration of air supply, mobility,
agility
• SCBA escape unit with 510 minutes
7.30
Donning and Doffing SelfContained Breathing Apparatus
• Most common donning procedures:
– Seat-mounted position in the apparatus
– Side compartment on the apparatus
– Storage case
• Refer to manufacturer’s instructions
7.31
General Considerations
• Operational safety checks must be
performed
• Conducted on a daily or regular
basis
– Immediately prior to using the SCBA
unit
• If any component does not operate
properly or is damaged, unit taken
out of service immediately
7.32
Figure 7-23 Firefighters must perform regular checks
of SCBA to ensure the unit’s ability to operate.
7.33
Storage Case
• Two methods to don unit:
– “Over the head”
– “Coat”
– Choice is a matter of personal
preference and training
• Refer to donning instructions for the
particular SCBA unit
7.34
Seat-Mounted Apparatus
• Allows for quick donning
• Unit readily available for regular
inspection
• Three important safety requirements:
– Storing of the face piece
– Donning the unit while vehicle is moving
– Checking the cylinder gauge
• Never don while vehicle is in motion
• Check gauge before response or use the
buddy system
7.35
Compartment or Side-Mounted
Apparatus
• Similar to seat-mounted position
except firefighter is standing
• If mount bracket wrong height, use
“coat” method
• Follow donning methods for particular
mounting style
7.36
Donning the SCBA Face Piece
• Most SCBA face pieces donned in a similar
manner
– Difference in style of head straps, regulator
location
• Essential to protect firefighter from toxic
gases
• Firefighter must be fitted for the face piece
to be used with a particular manufacturer’s
SCBA
• Prohibit anything that may interfere with
proper fit and seal of face piece
– Examples: eye glasses, beards, sideburns
7.37
Removing/Doffing the
SCBA Unit
• Generally to remove SCBA donning
procedure is reversed
• If awaiting another assignment, remove
face piece
– Allow normal breathing, conserve air
• Do not wear the mask without air flowing
into it
• Regulator or face piece must not be
contaminated
• After assignment complete, report to
7.38
rehabilitation
Self-Contained Breathing
Apparatus Operation and
Emergency Procedures
• Fire departments must establish
respiratory protection programs
• Firefighters must be proficient in the
safe use of SCBA
– Donning and doffing procedures
– Individual limitations
– Limitations of SCBA unit
7.39
Safe Use of SCBA
• Essential to firefighter survival
• SCBA unit and protective
equipment add weight and bulk
– Increased exertion and loss of body
fluids
• Firefighters must be aware of
symptoms of heat stress
– Be aware of own limitations and
abilities
7.40
Operating in a Hostile
Environment
• General rules:
– Check in with accountability officer when
entering or exiting
– Remain low, check the environment and
conditions
– Never remove the face piece, maintain an
awareness of location
– Ventilate as you advance if it does not spread
fire
– Check for outside openings
– Maintain direct contact with other team
members
7.41
– Never enter a hostile environment alone
Restricted Openings
• Probe tight spot with a tool
• Be sure conditions on other side of
obstacle are safe
• Shift pack to left side
• “Swim” through obstacle backwards
• “Forward dive” technique
• Do not remove SCBA unless
absolutely necessary
7.42
Figure 7-31 Firefighters may have to get beneath an
obstacle to facilitate their escape, which may also
require them to lower their profile.
7.43
Emergency Procedures
• Emergency procedures exist to assist a
firefighter in safe escape from hazard
• Remain calm, rely on training and
knowledge
• Never remove the face piece of the SCBA
• Standard emergency check procedure
stressed
• If entangled, do not pull forward
– Use wire cutters to cut one wire at a time
– “Swim” method
7.44
Figure 7-32 Emergency procedures check.
7.45
Inspection and Maintenance of
Self-Contained Breathing
Apparatus
• Inspection on daily or regular basis
• Always follow manufacturer’s
instructions
• Procedures in this chapter may differ
from the recommendation
7.46
Daily Maintenance
• SCBA units should be checked
daily
• If used during emergency scene or
training exercise should be
serviced in same manner
• Follow 10-step inspection
procedure
7.47
Monthly Maintenance
• Monthly SCBA check contains all
elements of the daily check
– Adds several checks of mechanics of
system
• Irregularities noted and repaired or
pull SCBA from service
7.48
Annual and Biannual
Maintenance
• NIOSH and SCBA manufacturers
require different functional tests of
SCBA units
• Only manufacturer’s authorized or
trained service personnel shall
conduct these tests
• Firefighters should refer to the
instructions for the SCBA units used
7.49
Changing SCBA Cylinders
• Cylinders changed after use,
following local SOPs
• Cylinder 90 percent full could mean
loss of 25 minutes of air supply
– Could make the difference in successful
exit
• Follow 12-step replacement
procedure
• Additional steps for two-person
SCBA cylinder replacement
7.50
Servicing SCBA Cylinders
• Cylinder serviced when below full
– Air source must be tested and certified
– All cylinders must have a current
hydrostatic test date
– All fill stations must have fragmentation
containment devices
– All manufacturer’s recommendations
should be followed
– Fill rate may vary
• Cascade system
• Compressor/purifier system
7.51
(A)
(B)
Figure 7-36 (A) A cascade system is one of the systems available
to service SCBA cylinders. These may be fixed or mobile units. (B)
7.52
Lessons Learned
• SCBA unit is to a firefighter as a weapon is
to a soldier
• No substitute for proper SCBA training
– Continued practice and advanced training
necessary
• Prevent failures: thoroughly inspect and
test SCBA function as often as possible
• Firefighters must be prepared to go in
harm’s way
– Be knowledgeable and proficient in use of SCBA
7.53