Basic Firefighting: SCBA Review

Proper knowledge and use of self-contained breathing apparatus is necessary to help provide a safe working environment for the emergency service provider.

Session Reference:

Topic: Basic Firefighting: SCBA Review

Level of Instruction: 3

Time Required: 3 Hours


• Personal Protective Clothing

• Personal Alert Safety System (PASS) Device

• Self-Contained Breathing Apparatus


• Essentials of Fire Fighting, 4th ed., International Fire Service Training Association

• NFPA 1500

• 29 CFR 19134


Motivation: Instructor should stress the need for safety in all aspects of emergency service duties and impress upon the students the roles of attitude, training, and awareness. Proper knowledge and use of self-contained breathing apparatus is necessary to help provide a safe working environment for the emergency service provider.

Objective (SPO): The student will be able to describe important aspects of safety and demonstrate practical application as it pertains to emergency service provider operations from memory, without assistance, to an accuracy of 70% and the instructor's satisfaction. The student will be able to identify the basic functions and uses of and properly don and doff self-contained breathing apparatus.

Overview: Basic Firefighting: SCBA Review

• Operation, maintenance, inspection, and cleaning

• Donning and doffing procedures and safety check

• Controlled breathing techniques

• Emergency procedures

• Changing cylinders

• Practical exercises

Basic Firefighting: SCBA Review

SPO 1-1 The student will be able to describe important aspects of safety and demonstrate practical application as it pertains to emergency service provider operations from memory, without assistance, to an accuracy of 70% and the instructor's satisfaction. The student will be able to identify the basic functions and uses of and properly don and doff self-contained breathing apparatus.

EO 1-1 For each component of the SCBA, identify its function, safety feature, and limitations.

EO 1-2 Demonstrate and document maintenance for SCBA.

EO 1-3 Demonstrate donning and doffing the SCBA while wearing full protective clothing and ensure that it is ready for safe use (NFPA 1001 (1997) 3-3.1).

EO 1-4 Demonstrate controlled breathing techniques to utilize during work and emergency conditions (NFPA 1001 (1997) 3-3.1).

EO 1-5 Demonstrate proper emergency procedures to use in case the SCBA fails (NFPA 1001 (1997) 3-3.1)

EO 1-6 Demonstrate changing the cylinder on an SCBA assembly (NFPA 1001 (1997) 3-3.1)

EO 1-7 Demonstrate the use of SCBA in the following evolutions (NFPA 1001 (1997) 3-3.1)

• Following a hose line with obstacles and vision obscured.

• Conducting a simulated search of a structure charged with smoke, locating and interrupting utility service, and attacking a simulated fire using a standpipe system.

• Moving in a forward direction and successfully overcoming obstacles to enter and exit a maze.


Instructional Guide

I. Open Circuit/Positive Pressure (1-1)

Method of Operation

• Compressed air from cylinder is supplied to wearer

• Inhalation opens valve in regulator

• Regulator allows air to flow to facepiece

• Exhalation closes valve in regulator, stopping flow and opens exhalation valve in facepiece to atmosphere


• Air from cylinder is allowed to pass through regulator. Upon inhalation, pressure is reduced in facepiece. Regulator supplies more air to compensate for pressure drops. Exhalation valve forced closed by spring tension causing slight pressure buildup inside facepiece

• Maintains slightly higher than atmosphere pressure

• Prevents leaks from outside into facepiece


SCBA Components

• Cylinder

        • Types

             • 30 minute high pressure system

                     • Volume - 45 cu. ft. at 4,500 psi

                     • Cylinder is about half the size of a 30 minute low pressure cylinder, providing

                        small firefighter profile

                     • Average unit weight - 23 lbs.


              • 60 minute high pressure system

                       • Volume - 88 cu. ft. at 4,500 psi

                       • Cylinder is slightly larger than 30 minute low pressure

                       • Average unit weight - 30 lbs.


• Cylinder valve and gauge


• Markings - serial number, hydrostatic test date, DOT markings, fill pressure


• Safety or over-pressure plug - if, during filling, the cylinder is over filled, a small metal disc will rupture and the air will escape to the outside


• A full cylinder rated at 30 minutes by the NIOSH/MSHA (Federal non-fire service agencies) will last about 15 to 20 minutes depending on

                      • Physical condition

                      • Psychological stability or make-up

                      • Ability to control breathing

                      • Training and experience

                      • Work activity

                      • Other factors


• Harness - a device to hold and carry the breathing apparatus assembly on the back

          • Backplate - holds the cylinder in place with a cylinder strap; equipped with

            adjustable band for 30- and 60-minute cylinders

          • Shoulder strap - straps to carry the assembly on the back

          • Chest strap - holds the shoulder straps in position

          • Waist strap - holds the harness on the back and to prevent the assembly from


          • Approval label - NIOSH/MSHA


• Low pressure warning device

          • Device to warn that your air supply is running low

          • Activates at approximately 25% of rated working pressure (3 to 5 minutes) of air

            left in the cylinder, depending on

                     • Physical condition

                     • Psychological stability or make-up

                     • Ability to control breathing

                     • Training and experience

                     • Work activity

                     • Other factors

          • Location and type of device


• High pressure hose

         • Carries air, at cylinder pressure, from cylinder to first and second stage


         • Connector from high pressure hose

                     • Should be finger tight. If the connector still leaks, snug up with hand. If it still

                        leaks, check "O" ring. Never over tighten. It will damage "O" ring

                     • Keep spare "O" rings with apparatus, replace as necessary

                     • Never use wrench, or full hand power on connector


• Regulator assembly - a device which reduces the high pressure air from the cylinder to a lower pressure

             • First stage mounted on side of backpack

             • Gauge - tells how much air is remaining in the cylinder

                     • Connected to high pressure hose and fastened to left shoulder strap

                     • Shows pressure reading whenever pressure on system

                     • Have student compare cylinder and regulator gauge, go by lowest pressure

                     • Should never be more than 100 psi difference. If so, have checked by service



• Facepiece mount regulators

            • No mainline valve - system is activated by purging facepiece and then inhaling

            • Does not have by-pass valve - system is designed to fail in the open position

            • Purge valve - for purging contaminants from the facepiece

            • Donning switch - shuts off air to facepiece prior to doffing

            • Locking device - to assure regulator to facepiece connection

            • Gasket - sealing regulator to facepiece


• Facepiece assembly

            • Facepiece - covers/protects the face and provides for inhalation and exhalation

              of low pressure air

           • Exhalation valve - allows exhaled air to leave the facepiece and stops smoke

             and toxic gases from entering facepiece on inhalation

                    • Can sometimes become stuck, preventing exhaled air leaving by way of the

                      exhalation valve; causes air to blow out around the face seal

                    • To correct, try blowing out hard while holding facepiece tight to face

                    • Positive pressure - exhalation valve on the facepiece is equipped with a pressure

                       balancing mechanism - air does not continuously flow, but does maintain a

                       positive pressure inside the facepiece

           • Speaking diaphragm - allows wearer to communicate more clearly

           • Nose cup - deflects exhalation away from lens to prevent fogging

           • Spider or facepiece harness - strap which holds the facepiece firmly against the

             face. Be sure straps are fully extended when putting away (check for wear and



II. Maintenance and Inspection (1-2)

After Use Maintenance

           • Recharge/replace cylinder if at 90% capacity or less

           • Inspect "O" ring and gasket

           • Inspect facepiece

           • Clean facepiece

                • Submerge in approved cleaner/disinfectant with warm water

                • Rinse in warm water

                • Air dry - do not connect to regulator when low pressure hose is wet

          • Inspect and clean harness

          • Check operation of all gauges and valves


Cylinder Recharging

          • Secure SCBA cylinder in a fragment proof charging station when possible

          • Connect SCBA to cascade high pressure line

          • Open SCBA valve

          • Open cascade valve with the least pressure, but more than the SCBA pressure

                 • Watch gauges

                 • Cascade cylinders will follow a numerical or other predetermined order.

                   Lowest pressure cylinder corresponds with the lowest numbered cylinder

                 • Never open more than one cascade cylinder at a time - this will cause

                 cylinders to equalize

          • Close valve of cascade cylinder when pressure is equal to SCBA

          • Open valve of cascade cylinder with next highest pressure (next in

            predetermined order) and continue procedure until SCBA is fully charged

          • Shut valves

          • Bleed high pressure line

          • Disconnect SCBA - remove from charging station


Recommended Daily Inspection and Maintenance

          • Cylinder pressure

          • High pressure hose coupled to cylinder - should be finger tight

          • Operation of low pressure alarm

                 • Open cylinder valve

                 • Alarm should activate when pressure builds up and stops afterwards

                 • Check gauge on shoulder strap

                 • Alarm - Note pressure at which alarm starts to sound. Should be 1/4 of

                   working pressure and continue until pressure reaches approximately 5 to

                   10% of working pressure

           • Straps fully extended

           • Check complete unit

                  • Cracks

                  • Cuts

                  • Abrasions

                  • Dents

                  • Missing parts

          • Cylinder secured to backplate and harness


Monthly Inspection and Maintenance - same as daily/weekly plus

          • Visually inspect all rubber parts for damage

          • Test cylinder and valves for air tightness with soapy water solution

          • Don and operate unit and check

                  • Airflow

                  • Noises

                  • Gauge readings

                  • Exhalation valve

                  • Anything else the manufacturer recommends


Defective Units

            • Remove from service

            • Tag

            • Repair or replace


Testing Schedule - Hydrostatic

            • Composite - every 3 years

                     • NOTE: As per DOT regulations, 49 CFR 173.34(e), cylinder life on

                       composite cylinders only is restricted to a fixed number of hydrostatic test

                       dates. That number should be five

            • Regulator/high pressure hose assembly must be tested by an approved service

              center every 2-1/2 years



III. Donning and Doffing Procedures/Safety Checks (1-3)

Student Preparation

         • Harness and facepiece - all should be the same

                 • Cylinder up

                 • Cylinder valve at feet

                 • Straighten and extend all straps

                 • Facepiece on right of cylinder

        • Check apparatus to see if the cylinder valve is off and system bled


Pre-Donning Inspection

        • All straps (harness and facepiece)

                  • Take out twists

                  • Fully loosened

        • Valves - all connections hand tight

        • Read cylinder gauge (out loud during drills)

        • Open cylinder valve

              • Listen for low pressure

                         • Will not activate if regulator has not been bled from previous use

                         • Remind students not to use SCBA if warning device does not activate

               • Read regulator gauge and compare to cylinder gauge


Donning (two suggested methods)

          • Coat method

                  • Stand or kneel at valve end of cylinder

                  • With left hand, cross over backplate and grasp shoulder strap that will be

                    worn on left shoulder

                  • Control the regulator (if applicable) with right hand

                  • Lift harness assembly and swing so that grasped shoulder strap is resting on

                    left shoulder while right should strap comes across the back to rest on right


                 • Secure harness

        • Over the head

                • Kneel at the end opposite the cylinder valve

                • Grasp backplate/cylinder with both hands

                • Lift harness assembly overhead - let straps hang free, they will fall into place

                  over the elbows

                • Slide harness onto back in proper position

                • Slide harness according to manufacturer's procedure

         • Don facepiece (five piece webbing)

                • Chin first

                • Place webbing over head

                • Secure straps (in order)

                           • Neck

                           • Temple

                           • Top (if needed)

                • Helmet chin straps must be used

           • Safety check

                   • Facepiece seal

                           • Hold hand over regulator connection on facepiece

                           • Inhale slightly and hold your breath momentarily (10 seconds)

                           • Facepiece should slightly collapse and there should not be any leakage or

                             air. If leak is suspected - readjust facepiece and head straps and retry

                  • Exhalation valve check

                           • With hose in the regulator coupling, inhale and exhale to assure function

                           • Foreign matter may lodge in spring assembly



       • Connect regulator to facepiece according to manufacturer's procedure

       • Inhale to check regulator gauge function. Gauge reading should be equal to or

          within 100 psi. Believe the lessor of the two

       • Positive pressure check - break seal with two fingers; check for outward rush of air

       • Open purge valve to check for function

               NOTE: Make sure that the student's helmet is sitting properly on the head, and

               chin strap is secured.


SCBA Doffing

       • Facepiece doffing

               • Remove regulator from facepiece and secure in holder on waist strap

               • Loosen facepiece spider straps by pulling forward the buckles provided

               • Pull facepiece down so as to allow the chin to be removed, then lift facepiece

                 over head. Finish loosening spider straps as in "ready position"

              • Place in a clean area by right foot so as to protect the lens from scratching

                and the inside of facepiece and breathing tube from becoming wet or

                contaminated from dirt, dust, grit, or liquids

             • Clean facepiece as described by manufacturer or see cleaning and stowing

      • Doffing the harness

            • Unbuckle waist and chest straps

            • Loosen waist strap and fully let out using appropriate buckles. Loosen and let

              out shoulder straps all the way. Remove right shoulder strap from shoulder

            • Reach to left shoulder strap with left hand

            • Slide harness off left shoulder

            • Place harness on floor with cylinder towards floor

            • Extend all straps on the harness assembly

            • Lay out straps and check to see that they are not tangled or twisted; straighten

             as necessary

           • Shut off cylinder and bleed with purge valve

                   NOTE: Upon completion of the last donning and doffing drill, have students remain

                   in SCBA and sit on floor. Have them practice controlled breathing methods as

                   they are described in next section.


Donning Drill

        • Have students spread out in a large circle

        • While in full protective clothing, each student shall don and place their SCBA in

          full operation with 1 1/2 minutes, using the four-step method

                • Procedure: Students shall stand erect with hands above head. Donning and

                  timing starts on the word "go." Students shall kneel or raise one hand in the

                  air to indicate completion of task

              • Instructor should call out time at one minute and each ten second interval

                thereafter until each student has completed task

              • Repeat as necessary


Controlled Breathing Techniques (1-4)

Breathing must be kept on a conscious level. Subconscious patterns result in breathing only through the mouth or nose

         • Nose breathing results in

                   • Short breaths

                   • Lungs not filled to capacity

          • Mouth breathing results in

                  • Rapid breathing

                  • Body cannot take full advantage of oxygen before exhalation


Suggested Patterns

         • In through nose - out through mouth

                • Easy to learn and remember

                • Close to normal pattern when speaking

                • Technique

                          • Breathe in slow and deep

                          • Hold in lungs 3-4 seconds for maximum oxygen/carbon dioxide exchange

           • In through mouth - out through nose

                 • Allows for good air exchange without holding breath

                 • Techniques

                       • Inhale rapid and full

                       • Exhale slowly

                       • Best method for strenuous work


          • Five-second count method

                • Technique

                      • Inhale for 5 seconds using either of first two methods - slowly and fully

                      • Hold for 5 seconds

                      • Exhale for 5 seconds

                      • Hold for 5 seconds

                      • Repeat cycle

               • Best for short rest breaks

         • Skip breathing

              • Emergency only - for conservation of air

              • 30 minute SCBA may be extended to two hours

              • Technique

                     • Inhale fully

                     • Hold breath for normal exhalation time

                     • Take additional breath before exhaling

                     • Exhale slowly

                     • Repeat cycle

             • Important to remain mentally and physically calm


V. Emergency Procedures (1-5)

NOTE:In the course of normal emergency operations, personnel may find themselves in a situation where they may become trapped; run out of air; or experience an equipment malfunction. While there are a number of non approved methods of survival, or buddy breathing and are readily available for reference in several fire service training publications, this outline will target a method of receiving emergency breathing air that is specific to certain brands or models of SCBA.

The instructor should modify this section to suit the purposes of his or her department and should be consistent with departmental procedures.

Quick Fill Procedure

         • Remove quick fill hose from pouch

         • Remove protective caps and connect quick fill hose to male connection near

           regulator on left shoulder strap of donor unit

                • Female connection should snap in place

                • Green ring should appear near female connection

         • Remove protective caps and connect quick fill hose to male connection on receiver

           unit pressure of two cylinders will equalize within one minute

         • Disconnect hose, replace all protective caps, and bleed hose by pressing against

          solid surface, and replace in pouch with connections downward


VI. Changing Cylinders (1-6)

• Spread apparatus out on floor with cylinder up

• Point cylinder valve at feet

• Extend and straighten all straps

• Turn cylinder valve off

• Bleed air off regulator by slowly opening purge valve

• Disconnect H/P hose from cylinder (check "O" ring in H/P connector)

• Loosen cylinder strap or holding device

• Remove cylinder from backplate

• Insert new cylinder to cylinder stop

• Tighten cylinder holding device; securing cylinder to backplate

• Check "O" ring in H/P connector before connecting high pressure hose

• Check proper position of regulator and straps by donning apparatus

• Turn cylinder valve on to check for leaks

• Bleed system as in D and E above



VII. Practical Exercises (1-7)

Obscured Vision Practical Exercise

         • Students are to follow a hoseline going from one end (nozzle to water source or

           water source to nozzle) without losing contact with hoseline or becoming


        • Nomex hoods should be removed until the facepiece is in place. They should then

          be put on backwards so as to obscure vision.

       • Students will be spread on the hoseline at sufficient intervals to avoid working as a


Smoke Environment Practical Exercise

      • Preparation

            • Area divided into rooms with furniture arranged to simulate an actual

              conditions. Connecting door(s) separates rooms

            • Smoke will be produced by smoke machine

            • At least one instructor will be with the students at all times

            • Explain to the students that they will be assigned tasks to perform in the smoke


            • Tasks will be conducted with proper systematic procedures

                     • Team of two

                     • First person to the right and second person to the left

                     • Remind team members to communicate

       • Smoke evolution

              • Student orientation - the exercise is designed to

                     • Expose the student to smoke

                     • Learn to use his/her hands for his/her eyes

                     • Increase the student's confidence in his/her breathing apparatus

                     • Learn to work as a member of a team

                • Assigned team will report to the instructor in charge of smoke evolutions in

                   order of their assigned numbers. Instructor will prepare team to enter smoke

                   area. Accountability tags will be collected prior to entry into smoke area.

                • Each team will appoint a leader who will assign the tasks to be performed

                • All will conduct a systematic search

                • When search is completed, team leader will indicate so and team will exit

                  smoke area

        • Communication will be confined to each assigned task

                 • Have the students call out to the instructor when each task is completed

                 • Have the students guide and direct other team member to their assignments

         • Instructor should insure that

                 • All students stay in smoke area until all tasks are completed

                 • Students exit the smoke area when all tasks are completed to the satisfaction

                   of the instructor

                 • Students function with the complete apparatus on for a few minutes before

                   removing facepiece

          • At the conclusion of the smoke evolution, the student will

                 • Collect accountability tag after the smoke evolution has been completed

                 • Refill the SCBA cylinder

                 • Return the SCBA to its proper place


Maze Evolution

       • Students assemble at entrance of maze area with facepiece in place and regulator

         ready for connection

       • At signal of instructor, next student place accountability tag at designated area and

         enters door to maze

       • Student proceeds through maze in a forward direction, attempting to recognize

          area using hands

        • Any obstacle that is suppose to open will open easily (no forced entry is required)

        • Students exits maze at completion of evolution and retrieves accountability tag

       • Students continue to repeat steps until all have successfully completed.



       • Cleaning: Take a small amount of the cleaning liquid provided and wet the

          material provided for cleaning. Wipe out the inside of the facepiece to remove all

          sweat and other foreign materials. Allow to dry. Check once again to be certain

          that all foreign material has been removed and that the inside of the facepiece is

          dry. Check the cleanliness of the regulator connector, the regulator, and the

          exhalation valve for dirt and other foreign material and clean as necessary.

       • Stowing Apparatus: After changing the cylinder, ensure that the cylinder is filled

         and that all straps are extended.

       • Stowing must be done under the supervision of an instructor.

       • Instructor should critique the whole class

              • After all equipment has been stowed, assemble students in appropriate area

              • An overall review of the class and individual student's performance, should be

                made by each instructor. Comments should be made on strong points and weak

                points. Weak points should include:

                     • Donning and doffing proficiency

                     • Controlled breathing

                     • Psychological comfort (discomfort) while wearing breathing apparatus in a

                       smokey atmosphere

                      • Inability to recognize objects by feel

                      • Teamwork




Basic Firefighting: SCBA Review

• Operation, maintenance, inspection, and cleaning

• Donning and doffing procedures and safety check

• Controlled breathing techniques

• Emergency procedures

• Changing cylinders

• Practical exercises




Practical Skills Checklist

Student _________________________________

Donning SCBA

____ a. Turn cylinder on

____ b. Check low pressure warning bell

____ c. SCBA on properly (cylinder gauge down, straps secured)

____ d. Facepiece seal check

____ e. Donning SCBA within 1 minute

Follow hoseline with vision obscured

____ a. No unusual breathing difficulty

____ b. Did not get disoriented

____ c. Maintained forward progress

____ d. Recognize couplings and direction

Smoke evolution

____ a. Work as a team and performed assigned duties

____ b. No unusual breathing difficulty

____ c. Did not get disoriented

Maze evolution

____ a. Maintained forward direction

____ b. No unusual breathing difficulty

____ c. Did not get disoriented

Post evolution activities

____ a. Clean and sanitize facepiece

____ b. Refill cylinder

____ c. Replace cylinder in backpack properly

____ d. Perform operational check and put unit back in service

Evaluator _______________________________ Date ________________