Rethinking Emergency Air Management: The Reilly Emergency Breathing Technique


When it comes to SCBA emergency air management, we have found that certain breathing methods are based on opinion and conjecture as opposed to testing and evaluation. The key to testing any method is to build in as many realistic controls as possible and to evaluate the subjects based on their individual performance. Articles and books teach breathing methods but may fail to stress the training and self-comparison necessary for a method to be effective for that firefighter. It’s common practice to take the stopwatch out in recruit class to time a firefighter to don his personal protective equipment (PPE), including SCBA, within 30 seconds, yet no time comparison is done with breathing techniques and use of SCBA.

We have all learned that a low-air alarm may not afford enough time to exit a structure and how to mark the point of no return. SCBA training has increased awareness and has educated firefighters to call for help as soon as they realize that they may be lost or running out of air. However, the fact still remains that firefighters will continue to find themselves faced with out-of-air emergencies. The National Fire Protection Association (NFPA) has tracked nonheart-related deaths inside structure fires since 1978, and smoke inhalation has been the number-one cause of death each year. This trend is continuing and underscores the need for a proven, reliable way to conserve air supply when your survival is at stake. It is important to remain calm and rely on training.


Routine is a word usually shadowed by complacency. Checking your SCBA at shift change is a routine that takes only a couple of minutes and should be as thorough as a parachute check. One aspect of the check is air pressure. How low does the bottle pressure have to be before topping off?

We evaluated 30-minute and 45-minute bottles with SCBA and found that every 100 psi in a 30-minute bottle translated to approximately eight to 10 breaths. Think about these figures next time you check your SCBA.


The reason we based our test on pressure and not volume is that firefighters make decisions based on their pressure gauge reading, level of exertion, environmental conditions, and experience. All manufacturers we researched base their SCBA low-air alarm and gauges on pressure, not volume. Only through practical training and evaluation can a firefighter make the best judgment call on how much survival time he may have left according to his pressure gauge.


The National Institute for Occupational Safety and Health (NIOSH) standard for determining the length of an air bottle is 40 liters of flow per minute. For you number crunchers, when filled to capacity,

  • A 30-minute bottle has an air volume of 1,274*
    @ 500 psi.
    1,274 liters ÷ 40 liters flow per minute = 31 minutes bottle time.
  • A 45-minute bottle has an air volume of 1,835 liters* @ 4,500 psi. 1,835 liters ÷ 40 liters flow per minute = 45 minutes bottle time.

* Volume may vary slightly among manufacturers.

However, practical experience will show a 30-minute bottle may last only 15 to 20 minutes. Listed below are a few reasons this may be the case.

• Actual air pressure is low to begin with

A bottle may be down a few hundred pounds to begin with. Air bottle gauges are commonly misinterpreted. SCBA or bottle pressure gauges are similar to fuel gauges in vehicles; readings could be off by 300 psi or more. Use common sense; if necessary, take the time to top off your bottle or switch it out when checking your SCBA.

• Poor mask seal

Annual fit testing is federally mandated and is absolutely necessary. However, fireground conditions have their own reality. Hastily donning your face piece can cost you valuable time later. Take a few seconds to get a good seal.

• Physical condition and experience

Poor physical condition and the lack of experience will also account for shorter bottle times.

• Breathing methods

There are various known air-management techniques, from Lamaze to yoga. Controlled breathing enhances the ability to be relaxed and stay focused. The popular fire service method, commonly known as skip breathing, was adopted from the scuba community (contrary to common belief, skip breathing is not recommended when diving). When skip breathing, breath is held intermittently during respirations. In theory, skip breathing was originally thought to extend air time. At best, skip breathing is a questionable method of breathing, and we found no documentation or scientific data to suggest otherwise. It is potentially hazardous to practice underwater and may actually decrease your survival time in an immediately dangerous to life or health atmosphere. There is no way of tricking the body when it comes to the balance between the levels of oxygen and carbon dioxide. The body’s automatic reflex is to keep these levels balanced. By holding breath, there is a buildup of carbon dioxide in the blood, increasing the heart rate and respirations. This was the consensus from the medical doctors we consulted, based on the physiological limitations of the human respiratory system. Therefore, you may think you have extended your air time; in reality, you may have shortened it. However, some individuals are comfortable with the skip breathing technique. Being relaxed is a key element when conserving air and, therefore, can result in extended air time.

Dr. David Cone, EMS division chief at Yale University, notes: “There are no studies demonstrating any benefit to skip breathing; and, yet, it is commonly taught throughout the country and found in firefighting textbooks.” Many departments in the Northeast stopped teaching skip breathing years ago without replacing it with any method. The medical directors we consulted would not approve any forms of skip breathing in their departments’ respiratory protection plans.


We have developed an alternative method of breathing called “Reilly-Emergency Breathing Technique” (R-EBT), which has been evaluated with positive results. In our evaluation, firefighters were tested in three ways: on an obstacle course, lying prone, and on treadmills. To ensure accurate results, we implemented the following controls:

Items Used for Each Firefighter Evaluated

Two identical air bottles were prepared at the same pressure using a digital air gauge (DAG). For time-conserving purposes, we used 600 psi as a target pressure when lying prone and walking on a treadmill.

Bottles were first filled to a few hundred pounds over target pressure, allowed to uniformly stabilize to the temperature of the room where the test was conducted, and then calibrated (bled) to target symmetrical bottle pressure.

Note: Temperature affects bottle air pressure, which can lead to an incorrect assumption of bottle air volume. That is why ample time must be allowed for bottles to stabilize to room temperature prior to calibration.

  • Full PPE (minus helmet)
  • Stopwatch
  • Heart Monitor

Digital Air Gauge

This was to ensure that air bottles were of identical air pressure to within 1 psi. The traditional needle gauge can vary by 100 psi. The DAG is accurate to within ± 1 psi.

Note: A cascade system or manifold cart cannot be used to equalize bottles. Residual pressure increases in the manifold after each bottle is closed, building pressure into the remaining bottles. Just the use of the DAG will result in a loss of 3 psi in bottle pressure with each use.


This will affect bottle pressure. It is critical that the bottles used for the evaluation stabilize to room temperature prior to calibration.


This was to ensure a consistent pace of the test subjects.

Heart Monitor

It was used for safety and to record the starting and ending pulse rates of test subjects.


1. Inhale as you normally would.

2. While exhaling, “hum” your breath out in a slow, consistent manner. The hum is low and usually cannot be heard over the low-air alarm. In situations where you need to disentangle your SCBA or rapidly move around obstacles, it may be difficult to continuously hum after each breath. Breathe as you normally would and intermittently use the R-EBT. The more you use the R-EBT, the more it will increase your survival time. Try it.

Have another person time your normal breath cycle (typically about four to six seconds). Then, have yourself timed using the technique (should be about 12 seconds, more or less). A low-air alarm activates between 1,000 and 1,250 psi, which we determined to be 50 to 80 breaths remaining in a 30-minute air bottle. Therefore, if you have an additional six seconds of time with each breath, it compounds to more air time remaining in your bottle.

For example: 50 breaths × 6 seconds = 300 seconds or approximately five minutes of additional time.


1. Take and record vitals of each test subject (pulse, blood pressure, and respiration).

2. Set the treadmill at 3 mph—zero incline. Keep it consistent for all test subjects. Have test subjects breathe as they normally would with SCBA. The individual firefighters tested were told to use any breathing technique they were aware of or comfortable with.

3. Have test subjects straddle the treadmill until they are ready to don the SCBA mask and start the clock; do this simultaneously.

4. Stop the clock when the test subject is completely out of air—mask sucked to face.

5. Record time and vitals of the test subject.

6. Break time until the test subject’s vitals return to the level at the beginning of the test (approximately 15 minutes).

7. Train the test subject on R-EBT during break time.

Note: Some individuals may be uncomfortable breathing in this manner at first. If this should happen, have them breathe normally for a few breaths then resume R-EBT.

8. Repeat test with the second bottle using R-EBT.

9. Record results.

To conserve test time during the treadmill evaluation, air bottles were calibrated and synchronized with a DAG to 500 to 600 psi as seen in photo 1. Twenty-two firefighters, from probies to seasoned veterans, were evaluated over a four-month period. Members of a hazmat squad, members of a scuba unit, and a marathon runner were in the group. Initial evaluations were conducted on an obstacle course, with full PPE, to create a physically demanding environment. Distance and time were recorded, with positive results.

(1) Using a digital air gauge. (Photo by Jeff Naples.)

We then progressed to the treadmill evaluation; again, firefighters were instructed to breathe as they normally would with donned SCBA; they had the option of using the technique of their choice. Vitals and time were monitored while on a treadmill at three miles per hour (mph) until their SCBA air ran out completely. Three miles per hour was chosen, not to reflect stressful working conditions but to allow for a safe, controlled pace and environment. The purpose was to demonstrate the firefighters’ originally chosen breathing techniques in direct comparison to R-EBT. All had an increased time when using R-EBT, with the overall improvement shown in percentage.

(2) Firefighters performing a treadmill test. (Photo by Brian Bonapace.)

Note: The SCBA low-air alarm will stop vibrating when bottle pressure is below 100-150 psi.

During a 15-minute rest (for vitals to return to normal), firefighters were instructed for the first time on R-EBT. After a “grueling” two-minute training session, firefighters repeated the test on the treadmill, this time with their newly learned skill. Twenty firefighters increased survival time. After a two-minute retraining, all 22 firefighters increased their survival time.

Tested firefighters had improved air times averaging more than 36 percent when using R-EBT (Figures 2-5).






At this time, we recommend R-EBT only for emergencies. You can use it in a structure fire if you are lost, trapped, or pinned or if your low-air alarm is sounding when you are exiting a building. If you forget to use the R-EBT and are in contact with the incident commander (IC), once your location is determined the IC can reassure you that help is on the way and instruct you to start using the R-EBT to conserve air. R-EBT is not limited to structure fires. It can be used for dive emergencies to conserve air as well as to extend air supply while advancing in a decontamination line. Our evaluation found that with only 600 psi remaining, the average firefighter can extend his air supply by approximately two minutes or more than 26 percent, compared with breathing methods used by firefighters during the initial phase of the evaluation.

It is important to ration your air supply when using SCBA, just as it is wise to ration anything in limited supply. Firefighters familiar with any effective breathing method in training will be better prepared in emergencies. R-EBT does not require extensive training. The training takes less than two minutes and can be added to SCBA confidence training. Recruits can practice any time their low-air alarm is activated and when exiting a structure. For veteran firefighters, the training can be added as a company drill in the annual OSHA-mandated SCBA training:

  • 1910.134(k)(1)(iii): “Employees must be trained to use the respirator effectively in emergency situations.”
  • 1910.134( c)(1)(iv): “Procedures for proper use of respirators in routine and reasonably foreseeable emergency situations.”

NFPA 1404, Standard for Fire Service Respiratory Protection Training, (2006 ed.) and NFPA 1500, Standard on Fire Department Occupational Safety and Health Program (2007 ed.), are two consensus standards to refer to in your department’s respiratory protection plan.

(3) Even when following NFPA 1404, the inherent risks of this job demand that we are trained in emergency breathing techniques and last-chance filter technology. (Photo courtesy of authors.)

R-EBT is just another tool in the toolbox and does not take the place of activating your PASS alarm after radioing your position. This should take place as soon as you realize you may be in trouble. Minutes can be the difference between rescue or recovery. It seems that in the many advancements of safety, there is added expense, weight, and longer training classes. The R-EBT costs nothing to implement, weighs nothing, and can be seamlessly added to your department’s existing SCBA training program. The Middlesex Fire Academy in Connecticut has added this technique to the curriculum of several Firefighter 1 programs. R-EBT has also been taught to experienced firefighters in the Tactical Considerations of Search class and to firefighters from Connecticut, New Jersey, Rhode Island, and New York.

We encourage departments to put this method as well as any other method being taught through comparison testing. Because of the many variables associated with air management, comparison testing must start with each firefighter to determine the best method for that individual. Understanding personal air management limitations is critical to every firefighter. There is no magic bullet when it comes to a breathing technique. What is important is that we establish a standard method for evaluating personal air management. Our method of evaluation is only a start. Today’s technical advancements enable us to be more measured and precise when it comes to air management. Similar to the significance a pound of tire pressure can have at a NASCAR race, those extra seconds of air time can add up.

For additional information or to share the results of your own test, go to

Thanks to the following for their assistance with this article: Dave Berardesca, chief, Hamden (CT) Fire Department; Brian Bonapace, New Haven (CT) Fire Department; Dr. David Cone, EMS division chief, New Haven Hospital at Yale; Jim Duffy, shift commander, Wallingford (CT) Fire; Parker Gallo, University of New Haven, Connecticut; Rich Hiedgerd, chief of operations, Wallingford (CT) Fire Department; Mike McLaughlin, Ridgewood (NJ) Fire Department; Jeff Naples, Hamden (CT) Fire Department; and Jay Woron, director of training, Middlesex County (CT) Fire Academy.

KEVIN J. REILLY is a member of the Ridgewood (NJ) Fire Department. He is an FDIC H.O.T. instructor and a member of the board of directors of the Fire Safety Directors Association of New York City and the Cyanide Poisoning Treatment Coalition. He writes emergency action plans and is a high-rise/life safety consultant in New York City. He is a contributing author to Carbon Monoxide Poisoning, edited by Dr. David Penney (October 2007); the creator of the Reilly-Emergency Breathing Technique; the founder of FSP Instruments, Inc.; and a co-founder of His article “Chronic CO Poisoning in Firefighters” was published in Fire Engineering in June 2006.

FRANK RICCI is the director of fire services for ConnectiCOSH. He is an adjunct instructor for the New Haven Fire Department, Emergency Training Solutions, and Middlesex County Fire School and a H.O.T. instructor and lecturer for FDIC. He has been a subject matter consultant for Yale, FDNY, and various manufacturers. He is a contributing author to Carbon Monoxide Poisoning (CRC Press, 2008). Ricci has worked on a heavy rescue unit covering Bethesda and Chevy Chase, Maryland, and was a “student live-in” at station 31 in Rockville, Maryland. He was a co-author of the Connecticut whistle blower law. He most recently developed for Fire Engineering the Smoke Showing film. His DVD Firefighter Survival Techniques/Prevention to Intervention will be available at FDIC.

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