On September 11, 2001, the fire service saw first- hand the need for procedural and equipment interoperability for the emergency services. In the five years since that tragic day, we have made great strides in adopting operational procedures and firefighting equipment that integrate with local and federal resources.

Recently, the drive toward universal interoperability within the fire service has drawn SCBA cylinders into the fray. In fact, the current push for an interchangeable SCBA cylinder was brought to the National Fire Protection Association (NFPA) technical committee by the InterAgency Board for Equipment Standardization and InterOperability (IAB) as a need that is “overdue to the sustainment of field operations in contaminated atmospheres.”1 The proposed changes to NFPA 1981, Standard on Open-Circuit Self-Contained Breathing Apparatus for Fire and Emergency Services, if passed, would mandate an SCBA cylinder that would be interchangeable among the various brands of SCBA. (See “Interoperability vs. Interchangeability.”)

On the surface, the concept of cylinder interchangeability appears to be a no-brainer. During a large-scale incident, it may be necessary for multiple fire departments to work together. If these departments use different SCBA, they will be unable to share their cylinders in case of an air shortage.


One may question the necessity for creating a special interoperable cylinder. After all, doesn’t the Compressed Gas Association (CGA) fitting that is required on all cylinders provide a means for cylinders to be interoperable with all SCBA?

The answer is both yes and no. Under current federal regulations, the use of components (including cylinders) from one manufacturer’s SCBA to another manufacturer’s SCBA voids National Institute for Occupational Safety and Health (NIOSH) approvals. This rule applies even in cases where there is no discernable difference between cylinders.

This regulation holds true only to a point: OSHA regulations (which cover use) allow the use of other manufacturers’ cylinders on SCBA when deemed necessary to meet the tasks at hand.2 This exception is permitted even in cases where the cylinder-to-backpack connection is less than perfect.

While this appears to resolve the need for interchangeability, it is meant only as a stopgap measure in extreme situations and does nothing to address situations when there is a poor cylinder-to-backpack connection. The goal of the proposed cylinder interchangeability provision of NFPA 1981 is to make this situation permissible and seamless in any situation without voiding NIOSH approvals.


The concept of an interoperable or interchangeable SCBA cylinder is not new. The issues that have prevented it from being adopted are not new either. It has been discussed by the NFPA committee responsible for SCBA for years, but it did not make it out of committee until recently. In the past, the committee had resisted moving the proposal forward because of many unanswered questions and some negative implications of interoperability. Today, the proposal stands before you because of a sense of urgency surrounding the supposed need for interchangeability.

The Inability to Support Extensive SCBA Operations

Proponents argue that an interchangeable cylinder is necessary and beneficial for the fire service. They say that an interchangeable cylinder would result in streamlined fireground operations without interruptions in air supply.

Critics of the proposal claim that having adequate air for operations is not a problem. After all, operations in New York and Virginia on September 11, 2001, were not impacted by cylinder incompatibility problems.3 Historically speaking, they are correct. However, the need being considered is not a current one or even an ordinary operational need. Rather, today’s concern is that we will be underprepared for the extraordinary.

This is not the alarm of paranoid people but a response to today’s operational reality. The ability to sustain a large and long-term SCBA operation could conceivably be a real problem if (the experts say “when”) the emergency services are ever faced with such a challenge.

A concern has also been raised that cylinder refilling will be hampered if the ambient air in the area of a major incident is contaminated. The argument follows that the solution to this dilemma is to have clean air available in cylinders. The flaw with this justification is the assumption that we will somehow change cylinders in a contaminated atmosphere. If the air is not clean enough to put into the cylinders, should we really be changing our bottles and rehabbing in that area? It is not safe or realistic to expect that firefighters will change cylinders in a contaminated environment.

Cost Savings

Advocates suggest that if manufacturers’ cylinders were interchangeable, a free market would be created and prices would be driven down. In addition, departments would have the option of upgrading SCBA (or even switching SCBA manufacturers) without replacing the cylinders. They would be able to continue using their existing cylinders, thereby gaining the full value of the product life.

Having gone through the acquisition process just over a year ago, I know that there is already a very competitive market for SCBA systems. Although it is true that cylinder prices may be driven down, SCBA costs may rise because of their inherently higher research and development costs (today these costs are spread out across the SCBA and the cylinder).

Even if this argument turned out to be valid, it must be recognized that it is a double-edged sword. How many fire departments will be prevented from upgrading to the next generation of SCBA cylinder (be it smaller, lighter, greater capacity, and so on) because some bean counter in the finance office has decided that since the existing cylinders still have some life in them, they will do just fine? If an interchangeable cylinder were introduced to the fire service 15 years ago, how many of us would still be wearing steel bottles on our backs?


The consequences of adopting a “universal” or “interchangeable” SCBA cylinder are not so obvious. To fully understand what is being suggested and the potential ramifications of this change, a closer look is required.

Compatibility with Existing Equipment

Many people are wondering how the proposed interchangeable cylinder will integrate with existing cylinders and their SCBA. A common scenario many fire departments across North America have is the need to purchase new SCBA to add to their existing inventory (for instance, to replace damaged SCBA or put a new station or piece of apparatus in-service). The result would be having both new- and old-style cylinders in service at the same time.

In the case where a department is deploying with two different types of SCBA cylinders, two questions are immediately raised. The first is backward compatibility: Will the new cylinders be compatible with our existing SCBA? The second question has to do with forward compatibility: Will our existing cylinders be compatible with the new SCBA?

The simple answer to these questions is no. Only cylinders created after 2007 (that meet the proposed 2007 NFPA 1981 edition of the standard) would be interchangeable. In practical terms, this means that new cylinders can’t be used on existing SCBA and that existing cylinders can’t be used on new SCBA. In either case, the result is that a fire department is put in the position of incompatibility internally until all SCBA are replaced (a rather ironic situation considering the goal of the proposal). This incompatibility could last up to 15 years, the maximum life span of a carbon fiber SCBA cylinder.4

To avoid this scenario, the only options for a department are to upgrade or replace all existing SCBA. It is important to note that offering upgrade kits is an option for the manufacturer, not a requirement. If offered, upgrade to the new NFPA standard would be required to achieve compatibility. In many cases, this may require a new back frame, face piece, and cylinder valve. A pre-2002 SCBA would be even more costly to upgrade, since both the heads-up display and the Rapid Intervention Team Universal Air Connection will also have to be added. In all cases, NIOSH chemical, biological, radiological, and nuclear (CBRN) certification would be required. A manufacturer may decide that it would be too costly to offer its customers a complete upgrade to the 2007 NFPA standard.

Compatibility with Other New Cylinders

If the goal of this proposal is universal SCBA cylinder interoperability, then the proposal falls far short of the mark. The proposed change would result in the ability to interchange cylinders from various manufacturers, but cylinder interchangeability would be permitted only for cylinders within the same pressure and volume classification. (See “Pressure and Volume.”)

This is an important point for two reasons. First, five different pressure/volume classifications will be interchangeable only within their own pressure/volume family. Second, no cylinder pressure/volume combination is predominant in the fire service today. That means that true interoperability is never achievable with this proposed change.

Future Innovations

Another concern that has been raised about this proposal is the possible impact on product innovation. The argument follows that the proposed design specification may limit future (and in some cases existing) innovations that otherwise might have resulted in a better SCBA unit. In a sense, cylinder interchangeability will prevent future development from thinking too far outside the box.

Although there is some truth to this concern, the design jointly developed by various members of the NFPA committee (including manufacturers) does allow for some variation of cylinder design. That is because the cylinder must meet certain minimum and maximum dimensional and operational parameters. Within these parameters, variations are permissible. For example, if a manufacturer chose to add a distinctive feature to its cylinder, as long as the requirements are met (i.e., dimensions, CGA fitting and valve 180° apart, for example), the cylinder could still be certified as interchangeable.

However, any new innovations that do not fit into the proposed interchangeable cylinder parameters would be required to go through the NFPA standard change process; committees would decide what innovations to allow. Today, the market decides which new innovations should be incorporated into the SCBA.


If the goal is to have adequate air supplies for a major event, then it is clear that this is one case where interchangeability does not provide an adequate solution because of the compatibility problems stated above.

The need for interchangeability appears to be based on an assumption that fire departments are unprepared to sustain long-term field operations. Even in the extreme scenario, the problem is not that we will run out of cylinders (NFPA 1901 requires two for every SCBA) but rather refill capability. A more practical solution would be to address insufficient refilling capabilities where they exist.

There are several mobile air-supply solutions that are capable of rapidly filling SCBA cylinders. They could more easily and adequately resolve this possible need. This would be accomplished at lower cost to the fire service and without any of the potential compatibility problems of the proposed change.

RIT Universal Air Connection

It is important to note that the RIT universal air connection (UÅÇ) fitting, a requirement for NFPA-certified SCBA, should not be considered an alternative “fast-fill” option for an SCBA cylinder. It is not designed or intended for routine fill operations. Use of the RIT UAC for routine filling would be a violation of manufacturer guidelines and of the safe filling procedures outlined in NFPA 1500, Standard on Fire Department Occupational Safety and Health Program. More importantly, however, using the RIT UAC is considered a relatively dangerous practice that should not be done outside of a real emergency situation (i.e., a downed firefighter).


Some of the other changes being proposed for the 2007 edition of NFPA 1981 are enhanced voice communications and a requirement that all SCBA be NIOSH CBRN certified.

Enhanced Communications

Improving voice communications has been a reoccurring recommendation for the SCBA standard. It has improved gradually over the years; it now is being taken a step further to the point that electronic amplification likely would be necessary to meet the proposed standard. This change has broad support and, if passed, will improve communications while operating with SCBA.


The CBRN requirement is closely tied to the interchangeability requirement in that if we are to interchange cylinders, they all must have the highest level of protection available. To remove the CBRN requirement would create another obstacle for interchangeability.


The most serious shortcoming of the proposed NFPA 1981 is that it does not accomplish what it sets out to do. Proponents say cylinder interoperability is needed to address long-term incidents in contaminated atmospheres. However, interoperability fails to achieve its intended goal because of compatibility problems. At best, interoperability will be limited.

The proposed standard now stands before the fire service. Most of the technical questions have been answered or are answerable. The question before you is whether or not the proposed changes to the SCBA standard are necessary.

The argument has been made that the fire service needs cylinder interoperability to address prolonged operations in contaminated atmospheres. The question that remains is, Is the proposed solution the right answer to this potential need? Can we address this challenge in another, more appropriate way?

The issue is not about your department’s budget and who is going to pay for this change (an important piece of the puzzle, but not what should drive our safety decisions). What is at issue here is how this change could affect our ability to operate on the fireground and upgrade our equipment and that it likely would limit future innovations.

Furthermore, do the costs and consequences of this change justify the potential benefits? (Can you think of a better way for your department to spend its money than to upgrade your three-year-old SCBAs?) These questions and others should be given thoughtful consideration prior to making your comments.

Comments can be in support of or in opposition to the proposed changes. The proposed standard may be amended in part or in whole based on feedback received by the NFPA (see “Making a Comment.”) The period for comments on this proposal closes March 3, 2006. Whether this proposal is rejected or adopted depends on the feedback the NFPA Technical Committee receives. Please take the time to make your voice heard.

• • •

It is important to note that the costs, limitations, implications, and benefits discussed herein reflect the proposed standard as it is written now. Theoretically, there could be changes that fix some of the problems; no doubt, they, too, will bring their own set of questions, problems, and benefits.


1. InterAgency Board for Equipment Standardization and InterOperability Letter to NFPA Technical Committee, November 23, 2004.

2. OSHA Standard Interpretations, 06/20/1997: SCBA Cylinder Interchangeability.

3. Letters to NFPA Technical Committee for SCBA from Fairfax Co. Fire & Rescue and Fire Department of New York.

4. The Department of Transportation is considering extending the life limit of carbon-wrapped fiber cylinders to 25 years.

• • •


There is some confusion regarding the use of the terms interoperability and interchangeability. Both are being used to describe the proposed change. According to the Merriam-Webster Online Dictionary, interoperability refers to the ability of a system to use the parts or equipment of another system, and interchangeability is defined as “permitting mutual substitution.”

Although these two terms do not always mean the same thing, in the case of SCBA cylinders, both terms appear to be technically correct. The proposed cylinder would be interoperable with other SCBA and interchangeable with other cylinders.

However, a closer look reveals that only limited interoperability and interchangeability would be achieved because interchangeability/interoperability is achieved only within each pressure and volume classification.


Making A Comment

The proposed changes to NFPA 1981 [a.k.a. the Report on Proposals (ROP)] are currently subject to a 60-day comment period. Comments supporting or opposing the proposal should be made directly to the NFPA. The committee will review and act on all comments.

The committee will provide reasons for revising or rejecting any public comments it receives. They will be published in the Report on Comments (ROC), expected to be available in late August 2006.

More information about the NFPA document revision process is available at This Web site can be used to view the complete ROP and to make a comment on the proposal.

Comments can be submitted online or by mail or fax to the NFPA. The comment period closes on March 3, 2006, at 5 p.m. EST. For more information, or to request a copy of the ROP, call the NFPA at (800) 344-3555.

DAVID BERNZWEIG has been in the fire service for 16 years, the past nine with the Columbus (OH) Division of Fire, where he is a lieutenant/paramedic. He serves on the Columbus Firefighters Union Executive Board, is a member of the FEMA US&R Ohio Task Force One, and is a state fire and EMS instructor. He is a member of the NFPA Technical Committee on Respiratory Protection Equipment and has degrees in political science and economics from Ohio State University.

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