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A Closer Look at Hyperbaric Safety and Training

This author describes the risk posed by the increasing numbers of hyperbaric oxygen therapy (HBOT) facilities operating with inadequate training and little or no oversight.

For the most part, those of us who operate hyperbaric medicine programs in the organized health care environment do so with a high degree of safety and training.

We use hyperbaric chambers that have been designed, fabricated, installed, and operated in accordance to recognized codes and standards. Physicians are credentialed by their respective hospitals to practice hyperbaric medicine while nurses and technical personnel have obtained the necessary training to give them the skills to perform their service to the patients they treat. Additionally, each facility has a dedicated safety director whose responsibilities are defined by code and who are the focal point of organizing and conducting routine safety drills.

However, when one ventures outside of that “safety net,” so to speak, it all falls apart.

The number of free-standing or non-affiliated hyperbaric facilities in this country is rapidly growing. This is especially true with regard to the use of low-pressure, portable fabric hyperbaric chambers (commonly referred to as soft sided or “mild” chambers). Their use is rapidly spreading in chiropractors’ offices, health spas/wellness centers, and the home. All of these have little or no oversight, and those in the spa/wellness environment and homes generally operate with no training or professional medical involvement.

Hyperbaric chambers in these settings are typically designed for an internal operating pressure of 3–5 psi and are intended to be pressurized with air. The Food and Drug Administration (FDA) has cleared them for only one indication: acute mountain sickness.1 Further, the FDA prohibits the use of “enriched air” in any manner with these devices.2 You might wonder, what is “enriched air”? While there is no formal FDA definition, the FDA’s intent is that any breathing gas mixture with an oxygen concentration of greater than 21% is considered to be “enriched.” Virtually every one of these chambers is used in conjunction with oxygen concentrators, which results in an elevated oxygen concentration inside the chamber beyond 21%.

I am aware of one facility that actually pressurizes its chambers with 100% oxygen supplied from high-pressure cylinders. This practice creates an extreme fire risk to the chamber occupant.

If one were to conduct a search on the internet on hyperbaric chambers, there would be a number of links to various sites that are promoting the use of these low-pressure devices. If you were to look at the indications they are promoting for the use of these devices you will be amazed at how extensive their “benefits” list is. Certainly, the list goes well beyond acute mountain sickness. To address this concern, the FDA issued a consumer warning in August 2013 cautioning against low-pressure device use for off-label indications.3 The FDA has also issued a total of eight warning letters to manufacturers and distributors of these chambers. Citations noted in these letters ranged from promoting these chambers’ use with oxygen concentrations to a lack of quality control systems in place for their manufacture. Unfortunately, most people who purchase and use these chambers have no idea that these warnings have been issued.

The FDA has also labeled these chambers as “prescriptive” devices, meaning they cannot be sold or used in the absence of a prescription from a licensed practitioner. It is common practice not to require a prescription in free-standing hyperbaric centers that use these chambers. For example, there are two spas in the city I live in that use these chambers and do not require a prescription.

The argument that I frequently hear is that the FDA does not regulate the practice of alternative medicine and this facility is using the chambers in support of alternative medicine. Well, we all know that the FDA does not regulate the practice of medicine, alternative or otherwise. However, the FDA does regulate the use of medical devices and these chamber fall under the prescriptive mandate.

What the ASME and NFPA Standards Require

There are a number of concerns that go well beyond compliance to FDA rules and regulations. First, and most importantly, none of these chambers comply with the engineering requirements defined by organizations like the American Society of Mechanical Engineers (ASME) and the National Fire Protection Association (NFPA).

Let’s discuss the ASME first. In 1971, the ASME created a focused technical committee to develop standards that apply to hyperbaric chambers intended for human occupancy. The ASME Technical Committee on Pressure Vessels for Human Occupancy published its first code in 1977 (ASME PVHO-1), which has since been updated.4 While there is much that can be said about this code, the bottom line is that none of these low-pressure chambers meet this code.

Second is the NFPA. The first NFPA fire safety standard for hyperbaric facilities was published in 1967. In 1984, it was integrated into NFPA 99: the Health Care Facilities Code, which devotes an entire chapter to hyperbaric facilities.5 Since 1967, the NFPA has mandated that any hyperbaric chamber used for treatment be compliant with ASME PVHO-1. Therefore, these chambers meet neither the ASME PVHO code nor NFPA 99.

Beginning with the 2000 edition of the Life Safety Code (NFPA 101), hyperbaric chambers that are not located in a structure that falls under NFPA 99 but does fall under NFPA 101 (a business occupancy, for example) must comply with the requirements identified in NFPA 99.6 It is important to know that while neither ASME PVHO-1 nor NFPA 99 is mandated in all 50 states, NFPA 101 is. Therefore, by reference, compliance to ASME PVHO and NFPA is a national mandate.

Why Are So Many Hyperbaric Chambers Non-Compliant?

If the above is in effect a national requirement, then how it is that there are so many of these code-noncompliant chambers in use? The reason is a lack of regulatory oversight and awareness. There is a hierarchy of authorities having jurisdiction (AHJ), which is an office that has the authority to close you down. AHJs include federal, state, county and local governmental agencies. The most practical AHJ in our world is the local fire marshal. Unfortunately, the local fire marshal has no way of knowing that these devices are being used in his/her jurisdiction.

When a traditional hyperbaric chamber is being installed in a given facility, the chamber must be piped (plumbed) for oxygen and chamber exhaust. The piping is performed under an approved permit issued by the fire prevention office. Application for permit informs the AHJ that a hyperbaric chamber is being installed in his/her jurisdiction and that a certificate of occupancy must be issued before the facility begins to treat patients.

These portable chambers are just that—portable. They are typically delivered in several boxes by a shipping agent such as FedEx or UPS and can be unboxed and assembled in less than an hour. There is no need for piping (even though the code requires it). So, the local AHJ does not even know that these chambers are in the jurisdiction.

Allow me to return to the issue of training. In the organized health care world, we recognize that the minimum training for someone to provide HBOT is an approved introductory course of at least 40-hours of instruction. The purveyors of these low-pressure chambers claim that they are so simple to use that little or no training is required. Therefore, the vast majority of users are lay people with no medical background whatsoever and no knowledge of the complications possible from a hyperbaric chamber exposure.

The degree of ignorance on hyperbaric chamber safety issues is staggering. For example, a search on Google shows that patients (“clients” is probably a better word) are encouraged to take various electrical devices into the chamber with them for entertainment. Devices like tablets, cell phones etc., are routinely allowed in the chamber during “treatment.” Given the fact that most are being used with oxygen concentrators with internal oxygen concentration certainly above 23.5% (the level above which electrical grounding is required by code), this practice greatly increases the risk of fire in the chamber.


I can go on, but hopefully you now have a better understanding of this growing concern. Lay people using chambers that do not meet code in any way and are providing a treatment modality for off-label indications with little or medical training. It’s worrisome at best.

With that in mind, what can you do? Well, at the very least, you can know your community. I think it is safe to say there are businesses using these hyperbaric devices in virtually every large city—perhaps yours. Also, educate when possible. Network with your local AHJ and first responders that would be called to your location should there be a need to do so. Mostly likely, they have no clue what you do and the more knowledge they have about your unique requirements, the better.

W.T. Workman, BS, MS, CAsP, CHT-A, FAsMA, FUHM is the former Director of Quality Assurance and Regulatory Affairs for the Undersea and Hyperbaric Medical Society.


W.T. Workman, BS, MS, CAsP, CHT-A, FAsMA, FUHM

1. Undersea and Hyperbaric Medical Society. UHMS position statement: low-pressure fabric hyperbaric chambers. . Revised July 10, 2018.
2. 510(k) Clearances. FDA. 2018. .
3. U.S. Food and Drug Administration. Hyperbaric oxygen therapy: Don’t be misled. . August 23, 2013.
4. American Society of Mechanical Engineers. Safety Standard for Pressure Vessels for Human Occupancy. PVHO-1-2019. .
5. National Fire Protection Association. NFPA 99: the Health Care Facilities Code. .
6. National Fire Protection Association. NFPA 101: Life Safety Code. .

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