2. Chamber Types: Which One Is Right?

Hyperbaric chambers are classified into four types, each suited to specific applications:

• Class A (Multiplace): Accommodates multiple patients, commonly pressurized with air, and delivers oxygen via masks or hoods. Ideal for complex cases requiring medical oversight but safer for wellness clinic use that 100% oxygen chambers.

• Class B (Monoplace): Treats one patient, most often (but not always) pressurized with 100% oxygen. Common in inpatient settings but riskier due to oxygen-rich environments where there may be a compromised airway.

• Class C (Veterinary): Designed for animals, not humans or human use and beyond the scope of this article.

• Class D (Soft Chambers): Portable, low-pressure chambers (up to 1.4 ATA), FDA-cleared for acute mountain sickness using compressed air.

Key Considerations: Hyperbaric medicine uses special chambers to deliver oxygen therapy, and the type of chamber depends on the treatment goal. Multiplace chambers (Class A), which hold multiple people, are safer for critically ill patients because they have attendants, monitoring equipment, and a lower fire risk. Multiplace chambers also afford customers the ability to be treated simultaneously and share in the comradery and increased cognitive function enjoyed by many. Older Monoplace chambers (Class B), designed for one person, are more slightly affordable but carry a higher fire risk in a 100% oxygen environment, as shown by past incidents. Find a newer, safer Monoplace option uses air pressure with oxygen delivered through a mask or hood, significantly reducing fire risk. Soft chambers (Class D) are gaining popularity but no build to standard exists for the American Society of Mechanical Engineers (ASME) standards.  Research published in the IHA journal (Therapeutic Sciences: Emerging Research in Medical Gases and Regenerative Biology) shows low-pressure hyperbarics (~1.5 ATA) can reduce inflammation and boost stem cell production more effectively than some of the higher pressures, with repeated studies confirming these results. However, conditions like decompression sickness or carbon monoxide poisoning, higher pressures (2.0–3.0 ATA) are still standard, as detailed in *The Art and Science of Hyperbaric Medicine* (Dituri & Sonners, 2024).

Oxygen Delivery: 100% Oxygen vs. Oxygen Concentrators: During the COVID-19 pandemic (2020–2022), oxygen concentrators became critical when medical-grade 100% oxygen prices surged due to reported shortages. Oxygen concentrators deliver approximately 95% oxygen, compared to 100% medical-grade oxygen used in traditional Monoplace chambers. There are no studies which compare the clinical efficacy difference between 100% and ~95% oxygen, but the slight difference in oxygen concentration is unlikely to significantly affect outcomes if the concentrator delivers adequate volume and pressure. At 2 ATA (equivalent to twice atmospheric pressure), an effective oxygen concentrator must provide sufficient flow to maintain oxygen concentration, typically through an oral-nasal mask (built in breathing system) or hood with inlet and outlet hoses. Devices using a single thin tube, nasal cannula, or unsealed non-rebreather mask are generally inadequate for hyperbaric use due to insufficient flow at depth.

For safety and efficacy, oxygen concentrators should meet medical-grade standards and be paired with chambers designed for air pressurization, such as Multiplace or newer Monoplace chambers. These systems reduce fire risk compared to 100% oxygen environments while maintaining therapeutic oxygen levels, aligning with NFPA 99 fire codes and FDA requirements.

3. Safety: How to Ensure a Chamber Is Safe?

Safety is non-negotiable in hyperbaric medicine, given the risks of rapid decompression, fire, and equipment failure. Simply put do not buy, get into or do business with chambers which are not built to contemporary professional standards and verified “stamped” and certified. This can be dangerous behavior for you, your clients or loved ones.

Safety Standards:

• FDA 510(k) Clearance: Mandatory for all clinical chambers. Uncertified chambers, often marketed for home use, have the possibility of failed components, such as low quality or defective seals, and improper ventilation or flow rate leading to catastrophic outcomes.

• ASME/PVHO-1: These codes ensure structural integrity, fire safety, and operational protocols and make assertions to build to specification for metal or acrylic chambers. ASME’s failure to establish standards for soft chambers has created a regulatory gap, exacerbating safety concerns and enabling market exploitation. Compliant chambers bear a “U-stamp” for verification.

• NFPA 99: The National Fire Protection Association a group who writes fire code which fire marshals use as an enforcement standard. This organization can invoke things like DOT standards even if the state does not. They require ASME and training for hyperbarics.

• Risk Mitigation: Using risk mitigation principles, facilities should conduct risk assessments to balance benefits (e.g., wound healing) against hazards (e.g., fire risk). Pressurizing with air and delivering oxygen via masks or hoods significantly reduces fire risk compared to 100% oxygen environments. Yet many manufacturers still make and distribute only those chambers which pressurize with 100% oxygen.

IHA Third-Party Verification: A Critical Safety Measure: The IHA’s third-party verification program is a cornerstone of hyperbaric facility safety, addressing the risks posed by non-compliant chambers and inadequate oversight. This rigorous process involves independent inspections by IHA-certified experts who evaluate chambers, operational protocols, and facility infrastructure against contemporary professional standards such as the ASME/PVHO-1, NFPA 99, and FDA standards. Verification includes:

• Chamber Integrity: Testing pressure vessels for structural soundness, ensuring compliance with ASME/PVHO-1 specifications (e.g., material strength, weld quality).

• Fire Safety Systems: Confirming the presence of fire suppression systems, oxygen storage systems and piping, oxygen monitoring, and adherence to NFPA 99 fire codes.

• Operational Protocols: Reviewing staff training records, operational procedures, emergency procedures, and maintenance logs to ensure readiness for incidents like fire, barotrauma or oxygen toxicity.

• Documentation: Verifying FDA 510(k) clearance and ASME data plates, rejecting non-compliant chambers.

• Common Sense: They verify a common-sense approach to chamber procedures which benefit the occupant and ensure that a clinic director is not putting profit over safety.

Verified facilities have a substantial reduction in safety incidents compared to non-verified facilities. Verification mitigates risks from unapproved chambers by identifying substandard equipment before it enters service. For example, IHA inspections have uncovered non-FDA cleared chambers with non-medical-grade fabrics prone to tearing and hard chambers with out-of-date acrylic portholes, preventing potential injuries. Clinics achieving IHA verification gain a safety certification, enhancing patient trust and regulatory compliance. The IHA underscores third-party verification as essential for protecting patients and legitimizing HBO facilities, particularly in non-clinical settings like wellness center. The IHA advocates verification for all hyperbaric facilities to close regulatory gaps and deter operators using unsafe equipment.

Dangers of Unapproved Chamber Use: The proliferation of non-FDA-cleared chambers poses a grave threat to patient safety and the hyperbaric industry. Unscrupulous manufacturers and operators shortcut the market by producing low-cost, non-compliant chambers, often imported from countries with minimal regulatory oversight. These devices bypass ASME/PVHO testing, using inferior materials like non-medical-grade fabrics, untested acrylics, or low-grade metals that fail under pressure. Operators and owners, enticed by costs 50–70% lower than compliant chambers, market these devices exploiting public demand driven by social media and celebrity endorsements. This practice not only endangers patients but also undermines legitimate HBO providers. The Troy, Michigan tragedy, linked to an oxygen-rich Monoplace chamber which was formally ASME built to but not maintained, exemplifies the catastrophic consequences of inadequate equipment and training. Without IHA third-party verification, these operators evade accountability, risking stricter regulations and public distrust that could derail the industry’s progress. The Art and Science of Hyperbaric Medicine warns that unchecked market shortcuts threaten HBO’s safety record, urging adoption of a knowledge-based approach for any off-label indication which is backed up with evidence-based practice. (Dituri & Sonners, 2024). To further drive this point, Medical Directors, Chamber Operators and Safety Directors have been charged with and found guilty of negligence and involuntary manslaughter for using unapproved, out of service or poorly maintained chambers on more than one occasion.

Innovation in Safety: Leading manufacturers are advancing safety with computer-controlled systems, touch-screen interfaces, and enhanced fire suppression. Multiplace chambers (2–4 seats) offer a return on investment within one year if used once daily, making them viable for clinics. The IHA advocates for chambers with minimally FDA 501K clearance for class D chambers and for class A and B chambers ASME/PVHO compliance and third-party verification to ensure reliability and safety.

The Future of Hyperbaric Medicine

The hyperbaric industry is expanding, with tens of thousands of treatments performed daily worldwide, many for off-label conditions like traumatic brain injury, post-concussion syndrome, and neurological disorders. However, resistance to change—termed the “hyperbarasaurus”—hinders progress. The IHA’s 2021 push for soft chamber standards highlights the need for regulatory evolution to address low-pressure devices, which have shown promise since the Gamow bag’s use for high-altitude cerebral edema. Bodies like the ASME must develop standards for soft chambers to balance innovation with safety, preventing exploitation by unqualified vendors.

Call to Action: To protect patients and the industry’s reputation, clinics must:

1. Employ IBUM’s ACCME-accredited training for all staff, including Safety Directors, Chamber Operators and Medical Directors.

2. Use only FDA-cleared, ASME/PVHO-compliant chambers, verified by IHA third-party inspections, and reject non-compliant soft or uncertified hard chambers.

3. Support IHA’s advocacy for regulatory updates to address soft chambers and off-label uses, backed by emerging research.

I opine all places offering oxygen are connected. This includes HBO in hospitals, clinics, mild HBO in clinics or homes, and even oxygen bars in shopping centers. They all provide oxygen therapy, and if something goes wrong in any of these places—like an accident or safety mistake—it can hurt the reputation of everyone working in this field. Hyperbaric medicine, when practiced safely, is a powerful tool for healing. These are inherently safe devices and given a 102-year accident review boasts less than 200 incidents and deaths worldwide given millions of treatments. However, this industry can do better. By prioritizing training, IHA third-party verification, and innovation, we can prevent tragedies like Troy, Michigan, and ensure HBO’s longevity as a trusted primary and adjunctive treatment modality.

References

• Dituri, J., Sonners, J. The Art and Science of Hyperbaric Medicine, NOW publishing 1st edition, 1-358 pages, Oct 2024, ISBN-13 979-8991597111