Monoplace Delivery System

Monthly Hyperbaric Safety Notice: March 2006

Titanium Eyeglasses and Hyperbaric Medicine

Background

Some metals that are considered non-flammable under normal atmospheric conditions may become flammable in oxygen-enriched settings. Further, the amount of energy required to produce ignition is less in oxygen-enriched settings.

Titanium is one such metal. It is unique in that its fresh surface oxidizes instantly when exposed to oxygen. A stable, protective and strongly adherent oxide film is quickly formed. This process generates heat. If the amount of heat generated exceeds the rate in which it can be conducted away, ignition and burning may occur.

The Issue

There has been some discussion concerning the risk of titanium eyeglasses used by patients during hyperbaric oxygen therapy. Reference has been made to research that might support a recommendation to exclude titanium eyeglasses from hyperbaric chambers

The research cited is one that involved an environmental model well outside of the operating parameters of a hyperbaric treatment facility. When oxygen, at pressures ranging from 4.4 ATA to 6.1 ATA, was streamed across freshly exposed titanium, combustion resulted. Forceable fracture of fresh titanium at 6.1 ATA likewise caused combustion. The method of generation of fresh titanium, and the surface areas involved, greatly exceeded that which could be anticipated with the fracture of the titanium frame of a pair of eyeglasses.

In Columbia, we purposely attempted to fracture a set of titanium eyeglass frames. It took 7 attempts at twisting the frame 90 degrees, then returning it back 90 degrees, before the frame actually fractured.

At the present time there is no position taken by the National Fire Prevention Association on this issue of titanium as it relates to hyperbaric safety. It has been discussed within NFPA meetings, but a recommendation tabled pending additional and more definitive testing under circumstances more consistent with the environment we provide to our patients.

The ability to see clearly does much to maintain patient compliance and ensure the potential benefits of HBO therapy became available. The removal of eyeglasses may result in non-compliance and loss of access to otherwise life-saving, organ sparing, or limb-salvage therapy.

Bottom Line

At the present time it is not considered necessary to eliminate titanium eyeglasses from patients prior to entering the hyperbaric chamber. One can certainly ask each patient if their glasses are important to them during hyperbaric oxygen therapy. If not, then they may be removed and maintained outside the chamber. If the answer is yes, then the risk- benefit ratio is presently in favor of allowing their use.

Contributing Author: Dick Clarke, CHT

Dick Clarke Dick is President of National Baromedical Services, which he founded in 1986. His previous background included service in the British Royal Navy, diving instructor and underwater photographer, assistant director of the seabed habitat 'HydroLab' and several years in the offshore commercial diving industry. Dick heads the Baromedical Research Foundation where he serves as Principal Investigator for several international clinical trials. He is course director for 'Primary Training in Hyperbaric Medicine' and the 'HBO 2000' series of advanced hyperbaric symposia. Dick has been a NOAA Diving Medical Officer Training Course faculty member since 1983. He pioneered the Certification in Hyperbaric Technology (CHT) program, is a past president of the National Board of Diving and Hyperbaric Medical Technology and remains active at the committee level within the Undersea and Hyperbaric Medical Society.

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