First post here guys. Very quick background which brings me to the question i have. My trade background is in the automotive industry as a mechanic, mines as a drill fitter, hobbies include flying, cars and scuba diving. Just recently i have changed career paths again, and will be working with my Dad in bringing Hyperbaric Chambers into Australia from the States. This design has been around for 20 years, and we are in the process of getting these TGA (therapeutic goods administration of Australia) approved, similar to FDA in the USA. One question i haven't been able to get a decent answer for is in regards to oxygen toxicity. Having done a bit of diving, that was a big part in the max bottom depth of an advanced recreational diver, being 1.6ata's, around 50psi in old terms, anything after that and the extra pressure can cause hyperoxia, breathing roughly 160% oxygen levels, which can lead to seizures, and potential drowning from regulator loss and so on. Now when it comes to Hyperbaric Chambers, which are used for medical treatments, oxygen toxicity is unheard of. Dad has done over 1000 (dives) treatments on patients with never an issue, these treatments last 90min and are at 2.6 atmospheres. I'm aware that the safety risks of a convulsion whilst in a chamber will not have the same risks, i dont have a definitive answer to that question. It was only recently a few divers i met recently asked me about oxygen toxicity, and i said id get back to them. I'm sure i'll be asking a few more questions in the future, i love learning about things that interest me, and it helps knowing what you're fixing, even its its the science behind it.