Preventing explosions of hydrogen gas inhalers

Production and excretion of hydrogen (H(2)) gas in human was reported in 1969, since then it has been regarded as non-toxic molecule. For preventive and therapeutic medical uses, a possible treatment for cancer was reported and another article was published on how H(2) acts as a therapeutic antioxidant by selectively reducing cytotoxic oxygen radicals. A variety of H(2) gas inhalers have been available in the market for hospital and home uses. However, H(2) is odorless and flammable or explosive ignited by static electricity. We have examined the safety of a variety of H(2) gas concentrations from the viewpoint of flammability and explosion. We have also measured concentrations of H(2) gas inhalers in the market respectively. This paper also details how to control H(2) gas concentration for preventing explosions.