It is used primarily for research and scientific deep diving, usually below Script error: No such module "convert".. Below this depth, extended breathing of heliox gas mixtures may cause high pressure nervous syndrome (HPNS). Two gas mixtures exist that attempt to combat this problem: trimix and hydreliox. Like trimix, hydreliox contains helium and oxygen and a third gas to counteract HPNS. The third gas in trimix is nitrogen and the third gas in hydreliox is hydrogen. Because hydrogen is the lightest element, it is easier to breathe than nitrogen under high pressure.
Hydreliox has been tested to simulated depths in excess of Script error: No such module "convert". in a chamber by COMEX S.A., a French diving company. Although breathing hydreliox improves the symptoms seen in HPNS, tests have shown that hydrogen narcosis becomes a factor at depths of Script error: No such module "convert"..
- Fife, WP (1979). "The use of Non-Explosive mixtures of hydrogen and oxygen for diving". Texas A&M University Sea Grant. TAMU-SG-79-201.
- Rostain, JC; Gardette-Chauffour, MC; Lemaire, C; Naquet, R (1988). "Effects of a H2-He-O2 mixture on the HPNS up to 450 msw". Undersea Biomedical Research 15 (4): 257–70. ISSN 0093-5387. OCLC 2068005. PMID 3212843. Retrieved 2 March 2009.
- Hunger Jr, WL; Bennett, Peter B (1974). "The causes, mechanisms and prevention of the high pressure nervous syndrome". Undersea Biomedical Research 1 (1): 1–28. ISSN 0093-5387. OCLC 2068005. PMID 4619860. Retrieved 2008-06-24.
- Lafay, V; Barthelemy, P; Comet, B; Frances, Y; Jammes, Y (March 1995). "ECG changes during the experimental human dive HYDRA 10 (71 atm/7,200 kPa)". Undersea and Hyperbaric Medicine 22 (1): 51–60. PMID 7742710. Retrieved 2009-02-22.
- Abraini, JH; Gardette-Chauffour, MC; Martinez,, E; Rostain, JC; Lemaire, C (1994). "Psychophysiological reactions in humans during an open sea dive to 500 m with a hydrogen-helium-oxygen mixture". Journal of Applied Physiology (American Physiological Society) 76 (3): 1113–8. OCLC 8750-7587/94. PMID 8005852. Retrieved 1 March 2009.