Hydrogen narcosis (also known as the hydrogen effect) is the

psychotropic A psychoactive drug, psychopharmaceutical, psychoactive agent or psychotropic drug is a chemical substance, that changes functions of the nervous system, and results in alterations in perception, mood, consciousness, cognition or behavior. Th ...

state induced by breathing

hydrogen Hydrogen is the chemical element with the symbol H and atomic number 1. Hydrogen is the lightest element. At standard conditions hydrogen is a gas of diatomic molecules having the formula . It is colorless, odorless, tasteless, non-toxic ...

at high pressures. Hydrogen narcosis produces symptoms such as hallucinations, disorientation, and confusion, which are similar to

hallucinogenic drugs Hallucinogens are a large, diverse class of psychoactive drugs that can produce altered states of consciousness characterized by major alterations in thought, mood, and perception as well as other changes. Most hallucinogens can be categorize ...

. It can be experienced by deep-sea divers who dive to below sea level breathing hydrogen mixtures. However, hydrogen has far less narcotic effect than nitrogen (which causes the better known

nitrogen narcosis Narcosis while diving (also known as nitrogen narcosis, inert gas narcosis, raptures of the deep, Martini effect) is a reversible alteration in consciousness that occurs while diving at depth. It is caused by the anesthetic effect of certain g ...

) and is very rarely used in diving. In tests of the effect of hydrogen narcosis, where divers dived to with a hydrogen–helium–oxygen (

hydreliox Hydreliox is an exotic breathing gas mixture of helium, oxygen and hydrogen. For the Hydra VIII (Hydra 8) mission at 50 atmospheres of ambient pressure, the mixture used was 49% hydrogen, 50.2% helium, and 0.8% oxygen. It is used primarily for r ...

) mixture containing 49% hydrogen, it was found that while the narcotic effect of hydrogen was detectable, the

neurological Neurology (from el, νεῦρον (neûron), "string, nerve" and the suffix -logia, "study of") is the branch of medicine dealing with the diagnosis and treatment of all categories of conditions and disease involving the brain, the spinal c ...

symptoms of

high-pressure nervous syndrome High-pressure nervous syndrome (HPNS – also known as high-pressure neurological syndrome) is a neurological and physiological diving disorder which can result when a diver descends below about using a breathing gas containing helium. The eff ...

were only moderate.

References

Underwater diving safety Breathing gases Diving medicine {{Underwater-diving-stub

See also

References