What is nitrous oxide (N2O)?
Commonly called "laughing gas," nitrous oxide was discovered in 1776 by Joseph Priestley. He inhaled the gas and noted that it caused confusion and analgesia. Later, in 1799, Humphrey Davy suggested its use in surgical operations. However for the next forty-five years nitrous oxide was used only for entertainment, in which respectable persons were shown to lose their usual demeanor, breaking into laughter, often accompanied by singing and dancing or aggressive behavior. Unwary persons were encouraged to volunteer for these exhibitions, particularly at fairgrounds. In 1844, Horace Wells, an American dentist, used the gas for tooth extraction, and two years later an American surgeon, William Morton, carried out major surgery under its influence. Nitrous oxide is not a very potent anesthetic; it was sometimes used at 100% for rapid induction of anesthesia, with subsequent addition of oxygen to avoid hypoxia.
How is nitrous oxide abused?
Since the earliest uses of nitrous oxide for medical or dental purposes, it has also been used recreationally, because it causes euphoria and slight hallucinations. Only a small number of recreational users (such as dental office workers or medical gas technicians) have legal access to pure nitrous oxide canisters that are intended for medical or dental use. Most recreational users obtain nitrous oxide from compressed gas containers which use nitrous oxide as a propellant for whipped cream or from automotive nitrous systems. Users typically inflate a balloon or plastic bag with nitrous oxide and inhale the gas for its effects.
Is nitrous oxide dangerous?
While nitrous oxide is not a dangerous substance per se, recreational users typically do not mix it with air or oxygen (as is standard procedure in a dentist's office) and thus may risk injury or death from lack of oxygen (anoxia). Nitrous oxide gas inhaled directly from a metal canister or tank, or through a connection to a homemade mask over a user's mouth, presents more potential danger due to two combined factors: its sedative effect which may leave a user overly relaxed; and such a system's automatic, continuous application which may prevent air (oxygen) from reaching the user, rendering them unconscious, and, after an extended period of time without oxygen, dead.
Is nitrous oxide addictive?
Nitrous oxide can be habit-forming because of its short-lived effect (generally from 1 - 5 minutes in recreational doses) and ease of access. Death can result if it is inhaled in such a way that not enough oxygen is breathed in. While the pure gas is generally not toxic, long-term use in very large quantities has been associated with vitamin B12 deficiency, anemia due to reduced hemopoiesis, neuropathy, tinnitus, and numbness in extremities. Harmful irreversible effects that may be caused by abuse of nitrous oxide include peripheral neuropathies and limb spasms. Pregnant women should not use nitrous oxide as chronic use is teratogenic and foetotoxic. One study in rats found that long term exposure to high doses of nitrous oxide may lead to Olney's lesions. Seizures, perception of time, and vision-altering perceptions are possible side effects.
How else is nitrous oxide used?
The gas is approved for use as a food additive (also known as E942), specifically as an aerosol spray propellant. Its most common uses in this context are in aerosol whipped cream canisters, cooking sprays, and as an inert gas used to displace bacteria-inducing oxygen when filling packages of potato chips and other similar snack foods.
Is nitrous oxide legal?
In the United States, possession of nitrous oxide is legal under federal law and is not subject to DEA purview. It is, however, regulated by the Food and Drug Administration under the Food Drug and Cosmetics Act; prosecution is possible under its "misbranding" clauses, prohibiting the sale or distribution of nitrous oxide for the purpose of human consumption. Many states have laws regulating the possession, sale, and distribution of nitrous oxide; but these are normally limited to either banning distribution to minors, or to setting an upper limit for the amount of nitrous oxide that may be sold without special license, rather than banning possession or distribution completely. In most jurisdictions, like at the federal level, sale or distribution for the purpose of human consumption is illegal. In the United Kingdom, recreational use of nitrous oxide is illegal, though sale and possession for non-inhalant use is legal for adults over the age of 18. According to Times online, and certain other sources, laughing gas is legal in the UK, and is sold in many night clubs around the country.