Inhalant

Inhalants are a broad range of household and industrial chemicals whose volatile vapors or pressurized gases can be concentrated and breathed in via the nose or mouth to produce intoxication, in a manner not intended by the manufacturer. They are inhaled at room temperature through volatilization (in the case of gasoline or acetone) or from a pressurized container (e.g., nitrous oxide or butane), and do not include drugs that are sniffed after burning or heating.

While a few inhalants are prescribed by medical professionals and used for medical purposes, as in the case of inhaled anesthetics and nitrous oxide (an anxiolytic and pain relief agent prescribed by dentists), this article focuses on inhalant use of household and industrial propellants, glues, fuels, and other products in a manner not intended by the manufacturer, to produce intoxication or other psychoactive effects. These products are used as recreational drugs for their intoxicating effect. According to a 1995 report by the National Institute on Drug Abuse, the most serious inhalant use occurs among homeless children and teenagers who "live on the streets completely without family ties." Inhalants are the only substance used more by younger teenagers than by older teenagers. Inhalant users inhale vapor or aerosol propellant gases using plastic bags held over the mouth or by breathing from a solvent-soaked rag or an open container. The practices are known colloquially as "sniffing", "huffing" or "bagging".

The effects of inhalants range from an alcohol-like intoxication and intense euphoria to vivid hallucinations, depending on the substance and the dose. Some inhalant users are injured due to the harmful effects of the solvents or gases or due to other chemicals used in the products that they are inhaling. As with any recreational drug, users can be injured due to dangerous behavior while they are intoxicated, such as driving under the influence. In some cases, users have died from hypoxia (lack of oxygen), pneumonia, heart failure, cardiac arrest, or aspiration of vomit. Brain damage is typically seen with chronic long-term use of solvents as opposed to short-term exposure.

While legal when used as intended, in England, Scotland, and Wales it is illegal to sell inhalants to persons likely to use them as an intoxicant. As of 2017, thirty-seven US states impose criminal penalties on some combination of sale, possession or recreational use of various inhalants. In 15 of these states, such laws apply only to persons under the age of 18.

Categories

Medical inhalants

A small number of recreational inhalant drugs are pharmaceutical products that are used illicitly.

* Antidote to cyanide poisoning
** Alkyl nitrites (poppers)
* Inhalational anesthetics used as general anesthetics
** Nitrous oxide
** Xenon
* Historical general anesthetics
** Chloroethane
** Chloroform
** Ether

Medical anesthetics that have been used as recreational drugs include diethyl ether (no longer used medically due to high flammability and development of safer alternatives) and nitrous oxide, widely used since the late 20th century by dentists as an anti-anxiety drug and mild anesthetic during dental procedures. The effects of ether intoxication are similar to those of alcohol intoxication, but more potent. Also, due to NMDA antagonism, the user may experience all the psychedelic effects present in classical dissociatives such as ketamine in the forms of thought loops and the feeling of the mind being disconnected from one's body. Nitrous oxide is a dental anesthetic that is used as a recreational drug, either by users who have access to medical-grade gas canisters (e.g., dental hygienists or dentists) or by using the gas contained in whipped cream aerosol containers. Nitrous oxide inhalation can cause pain relief, depersonalization, derealization, dizziness, euphoria, and some sound distortion.

Recreational use

Liquids

=Alkyl nitrites

=

Ingestion of alkyl nitrites can cause methemoglobinemia, and by inhalation it has not been ruled out.

The sale of alkyl nitrite-based poppers was banned in Canada in 2013. Although not considered a narcotic and not illegal to possess or use, they are considered a drug. Sales that are not authorized can now be punished with fines and prison. Since 2007, reformulated poppers containing isopropyl nitrite are sold in Europe because only isobutyl nitrite is prohibited. In France, the sale of products containing butyl nitrite, pentyl nitrite, or isomers thereof, has been prohibited since 1990 on grounds of danger to consumers. In 2007, the government extended this prohibition to all alkyl nitrites that were not authorized for sale as drugs. After litigation by sex shop owners, this extension was quashed by the Council of State on the grounds that the government had failed to justify such a blanket prohibition: according to the court, the risks cited, concerning rare accidents often following abnormal usage, rather justified compulsory warnings on the packaging.

In the United Kingdom, poppers are widely available and frequently (legally) sold in gay clubs/bars, sex shops, drug paraphernalia head shops, over the Internet and on markets. It is illegal under Medicines Act 1968 to sell them advertised for human consumption, and to bypass this, they are usually sold as odorizers. In the U.S., originally marketed as a prescription drug in 1937, amyl nitrite remained so until 1960, when the Food and Drug Administration removed the prescription requirement due to its safety record. This requirement was reinstated in 1969, after observation of an increase in recreational use. Other alkyl nitrites were outlawed in the U.S. by Congress through the Anti-Drug Abuse Act of 1988. The law includes an exception for commercial purposes. The term ''commercial purpose'' is defined to mean any use other than for the production of consumer products containing volatile alkyl nitrites meant for inhaling or otherwise introducing volatile alkyl nitrites into the human body for euphoric or physical effects. The law came into effect in 1990. Visits to retail outlets selling these products reveal that some manufacturers have since reformulated their products to abide by the regulations, through the use of the legal cyclohexyl nitrite as the primary ingredient in their products, which are sold as video head cleaners, polish removers, or room odorants.

Gases

=Nitrous oxide

=

Nitrous oxide can be categorized as a dissociative drug, as it can cause visual and auditory hallucinations. Anesthetic gases used for surgery, such as nitrous oxide or enflurane, are believed to induce anesthesia primarily by acting as NMDA receptor antagonists, open-channel blockers that bind to the inside of the calcium channels on the outer surface of the neuron, and provide high levels of NMDA receptor blockade for a short period of time.

This makes inhaled anesthetic gases different from other NMDA antagonists, such as ketamine, which bind to a regulatory site on the NMDA-sensitive calcium transporter complex and provide slightly lower levels of NMDA blockade, but for a longer and much more predictable duration. This makes a deeper level of anesthesia achievable more easily using anesthetic gases but can also make them more dangerous than other drugs used for this purpose.
Nitrous oxide is thought to be particularly non-toxic, though heavy long-term use can lead to a variety of serious health problems linked to the destruction of vitamin B12 and folic acid.

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 as a recreational drug. Many states have laws regulating the possession, sale, and distribution of nitrous oxide. Such laws usually ban distribution to minors or limit the amount of nitrous oxide that may be sold without a special license. For example, in the state of California, possession for recreational use is prohibited and qualifies as a misdemeanor. In New Zealand, the Ministry of Health has warned that nitrous oxide is a prescription medicine, and its sale or possession without a prescription is an offense under the Medicines Act. This statement would seemingly prohibit all non-medicinal uses of the chemical, though it is implied that only recreational use will be legally targeted. In India, for general anesthesia purposes, nitrous oxide is available as Nitrous Oxide IP. India's gas cylinder rules (1985) prohibit the transfer of gas from one cylinder to another for breathing purposes. Because India's Food & Drug Authority (FDA-India) rules state that transferring a drug from one container to another (refilling) is equivalent to manufacturing, anyone found doing so must possess a drug manufacturing license.

Safety

In contrast, a few inhalants like amyl nitrite and diethyl ether have medical applications and are not toxic in the same sense as solvents, though they can still be dangerous when used recreationally.

Non-medical inhalants

Ethanol (the alcohol which is normally drunk) is sometimes inhaled.

The ethanol must be converted from liquid into gaseous state (vapor) or aerosol (mist), in some cases using a nebulizer, a machine that agitates the liquid into an aerosol. The sale of nebulizers for inhaling ethanol was banned in some US states due to safety concerns.

Toxic inhalants

Most inhalant drugs that are used non-medically are ingredients in household or industrial chemical products that are not intended to be concentrated and inhaled.

* Hydrocarbon poisoning
** Gases
*** Butane
*** Propane
** Solvents
*** Gasoline/petrol
*** Toluene
** Liquid/gas mixtures
*** Freon
* Ketones
** Solvents
*** Acetone

Solvents

A wide range of volatile solvents intended for household or industrial use are inhaled as recreational drugs. This includes petroleum products (gasoline and kerosene), toluene (used in paint thinner, permanent markers, contact cement and model glue), and acetone (used in nail polish remover). These solvents vaporize at room temperature.

Until the early 1990s, the most common solvents that were used for the ink in permanent markers were toluene and xylene. These two substances are both harmful and characterized by a very strong smell. Today, the ink is usually made on the basis of alcohols (e.g. 1-Propanol, 1-butanol, diacetone alcohol and cresols).

Organochlorine solvents are particularly hazardous; many of these are now restricted in developed countries due to their environmental impact.

Legality

Even though solvent glue is normally a legal product, there is a 1983 case where a court ruled that supplying glue to children is illegal. ''Khaliq v HM Advocate'' was a Scottish criminal case decided by the High Court of Justiciary on appeal, in which it was decided that it was an offense at common law to supply glue-sniffing materials that were otherwise legal in the knowledge that they would be used recreationally by children. Two shopkeepers in Glasgow were arrested and charged for supplying children with "glue-sniffing kits" consisting of a quantity of petroleum-based glue in a plastic bag. They argued there was nothing illegal about the items that they had supplied. On appeal, the High Court took the view that, even though glue and plastic bags might be perfectly legal, everyday items, the two shopkeepers knew perfectly well that the children were going to use the articles as inhalants and the charge on the indictment should stand. When the case came to trial at Glasgow High Court the two were sentenced to three years' imprisonment.

As of 2023, in England, Scotland, and Wales it is illegal to sell inhalants, including solvent glues, to persons of any age likely to use them as an intoxicant. As of 2017, thirty-seven US states impose criminal penalties on some combination of sale, possession or recreational use of various inhalants. In 15 of these states, such laws apply only to persons under the age of 18.

Gasoline

Gasoline sniffing can cause lead poisoning, in locations where leaded gas is not banned.

Toluene

Toluene can damage myelin.

Gases

A number of gases intended for household or industrial use are inhaled as recreational drugs. This includes chlorofluorocarbons used in aerosols and propellants (e.g., aerosol hair spray, aerosol deodorant). A gas used as a propellant in whipped cream aerosol containers, nitrous oxide, is used as a recreational drug. Pressurized canisters of propane and butane gas, both of which are intended for use as fuels, are used as inhalants.

Legality

"New Jersey... prohibits selling or offering to sell minors products containing chlorofluorocarbon that is used in refrigerant."

Dangers

Statistics on deaths caused by heavy inhalant use are difficult to determine. It may be severely under-reported because death is often attributed to a discrete event such as a stroke or a heart attack, even if the event happened because of inhalant use. Inhalant use was mentioned on 144 death certificates in Texas during the period 1988–1998 and was reported in 39 deaths in Virginia between 1987 and 1996 from acute voluntary exposure to used inhalants.

Chronic solvent-induced encephalopathy

Chronic solvent-induced encephalopathy (CSE) is a condition induced by long-term exposure to organic solvents, often—but not always—in the workplace, that lead to a wide variety of persisting sensorimotor polyneuropathies and neurobehavioral deficits even after solvent exposure has been removed.

Sudden sniffing death syndrome

Sudden sniffing death syndrome, first described by Millard Bass in 1970, is commonly known as SSDS.

Solvents have many potential risks in common, including pneumonia, cardiac failure or arrest, and aspiration of vomit. The inhaling of some solvents can cause hearing loss, limb spasms, and damage to the central nervous system and brain. Serious but potentially reversible effects include liver and kidney damage and blood-oxygen depletion. Death from inhalants is generally caused by a very high concentration of fumes. Deliberately inhaling solvents from an attached paper or plastic bag or in a closed area greatly increases the chances of suffocation. Brain damage is typically seen with chronic long-term use as opposed to short-term exposure. Parkinsonism (see: Signs and symptoms of Parkinson's disease) has been associated with huffing.

Female inhalant users who are pregnant may have adverse effects on the fetus, and the baby may be smaller when it is born and may need additional health care (similar to those seen with alcohol – fetal alcohol syndrome). There is some evidence of birth defects and disabilities in babies born to women who sniffed solvents such as gasoline.

In the short term, death from solvent use occurs most commonly from aspiration of vomit while unconscious or from a combination of respiratory depression and hypoxia.

Inhaling butane gas can cause drowsiness, unconsciousness, asphyxia, and cardiac arrhythmia. Butane is the most commonly misused volatile solvent in the UK and caused 52% of solvent-related deaths in 2000. When butane is sprayed directly into the throat, the jet of fluid can cool rapidly to −20 °C by adiabatic expansion, causing prolonged laryngospasm.

Some inhalants can also indirectly cause sudden death by cardiac arrest, in a syndrome known as "sudden sniffing death". The anaesthetic gases present in the inhalants appear to sensitize the user to adrenaline and, in this state, a sudden surge of adrenaline (e.g., from a frightening hallucination or run-in with aggressors), may cause fatal cardiac arrhythmia.

Furthermore, the inhalation of any gas that is capable of displacing oxygen in the lungs (especially gases heavier than oxygen) carries the risk of hypoxia as a result of the very mechanism by which breathing is triggered. Since reflexive breathing is prompted by elevated carbon dioxide levels (rather than diminished blood oxygen levels), breathing a concentrated, relatively inert gas (such as computer-duster tetrafluoroethane