inhalants. general risks regardless of which inhalant is used, inhaling vapors or gases can lead to injury or death. one major risk is hypoxia (lack of oxygen), which can occur due to inhaling fumes from a plastic bag, or from using proper inhalation mask equipment (e.g., a medical mask for nitrous oxide) but not adding oxygen or room air. another danger is freezing the throat. when a gas that was stored under high pressure is released, it cools abruptly and can cause frostbite if it is inhaled directly from the container. this can occur, for example, with inhaling nitrous oxide. when nitrous oxide is used as an automotive power adder, its cooling effect is used to make the fuel-air charge denser. in a person, this effect is potentially lethal. many inhalants are volatile organic chemicals and can catch fire or explode, especially when combined with smoking. as with many other drugs, users may also injure themselves due to loss of coordination or impaired judgment, especially if they attempt to operate machinery. 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. the middle container is cooking spray, a household product, which is used as an inhalant. 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, the second cause being especially a risk with heavier-than-air vapors such as butane or gasoline vapor. deaths typically occur from complications related to excessive sedation and vomiting. actual overdose from the drug does occur, however, and inhaled solvent use is statistically more likely to result in life-threatening respiratory depression than intravenous use of opioids such as heroin. most deaths from solvent use could be prevented if individuals were resuscitated quickly when they stopped breathing and their airways cleared if they vomited. however, most inhalant use takes place when people inhale solvents by themselves or in groups of people who are intoxicated. certain solvents are more hazardous than others, such as gasoline. in contrast, a few inhalants like amyl nitrate 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. 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. risks of specific agents the hypoxic effect of inhalants can cause damage to many organ systems (particularly the brain, which has a very low tolerance for oxygen deprivation), but there can also be additional toxicity resulting from either the physical properties of the compound itself or additional ingredients present in a product. organochlorine solvents are particularly hazardous; many of these are now restricted in developed countries due to their environmental impact. methylene chloride, after being metabolized, can cause carbon monoxide poisoning. gasoline sniffing can cause lead poisoning, in locations where leaded gas is not banned. ingestion of alkyl nitrites can cause methemoglobinemia, and by inhalation it has not been ruled out. carbon tetrachloride can cause significant damage to multiple systems, but its association with liver damage is so strong that it is used in animal models to induce liver injury. use of butane, propane, nitrous oxide and other inhalants can create a risk of freezing burns from contact with the extremely cold liquid (see aerosol burn). the risk of such contact is greatly increased by the impaired judgement and motor coordination brought on by inhalant intoxication. benzene use can cause bone marrow depression. it is also a known carcinogen. toluene can damage myelin. toxicity may also result from the pharmacological properties of the drug; excess nmda antagonism can completely block calcium influx into neurons and provoke cell death through apoptosis, although this is more likely to be a long-term result of chronic solvent use than a consequence of short-term use. sudden sniffing death syndrome sudden sniffing death syndrome is commonly known as ssds. 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 or nitrous oxide) that removes carbon dioxide from the blood without replacing it with oxygen will produce no outward signs of suffocation even when the brain is experiencing hypoxia. once full symptoms of hypoxia appear, it may be too late to breathe without assistance, especially if the gas is heavy enough to lodge in the lungs for extended periods. even completely inert gases, such as argon, can have this effect if oxygen is largely excluded. legal aspects solvent glue contact cement, a fast-drying glue, is widely used as an inhalant, as it typically contains solvents such as toluene which vaporize at room temperature. 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. "thirty-eight of 50 states have enacted laws making various inhalants unavailable to those under the age of 18. other states prohibit the sale of these items to anyone without recognition of purpose for the purchase. some states mandate laws against using these products for purposes of getting high, while some states have laws about possessing certain inhalants. nearly every state imposes fines and jail terms for violation of their specific laws." "connecticut law bans the unauthorized manufacture or compounding, possession, control, sale, delivery, or administration of any "restricted substance". it defines restricted substances as... specific volatile substances if they are sold, compounded, possessed or controlled, or delivered or administered to another person for breathing, inhaling, sniffing, or drinking to induce a stimulant, depressant, or hallucinogenic effect. violators can be fined up to $100." as well, 24 states "ban the use, possession, or sale or other distribution of inhalants... like glue and solvents." "louisiana prohibits the sale, transfer, or possession of model glue and inhalable toluene substances to minors. in ohio, it is illegal to inhale certain compounds for intoxication—a common, general prohibition other states have enacted. some states draw their prohibitions more narrowly... in massachusetts, retailers must ask minors for identification before selling them glue or cement that contains a solvent that can release toxic vapors." propellant gases "new jersey... prohibits selling or offering to sell minors products containing chlorofluorocarbon that is used in refrigerant." poppers main article: poppers a selection of poppers 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. nitrous oxide nitrous oxide "whippets" are small aerosol containers designed for charging whipped cream dispensers. a nitrous oxide "cracker" device, for releasing the gas from whipped cream aerosol chargers. 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