(Also called solvent abuse, volatile organic solvent abuse, sniffing, huffing or bagging)
Martin J. Smilkstein, M.D.
Associate Professor of Toxicology
Oregon Health Science Center
Inhalants are chemicals or vapors that can be breathed to get high. Although one of the most common and important types of substance abuse, inhalants are often overlooked in discussions of important or dangerous drugs. In fact, when compared to other drugs, inhalants are unique and maybe more important for several reasons:
1. Inhalants are legal, inexpensive and easily found in stores, homes, schools and workplaces
2. Inhalant abuse is most common in children, pre-teens and young teens
3. Because they are legal and familiar, the substances used are mistakenly thought of as safe
4. Among young teens, deaths from inhalant abuse are more common than from other forms of drug abuse, and occur after even one-time or casual use
For these reasons, even though inhalants often get relatively little attention when drug use is discussed, it is essential that the nature of these substances and the effects and dangers of this very common form of abuse are clearly understood.
Inhalants include a wide variety of substances which are either gasses, or that give off vapors or fumes which can be inhaled (see table). Examples include adhesives (airplane glue, rubber cement, PVC cement), aerosols (spray paint, hair spray, deodorant, air freshener), solvents and fuels (nail polish remover, paint remover, paint thinner, type correction fluid, fuel gas, cigarette lighter fluid, gasoline), cleaning agents (dry cleaning fluid, spot remover, degreaser), dessert topping sprays (whipped cream, whippets), room odorizers (poppers, rush), and medical anesthetics (nitrous oxide [laughing gas], halothane, chloroform).
Although inhalant use dates back to the ancient Greeks and to chloroform or nitrous oxide parties in the 1800s, it was glue sniffing in the 1950s that first led to notoriety in the United States. The popularity of various inhalants changes over time in unpredictable patterns. Geographic location, cultural differences, availability of ingredients, scent, information and misinformation about potency, and other unknown factors all may play a role. The use of certain products may become preferred, as in the case of toluene-containing Texas Shoe Shine, or preference for certain colors or types of spray paint. Use of gasoline or toluene (often in spray paints) have remained common; freons and other fluorocarbons have become harder to find due to environmental regulations; ingredient changes in type-correction fluid has decreased its abuse. Although precise current use patterns can not be predicted, butane (particularly cigarette lighter fluid) has caused most recent reported deaths.
Product Chemicals Adhesives Airplane glue Toluene, ethyl acetate Rubber cement Hexane, toluene, methyl chloride, acetone, methyl ethyl ketone, methyl butyl ketone Trichloroethylene Aerosols Spray paint Toluene, butane, propane, fluorocarbons (freon), hydrocarbons Hair spray Butane, propane, fluorocarbons Deodorants, air fresheners Butane, propane, fluorocarbons Analgesic or asthma sprays Fluorocarbons Solvents and fuels Polish remover Acetone Paint remover Toluene, methylene chloride, methanol Paint thinners Toluene, methylene chloride, methanol Type correction fluid Trichloroethylene, trichloroethane Fuel gas Butane Lighter fluid Butane, isopropane Gasoline Many hydrocarbons Fire extinguisher propellant Bromochlorodifluoromethane (halon), fluorocarbons Cleaning agents Dry cleaning fluid Tetrachloroethylene, trichloroethane Spot removers Tetrachloroethylene, trichloroethane, trichloroethylene Degreasers Tetrachloroethylene, trichloroethane, trichloroethylene Dessert topping sprays Whipped cream Nitrous oxide Whippets Nitrous oxide Room odorizers Locker room, rush, poppers Isoamyl nitrite, isobutyl nitrite, isopropyl nitrite, butyl nitrite Medical anesthetics Gasses Nitrous oxide Liquids Halothane, enflurane, chloroform Local Ethylene chloride
Toluene, ethyl acetate
Hexane, toluene, methyl chloride, acetone, methyl
ethyl ketone, methyl butyl ketone
Toluene, butane, propane, fluorocarbons (freon), hydrocarbons
Butane, propane, fluorocarbons
Deodorants, air fresheners
Butane, propane, fluorocarbons
Analgesic or asthma sprays
Solvents and fuels
Toluene, methylene chloride, methanol
Toluene, methylene chloride, methanol
Type correction fluid
Fire extinguisher propellant
Bromochlorodifluoromethane (halon), fluorocarbons
Dry cleaning fluid
Tetrachloroethylene, trichloroethane, trichloroethylene
Tetrachloroethylene, trichloroethane, trichloroethylene
Dessert topping sprays
Locker room, rush, poppers
Isoamyl nitrite, isobutyl nitrite, isopropyl nitrite, butyl nitrite
Halothane, enflurane, chloroform
Some substances or their vapors can be sniffed, snorted or inhaled directly, but often other methods are used. Bagging is a term used to describe placing the substance in a plastic bag with the opening of the bag over the nose and/or mouth and inhaling repeatedly. Huffing is placing a rag soaked in the substance in or over the mouth and then inhaling. The many forms of these substances, dispensers and containers have led, and will lead, to many other methods of use, as well.
Patterns of use: Who uses inhalants?
Inhalant abusers may be thought of in three groups: hard-core, longterm, adult inhalant-dependent users; polydrug users; and young users. Members of the first group are the least common but are the group which shows severe, irreversible brain and organ damage from years of heavy use. They often abuse other substances, but prefer inhalants when available. The second group is similar to other polydrug abusers, but use inhalants as a low-cost, readily available substitute when other drugs or alcohol are unavailable. All sociocultural groups are represented, but inhalant use in these older age users is clearly more common in lower socioeconomic groups, particularly among certain Hispanics and Native American communities.
The young user is generally just entering an experimentation period, often having tried tobacco, alcohol or marijuana, and finds inhalants easy to obtain and use. Young users are common in all socioeconomic groups, and are most often white males. Estimates of use vary, but all among teens 12-17 years of age, more than 15% have used inhalants at least once; in certain high risk groups this number approaches 50%. First use is often very young, some surveys finding that 5% of 4th graders have tried an inhalant, with most users starting around age 12-14. The 1997 NIDA MTF* study found that 21% of 8th graders had used inhalants at least once. Despite these numbers, the relative importance of inhalant abuse remains largely unrecognized by parents, educators and health professionals when counseling preteens and teens.
Subtle differences between the high from different inhalants do exist, but as a group the effects are best thought of as similar to rapid alcohol intoxication. After inhalation, these chemicals are rapidly absorbed into the bloodstream from the lungs, quickly travel to the brain, causing a quick onset high. Lightheadedness, excitation, giddiness, and loss of inhibitions are initial effects which often progress to dizziness, drowsiness or agitation. At higher levels of intoxication, difficulty with balance and speech, disorientation, and occasional bizarre behavior or hallucinations have been noted. At very high doses, loss of consciousness may occur and breathing may decrease or even cease. After use, headache and lethargy typical of an alcohol hangover is common.
Because the high from an inhalation is very short-lasting (only a few minutes), and the after effects often unpleasant, the most common pattern of use is to do repeated frequent inhalations in order to maintain the high. This leads to higher doses and greater chance of dangerous toxic effects. In addition, the desire to intensify or prolong the high often leads to attempts to affix a bag, rag or other drug delivery device over the face and these attempts are commonly the main or contributing cause when inhalant deaths occur.
Effects of inhalants: dangerous health effects
The acute and chronic toxic effects of inhalants should be considered separately. Acute effects occur during or soon after use and occur even after first-time or casual use, so are common in the young user. Chronic effects are much less common except in long-time or extremely heavy users and are therefore much more likely in older users.
Most health care practitioners will never see the acute effects of inhalant use, but not because problems do not occur. Quite the opposite. The most important acute health effect of inhalant abuse is death (sometimes called sudden sniffing death), and victims almost never reach a health care facility alive. Death usually results from either sudden cardiac arrest, or suffocation. The best current evidence suggests that certain inhalants, (for example, fluorocarbons, butane) sensitize the heart so that deadly irregular heartbeats (ventricular fibrillation) can be triggered by events which would normally be harmless. When this occurs, the normal release of adrenaline into the bloodstream which happens after things like excitement, exertion, or fear may trigger lethal heart rhythms in users, so that sudden death occurs without any warning. Victims suddenly lose consciousness or show other signs of sudden cardiac arrest (irregular breaths, twitching, etc.) but because of a lack of awareness of this danger, friends or witnesses often believe the victim to be joking or experiencing only minor problems. Sometimes victims collapse with no one around and other times there is a delay in calling 911, but even when resuscitation efforts are started soon, survival is uncommon. It can not be overemphasized that inhalant-induced sudden cardiac death may result from even one-time use, does not require overdosage, and is not preventable by anything other than abstinence. In the 1999 fatality report of the A.A.P.C.C., the ages of those dying after inhalant use were 12 to 19 old, with most under 16.
Suffocation or asphyxiation is most often the result of the method used to inhale the substance. Ordinarily, users regulate the dose of the agent by ceasing inhalation, or by intermittent inhalations, and they get oxygen between inhalations. Baggers may place their head in the bag or attach the bag over their nose and mouth. The resulting combination of a high dose of inhalant and less oxygen often results in loss of consciousness. When this occurs with the bag in place, suffocation results. Other methods of inhalation can cause the same result. Choking on rags or on vomit has also occurred. A rarer cause of asphyxiation is airway obstruction from swelling produced by direct spraying of certain agents into the mouth. This may result from direct irritation or unpredictable reactions, but has also occurred from cold-induced injury after inhalation of fire extinguisher halons and other similar chemicals.
As with other drugs or alcohol, deaths also have occurred from trauma, presumably related to altered behavior and judgment while intoxicated.
Other acute effects and chronic effects are varied and depend on the agent used. The following summary is not intended to be complete, but lists some of the most important known effects. Treatment recommendations are available immediately at any time from any Regional Poison Center:
Other acute effects
Blood: Nitrites (e.g., amyl nitrite, isobutyl nitrite) can change normal blood hemoglobin to methemoglobin which does not carry and deliver oxygen normally to tissues. Elevated methemoglobin levels cause cyanosis (bluish appearance to nailbeds and skin), but more importantly causes signs of inadequate tissue oxygen (e.g., shortness of breath, dizziness, loss of consciousness, etc).
Liver: Several chlorine-containing solvent inhalants (e.g., trichloroethylene, chloroform, halothane) are toxic to the liver, causing anything from mild hepatitis to fulminant liver failure and death.
Kidney: Chloroform, methylene chloride, trichloroethylene and others may cause acute kidney failure, although it is rare and usually only after massive overdose in occupational settings.
Other chronic effects
Nervous system: Severe, permanent brain damage may be possible from many inhalants, but is most clearly related to long-term, heavy use of toluene-containing inhalants. Loss of coordination, loss of balance, loss of memory and thinking ability may all occur, often resulting in total disability. Many other abnormalities are also seen including loss of smell, hearing damage, shakiness, and other forms of nerve damage. Several inhalants have caused permanent nerve damage causing loss of feeling and coordination in hands, arms, feet and legs. Fortunately, most of these agents (n-hexane, methyl butyl ketone) are not readily available. A readily available inhalant that can cause nerve damage is nitrous oxide (laughing gas, whipped cream whippets). Gasoline represents a special problem. Brain and nerve damage is seen in heavy users and probably can be caused by the gasoline alone, but inhaling leaded gas has caused the additional problem of lead poisoning. A variety of other forms of brain and nerve abnormalities may have occurred from other inhalants, but those mentioned here are the best known.
Kidney: Toluene has been associated with many kidney problems, but the most common is renal tubular acidosis. When this occurs, the kidney loses its ability to control the chemical balance in blood, resulting in life-threatening loss of potassium and dangerous accumulation of acid.
Pregnancy and the newborn: Because of poor nutrition, other drug use and other factors in mothers who abuse inhalants during pregnancy, it is hard to know which problems are due to the inhalants. Birth defects and growth problems in newborns have occurred.
Unfortunately, the only way to prevent acute toxic inhalant effects is to avoid using inhalants. Unlike most other drugs or alcohol, the dangers of which can be decreased by control of dose or choice of agent, no safe inhalant has been identified and death can occur even with first-time use and low dose use. Inaccurate rumors that certain agents or certain methods of use are safe are common, and have led to deaths. While it is clear that some agents and some methods of use are more dangerous, none have been shown to be safe. Spreading this information has been particularly difficult since these agents are legal, cheap, available and the deaths that have occurred have not been widely publicized. Certainly, most people who use inhalants do not die, in fact only a very tiny fraction do. Although users are rarely aware of the risk, death is totally unpredictable and they are just as likely to die as anyone else. Sadly, using the most commonly abused inhalants, at all, is to risk death.
Most young inhalant users experiment with these agents and then quit, thus avoiding the risk of chronic effects. Others who begins to use inhalants many hours a day, or many days in a row, or many days in a month, or for several years risk damage that may not be reversible. Discontinuing use and detoxification after heavy use can be very difficult so specialized counseling and detox help is important.
Many organizations are concerned about the risks of inhalant abuse and are working to make information available:
1. National Institute on Drug Abuse: www.drugabuse.gov
2. National Clearinghouse for Alcohol and Drug Information: www.health.org, 1-800-729-6686
3. National Inhalant Prevention Coalition: www.inhalants.org, 1-800269-4237