Inhalants are a chemically diverse group of psychoactive substances composed of organic solvents and volatile substances commonly found in more than 1000 common household products, such as glues, hair spray, air fresheners,gasoline, lighter fluid, and paint. While not regulated in the United States under the Controlled Substances Act, many states have placed restrictions on the sale of these products to minors.

Inhalants may be sniffed directly from an open container or "huffed" from a rag soaked in the substance and held to the face. Alternatively, the open container or soaked rag can be placed in a bag where the vapors concentrate before being inhaled. Although inhalant abusers may prefer one particular substance because of the odor or taste, a variety of substances may be used because of their similar effects, availability, and cost. Once inhaled, the extensive capillary surface of the lungs allows rapid absorption of the substance, and blood levels peak rapidly. Entry into the brain is so fast that the effects of inhalation can resemble the intensity of effects produced by intravenous injection of other psychoactive drugs.

The effects of inhalant intoxication resemble those of alcohol inebriation - stimulation and loss of inhibition, followed by depression. Users report distortion in perceptions of time and space. Many users experience headache, nausea or vomiting, slurred speech, loss of motor coordination, and wheezing. A characteristic "glue sniffer's rash" around the nose and mouth may be seen. An odor of paint or solvents on clothes, skin, and breath is sometimes a sign of inhalant abuse.

Sniffing highly concentrated amounts of the chemicals in solvents or aerosol sprays can directly induce heart failure and death. They also cause death from suffocation by displacing oxygen in the lungs and then in the central nervous system, causing breathing to cease. The chronic use of inhalants has been associated with a number of serious, long-term, and often irreversible health problems. These include hearing loss, brain and central nervous system damage, bone marrow damage, liver and kidney damage, and blood oxygen depletion.

Inhalant abuse is shockingly common among children and adolescents. In a 1998 survey by the National Parents' Resource Institute for Drug Education, 2.2 percent of fourth graders and 2.7 percent of sixth graders admitted to sniffing glue and other inhalants on a monthly basis. By the time they reach the eighth grade, 5.0 percent will be using inhalants monthly, and 19.7 percent will have used inhalants at least once in their lifetime, according to statistics from the 1999 Monitoring the Future study. Inhalants are readily available, inexpensive, and easy to conceal. Therefore, they are increasingly popular with young people and are, for many, one of the first substances abused. The extent of the inhalant problem among children and adolescents was, at first, virtually unrecognized by the general public. However, a event in early 1999 called national attention to this severe problem. Five high school girls were killed in a car accident outside Philadelphia, and the coroner's report showed that four of the five, including the driver, had ingested "significant" amounts of a computer keyboard cleaner. Since this event, there has been an increased awareness of the threat of inhalant abuse.

(cut'n'paste from http://www.dea.gov/concern/inhalants.htm)