Commonly Abused Inhalants

What are
inhalants?

Inhalants are volatile substances that produce chemical vapors that can be inhaled to induce a psychoactive, or mind-altering, effect. Although other abused substances can be inhaled, the term "inhalants" is used to describe a variety of substances whose main common characteristic is that they are rarely, if ever, taken by any route other than inhalation. This definition encompasses a broad range of chemicals found in hundreds of different products that may have different pharmacological effects. As a result, precise categorization of inhalants is difficult. One classification system lists four general categories of inhalants - volatile solvents, aerosols, gases, and nitrites - based on the form in which they are often found in household, industrial, and medical products.

Volatile solvents are liquids that vaporize at room temperatures. They are found in a multitude of inexpensive, easily available products used for common household and industrial purposes. These include paint thinners and removers, dry-cleaning fluids, degreasers, gasoline, glues, correction fluids, and felt-tip marker fluids.

Aerosols are sprays that contain propellants and solvents. They include spray paints, deodorant and hair sprays, vegetable oil sprays for cooking, and fabric protector sprays.

Gases include medical anesthetics as well as gases used in household or commercial products. Medical anesthetic gases include ether, chloroform, halothane, and nitrous oxide, commonly called "laughing gas." Nitrous oxide is the most abused of these gases and can be found in whipped cream dispensers and products that boost octane levels in racing cars. Household or commercial products containing gases include butane lighters, propane tanks, whipped cream dispensers, and refrigerants.

Nitrites often are considered a special class of inhalants. Unlike most other inhalants, which act directly on the central nervous system (CNS), nitrites act primarily to dilate blood vessels and relax the muscles. While other inhalants are used to alter mood, nitrites are used primarily as sexual enhancers. Nitrites include cyclohexyl nitrite, isoamyl (amyl) nitrite, and isobutyl (butyl) nitrite, and are commonly known as "poppers" or "snappers." Amyl nitrite is used in certain diagnostic procedures and was prescribed in the past to treat some patients for heart pain. Nitrites are now prohibited by the Consumer Product Safety Commission, but can still be found, sold in small bottles, often labeled as "video head cleaner," "room odorizer," "leather cleaner," or "liquid aroma."

Students who have ever used inhalants versus other commonly abused drugs, percent

What are the
patterns of
inhalant abuse?

Inhalants - particularly volatile solvents, gases, and aerosols - are often among the first drugs that young children use. One national survey indicates that about 3.0 percent of U.S. children have tried inhalants by the time they reach fourth grade. Inhalant abuse can become chronic and extend into adulthood.

Generally, inhalant abusers will abuse any available substance. However, effects produced by individual inhalants vary, and some individuals will go out of their way to obtain their favorite inhalant. For example, in certain parts of the country, "Texas shoe-shine," a shoe-shining spray containing the chemical toluene, is a local favorite. Silver and gold spray paints, which contain more toluene than other spray colors, also are popular inhalants.

Data from national and State surveys suggest inhalant abuse reaches its peak at some point during the seventh through ninth grades. In the Monitoring the Future (MTF) study, an annual NIDA-supported survey of the Nation's secondary school students, 8th-graders also regularly report the highest rate of current, past year, and lifetime inhalant abuse; 10th- and 12th-graders report less abuse.

Percent of 8th-Graders Reporting Lifetime Use of Inhalants Increased

Gender differences in inhalant abuse have been identified at different points in childhood. The 2004 MTF indicates that 10.5 percent of 8th grade females reported using inhalants in the past year, compared with 8.8 percent of 8th grade males. Among 12th- graders, 3.4 percent of females and 4.8 percent of males reported using inhalants in the past year. The National Survey on Drug Use and Health (NSDUH), an annual survey of drug use among the Nation's noninstitutionalized civilians, reports that similar percentages of 12- to 17-year-old boys and girls abused inhalants in 2003. However, the percentage of 18- to 25-year-old males who abused inhalants within the past month was more than twice that of females in that age group, suggesting that sustained abuse of inhalants is more common among males.

People who abuse inhalants are found in both urban and rural settings. Research on factors contributing to inhalant abuse suggests that adverse socioeconomic conditions, a history of childhood abuse, poor grades, and dropping out of school all are associated with inhalant abuse.

How can inhalant abuse be recognized?

What is the
scope of
inhalant abuse?

Inhalant abuse was up significantly for the second year in a row among 8th-graders, according to the latest MTF data, while use among 10th- and 12th-graders continued to decline.

• The rate of high school seniors who abused inhalants in the past year was 4.2 percent in 2004, down from the peak of 8.0 percent in 1995.
• Annual abuse of inhalants among 10th-graders was 5.9 percent in 2004, also down from a high in 1995 (9.6 percent).
• Among 8th-graders, 2004 abuse figures, at 9.6 percent, were down overall from the 1995 peak of 12.8 percent, but were up from the 2002 rate of 7.7 percent.

According to the 2003 NSDUH, lifetime, past year, and past month inhalant use among persons aged 12 to 17 were 10.7 percent, 4.5 percent, and 1.3 percent, respectively. The number of new inhalant users increased from 627,000 new users in 1994 to 1 million in 2002. Inhalant initiates were predominantly under age 18 (78 percent in 2002).

MTF's lifetime prevalence figures indicate that the percentages of students who have tried inhalants continue to decrease steadily for 10th- and 12th-graders. In 2004, 12.4 percent of 10th-graders and 11.9 percent of 12th-graders said they have abused inhalants at least once in their lives. Although lifetime prevalence peaked for 8th-graders in 1995 (21.6 percent), rates of inhalant use among this group are still high. In fact, 8th-graders reported a significant increase in lifetime use from 15.8 percent in 2003 to 17.3 percent in 2004. For 10th-graders, the peak was 19.3 percent in 1996. For seniors, rates were highest in 1994 at 17.7 percent. These data raise a question: How can fewer 12th-graders than 8th-graders consistently report they have ever abused inhalants? Possibly, many 12th-graders fail to recall their much earlier use of inhalants or, more troubling, many 8th-grade inhalant abusers may have dropped out of school by the 12th grade and are no longer included in the survey population.