• Overview
• Types of Inhalants
• Inhalants and their chemical contents
• Dangers of inhalant abuse

• Who's using inhalants?
• Scope of use

Overview

Types of Inhalants

Inhalants can be broken down into three major categories-volatile solvents, nitrites, and anesthetics.

Volatile solvents are either gases, such as butane gas fumes, or liquids, such as gasoline or paint thinner, that vaporize at room temperature. Since the 1950s, the number of common products that contain volatile solvents has increased significantly. Besides gasoline and paint thinner, products with volatile solvents include spray paint, paint and wax removers, hair spray, adroitness, air fresheners, cigarette lighter fuels, analgesic sprays, and propellant gases used in aerosols such as whipped cream dispensers. 

Volatile solvents produce a quick form of intoxication-excitation followed by drowsiness, disinhibition, staggering, lightheartedness, and agitation. Because many inhalant products contain more than one volatile solvent, it is difficult to clearly identify in humans the specific chemical responsible for subsequent brain or nerve damage or death.

Some volatile solvents are inhaled by abusers because of the effects produced not by the product's primary ingredient but by propellant gases, like those used in aerosols such as hair spray or spray paint. Other volatile solvents found in aerosol products such as gold and silver spray paint are sniffed not because of the effects from propellant gases but because of the psychoactive effects caused by the specific solvents necessary to suspend these metallic paints in the spray.

Nitrites historically have been used by certain groups, largely gay men, to enhance sexual experience and pleasure. Often called "poppers' or "rush," some nitrite products are sold as room odorizers. But use of nitrites has fallen off dramatically in recent years. This may be partly because products containing butyl, propyl, and certain other nitrites were banned in 1991, although products using chemical variants of the banned substances are still sold.

For the past 13 years, NIDA's Monitoring the Future survey has adjusted for the underreporting of nitrite use, recognizing that many survey respondents did not include information about nitrite use when answering survey questions about inhalant abuse. That's because most respondents fail to consider the use of nitrites as a form of inhalant abuse, unless prompted with specific questions mentioning "poppers, rush," or other nitrite-specific references, researchers say.

Some observers now believe that adjusting inhalant abuse survey results to combine nitrite use with volatile solvent use can lead to mistaken conclusions when viewing consolidated data over several years. That's because nitrite use is declining while volatile solvent use has been on the rise for a number of years. "In combining solvents with nitrites and then adjusting the data, it appears that inhalant use has not changed over the past 16 years when, in fact, solvent use has steadily increased for a decade and a half and just now may be leveling off," says Dr. Fred Beauvais, a psychologist and NIDA-funded researcher at the Tri-Ethnic Center for Prevention Research at Colorado State University at Fort Collins (see figure).

Because the current inhalant profile lumping nitrites with volatile solvents leads to misleading data and inferences, many researchers believe that a scientific description of inhalant abuse should distinguish abuse of volatile substances from abuse of nitrites and perhaps anesthetics.

Within the other major category of inhalants, the anesthetics, the principal substance of abuse is nitrous oxide. A colorless, sweet-tasting gas used by doctors and dentists for general anesthesia, nitrous oxide is called "laughing gas" because it often induces a state of giggling and laughter. Recent anecdotal reports indicate that nitrous oxide is being sold illicitly to teenagers and young adults at outdoor events such as rock concerts and on the street. Nitrous oxide often is sold in large balloons from which the gas is released and inhaled for its mind-altering effects.

Inhalants and Their Chemical Contents

Volatile Solvents

Adhesives

• Airplane Glue
• Rubber Cement
• Polyvinylchloride (PVC) Cement

Aerosols

• Spray Paint
• Hair Spray
• Deodorant, Air Freshener

Solvents and Gases

• Nail Polish Remover
• Paint Remover
• Paint Thinner
• Typing Correction Fluid and Thinner
• Fuel Gas
• Cigarette Lighter Fluid
• Gasoline

Cleaning Agents

• Dry Cleaning Fluid
• Spot Remover
• Degreaser

Dessert Topping Sprays

• Whipped Cream, Whippets

Nitrites and Anesthetics

Nitrite Room Odorizers

• "Poppers" and "Rush"

Anesthetics

• Gas
• Liquid
• Local

Dangers of inhalant abuse

Although no central system exists in the United States for reporting deaths and injuries from abusing inhalants, several studies have documented the dangers associated with inhalant abuse. A study by Dr. James C. Garriott, the chief toxicologist in San Antonio and Bexar County, Texas, examined all deaths in the county between 1982 and 1988 that were attributed to inhalant abuse. Most of the 39 inhalant-related deaths involved teenagers, with 21 deaths occurring among people less than 20 years old. Deaths of males outnumbered those of females 34 to 5. Many of the abusers met with a violent death possibly related to but not directly caused by the use of volatile solvents. Eleven deaths were caused by suicide (10 by hanging), 9 by homicide, and 10 by accident, including falls, auto accidents, and overdoses.

Most of those people who died in Bexar County had used toluene-containing products, such as spray paints and lacquers, Dr. Garriott reported. The next most frequent cause of death in the Texas study was the use of a combination of chemicals found in typewriter correction fluids and other solvents. Other abused substances that resulted in death included gasoline, nitrous oxide, and refrigerants, such as fluorocarbons (Freon). Freon now has been replaced with butane or propane products in most aerosols.

By starving the body of oxygen or forcing
the heart to beat more rapidly and erratically,
inhalants can kill sniffers

As reported in the Texas study, the solvent toluene, a common component of many paints, lacquers, glues, inks, and cleaning fluids, is identified frequently in inhalant abuse deaths and injuries. A 1986 study of 20 chronic abusers of toluene-containing spray paints found that after one month of abstinence from sniffing the paint, 65 percent of the abusers had damage to the nervous system. Such damage can lead to impaired perception, reasoning, and memory, as well as defective muscular coordination and, eventually, dementia.

In England, where national statistics on inhalant deaths are recorded, the largest number of deaths in 1991 resulted from exposure to butane and propane, which are used as fuels or propellants. Many researchers believe that abuse of butane, which is used in cigarette lighters, is on the increase in the United States. NIDA's Dr. Sharp says, "It's hard to tell whether this is a passing fancy or whether some youthful abusers actually like to get dizzy on the butane and propane gases."

Who's using Inhalants?

One possible reason for the increased use of volatile solvents is that more girls are joining boys in sniffing solvents. "The rates of solvent use for males and females have been converging over the past 20 years," Dr. Beauvais says. Recent studies in New York State and Texas report that males are using solvents at only slightly higher rates than females are. Among Native Americans, whose solvent abuse rates are the highest of any ethnic group, lifetime prevalence rates for males and females were nearly identical, according to 1991 NIDA data.

There is a public perception that inhalant abuse is more common among Hispanic youth than among other ethnic groups. However, recent surveys have not found high rates of abuse by Hispanics in all geographic areas, Dr. Beauvais points out. "It appears that rates for Hispanics may be related to socioeconomic conditions," he says. "As those conditions vary so will the levels of solvent use. Hispanic youths in poor barrio environments may use solvents heavily, but Hispanic youths in less stressful environments do not."

Scope of Use

Inhalant abuse came to public attention in the 1950's when the news media reported that young people who were seeking a cheap "high" were sniffing glue. The term "glue sniffing" is still widely used, often to include inhalation of a broad range of common products besides glue, notes Dr. Charles W. Sharp of NIDA's Division of Basic Research.

With so many substances lumped together as inhalants, research data describing frequency and trends of inhalant abuse are uneven and sometimes contradictory. However, evidence indicates that inhalant abuse is more common among all socioeconomic levels of American youth than is typically recognized by parents and the public. For instance, NIDA's Monitoring the Future survey shows that in 1993, one in every five 8th graders, or 19.4 percent, used an inhalant in his or her lifetime.

Inhalants were used by equally high percentages of 10th and 12th graders, according to the NIDA survey. Lifetime inhalant use among 12th graders, which had increased steadily for most of the 1980s, leveled off somewhat at 17.4 percent in 1993. Also, 17.5 percent of 10th graders reported lifetime inhalant use in 1993.

Inhalants are most commonly used by adolescents in their early teens, with usage dropping off as students grow older. For example, while 5.4 percent of 8th graders reported using inhalants within the past 30 days, known as "current" use, only 2.5 percent of seniors reported current use of inhalants.

A major roadblock to recognizing the size of the inhalant problem is the ready availability of products that are inhaled. Inhalants are cheap and can be purchased legally in retail stores in a variety of seemingly harmless products. As a result, adolescents who sniff inhalants to get high don't face the drug procurement obstacles that confront abusers of other drugs.

Inhalant abuse also appears to be a problem worldwide according to research data presented at a recent NIDA technical review, "Epidemiology of Inhalant Abuse: An International Perspective." According to Nicholas Kozel, of NIDA's Division of Epidemiology and Prevention Research, low price and easy availability and access make inhalants as problematic in Africa, Asia and Latin America as it is in the United States.

Trends in Lifetime Use of Inhalants, Inhalants Adjusted, and Nitrites by High School Seniors, 1979-1993

In surveys of drug use, the category "Inhalants Adjusted" includes the use of nitrites and volatile solvents. Some researchers believe this category leads to misleading conclusions about trends in the prevalence of inhalant use. For instance, the "adjusted" figures from NIDA's 1993 Monitoring the Future survey indicate that inhalant use by high school seniors has been fairly stable since 1979. But nitrite use has gone down dramatically during that period. The true picture of inhalant use, say some observers, is the category "inhalants", which does not include nitrites and which has steadily increased for several years before leveling off.

Inhalant abusers typically use other drugs as well. "Children as young as 4th graders who begin to use volatile solvents also will start experimenting with other drugs, usually alcohol and marijuana," says Dr. Beauvais. "Adolescent solvent abusers are typically polydrug users and are prone to use whatever is available, although they do show a preference for solvents." However, solvent abuse often is held in low regard by older adolescents, who may consider it unsophisticated, a "kid" habit, he adds.