Vapours from volatile substances are usually inhaled directly from their containers or from polythene bags.
Drug effect
Vapours from volatile substances pass rapidly from the lungs to the brain causing depression of the central nervous system. Effects similar to acute alcoholic intoxication occur within two to three minutes. Feelings of euphoria are very common and some users report hallucinations. If inhalation (sniffing) continues there is further depression of the central nervous system which leads to loss of awareness, judgement and muscular coordination and eventual coma. The intoxicating effects last for 15-60 minutes after sniffing ceases. Sniffers often report a mild "hangover" for up to a day after use.
Dependency
Tolerance develops so that, over time, larger and larger quantities of volatile substance are required to produce the same effect.
Withdrawal
Occasional mild physical withdrawal symptoms, such as headaches have been noted. However, psychological rather than physical dependence is more common.
Long-term use
Following regular use of volatile substances, "sniffers rash", memory impairment and loss of concentration have been reported. With chronic use, loss of muscular coordination, slurring of speech and vision impairment are common. However, these effects are usually reversible if sniffing stops. Long-term heavy use (ten years or more) may lead to permanent brain damage. A small number of cases involving permanent liver and kidney damage have also been reported.
Overdose risk
Every year there are over 100 deaths in the UK linked to sniffing. Deaths in Northern Ireland are far less frequent but do occur. Over half are linked directly to the toxic effects of substances inhaled. The remainder are caused by a combination of accidents, inhalation of vomit and suffocation caused by a plastic bag over the head.
Pregnancy risks
Volatile substances pass the placental barrier but there is little information about their effects on the foetus.
Legal status
In Scotland, the possession of solvents is not a crime, however the Solvent Abuse (Scotland) Act 1983 makes sniffing of volatile substances grounds for referral to the Childrens Panel. In Northern Ireland, England and Wales, the Intoxicating Substance Supply Act 1985, makes it an offence to knowingly supply solvents for inhalation to anyone under the age of 18 years. In Scotland, Common Law allows for a similar provision. Changes were made to the Consumer Protection Act making it an offence to sell cigarette lighter refills to anyone under 18 with effect from 1 October 1999.
SPECIAL NOTE
In 1997, of all deaths in the UK linked to volatile substances, 69.9% resulted from inhalation of gas fuels (56.2% of gas lighter refills), 13.7% from the inhalation of aerosols and 9.6% from the inhalation of solvent based adhesives.
Following the Montreal Protocol of 1987, it was agreed that certain substances would be phased out of commercial products. These included CFCs, 1-1-1 trichloroethane and bromochlorodifluoromethane (BFC or Halon 12).
Tolerance develops within three months of regular sniffing sessions. Occasional minor physical withdrawal symptoms including headaches.
Long-term use
Chronic users may have "sniffers rash" (usually around mouth and nose) and show impaired performance on memory, intelligence and concentration tests. In most cases, functions return to normal once solvent use ceases.
Toluene has been implicated in reversible impairment of the central nervous system and visual problems. However, in a small number of cases, loss of brain tissue has also been reported.
N-hexane has been linked to visual problems and limb dysfunction, while trichloroethylene has been associated with a small number of cases of liver/kidney damage.
Overdose risk
Thirteen per cent of volatile substance deaths in 1992 involved solvent based adhesives. Toluene is the most common solvent used in glues and adhesives.
Legal status
It is an offence to sell or supply solvents to anyone under 18 years if abuse is suspected.
Volatile substances are inhaled directly from canister or sprayed into a plastic bag and then inhaled.
Dependency
Yes (mainly psychological)
Withdrawal
Tolerance develops with repeated use. Occasional physical withdrawal has been noted.
Long-term use
Aerosol propellants, particularly butane, are thought to sensitise the heart to excitement or exertion. This can cause cardiac failure if the user exerts him/herself during or immediately after use.
Overdose risk
Cooling effects of aerosol sprays on the larynx (back of throat) may make it swell and can cause death by suffocation. As noted, butane has also been linked to sudden death caused by heart failure. For this reason it is advised that sniffers are never startled or chased if they are discovered sniffing.
Legal status
It is an offence to sell or supply solvents to anyone under 18 years if abuse is suspected.
Inhaled directly from container or absorbent material soaked in agent.
Dependency
Yes (mainly psychological)
Withdrawal
Tolerance develops with repeated use. Occasional physical withdrawal has been noted.
Long-term use
Similar to long-term use of adhesives. Trichloro/tetrachloroethane and tetrachloroethylene have also been implicated in a few cases of liver/kidney damage. Carbon tetrachloride is highly toxic and causes liver and brain damage.
Overdose risk
This group of solvents (particularly those containing 1,1,1-trichloroethane) is associated with about one third of solvent-related deaths.
Legal status
It is an offence to sell or supply solvents to anyone under 18 years, if abuse is suspected.
Tolerance develops with repeated use. Occasional physical withdrawal has been noted.
Long-term use
Similar to the long-term use of adhesives. Sniffing petrol has been linked to permanent brain damage. However, it is unclear whether this is due to the hydrocarbons or the tetraethyl-lead added to leaded petrol. Benzene is highly toxic and has been shown to cause bone marrow depression.
Overdose risk
The inhalation of gas fuels (mainly butane) has been linked to about 25% of deaths. However since its use is less common than the inhalation of solvents from adhesives, it appears to be significantly more dangerous. The pressurized gas in both gas lighter fuels and fire extinguishers makes the inhalation of these products extremely dangerous - as with the inhalation of aerosols there is a significant risk of suffocation caused by swelling of the larynx (back of the throat). Butane is also thought to sensitise the heart to exertion which can lead to heart failure.
Legal status
It is an offence to sell or supply solvents or gas lighter refills to anyone under 18 years, if abuse is suspected.
Alkyl nitrites are related to nitrous oxide (laughing gas) and are clear yellow volatile liquids. They are available for sale at some retail outlets and by mail order.
Alkyl nitrites are used mainly by members of the male gay community who inhale volatile fumes to enhance sexual arousal and performance. However, recreational and experimental use has also been reported among other groups of young people.
Drug effect
Alkyl nitrites are vasodilators. They cause dilation of the blood vessels leading to the heart. This is accompanied by a drop in blood pressure and an increase in heart rate. Users report a "rush" and experience euphoria and dizziness. The effects following inhalation are virtually instantaneous and last from two to five minutes. Alkyl nitrites also increase sexual arousal and cause the rectal sphincter to relax, easing anal intercourse.
Dependency
Tolerance develops within two to three weeks if used on a daily basis. However, this is lost following a few days of abstinence. There have been no reports of withdrawal symptoms, either physical or psychological. Hence dependency does not appear to be a problem.
Long-term use
Alkyl nitrites are excreted rapidly from the body and there do not appear to be any serious consequences of long-term use among healthy adults. However, people with a history of heart problems and glaucoma may be at risk because of the increased strain on the cardio-vascular system.
Overdose risk
Excessive use can lead to lack of oxygen in the blood. Users become cyanosed which gives their skin and lips a blue colour. This is usually accompanied by severe vomiting and can lead to clinical shock and loss of consciousness. Deaths have occurred when nitrites have been swallowed.
Legal status
On 13 January 1997 amyl nitrite was reclassified as a prescription-only medicine. Butyl nitrite currently does not come under the Medicines Act.
