Also known as volatile-substance abuse, this is the deliberate inhalation of intoxicating fumes given off by some volatile liquids. Glue-sniffing was the most common type of solvent abuse, but inhalation of fuel gases such as butane, especially in the form of lighter refills, is now a greater problem. Solvents or volatile substances are applied to a piece of cloth or put into a plastic bag and inhaled, sometimes until the person loses consciousness. He or she may become acutely intoxicated; chronic abusers may suffer from ulcers and rashes over the face as well as damage to peripheral nerves. Tolerance to the volatile substances may develop over months, but acute intoxication may lead to aggressive and impulsive behaviour. Death can occur, probably as a result of an abnormal rhythm of the heart. Treatment of addiction is difficult and requires professional counselling. Victims with acute symptoms require urgent medical attention. In Britain, most solvent misusers are males under 20 years of age. Around 150 deaths occur every year in the UK. (See also DEPENDENCE.)