There is growing concern that increasingly young children are abusing solvents. The youngest to die was aged nine. Of the current secondary-school population, more than 500,000 - about 10 per cent - are estimated to have sniffed or swallow volatile substances from products such as lighter fuel, aerosols, glue and fire extinguishers. Solvent abuse is the second highest unnatural cause of death (after road accidents) of people aged 10 to 16.
In 1985, the Intoxicating Substances Supply Act was passed, making it an offence to supply anyone under 18 with a substance that the supplier believes will be used to achieve intoxication. At that time the focus was on glue-sniffing, and many shopkeepers refused to sell adhesive products to young people. Since then, deaths from glue abuse have fallen, but fatalities from gas, usually butane in lighter fuel and the propellant in aerosols, have steadily risen. In 1991 more than 60 per cent of deaths were due to gas fuel and aerosols, such as air- fresheners, deodorants, pain relievers and hair-sprays. This compares with just 16 per cent of deaths caused by glue.
One of the new killers is the type of fire extinguisher kept on buses, taxis, and tube trains: 22 people died from sniffing these during 1991 and 1992.
The latest spate of solvent deaths occurred in Sunderland last month, when three youngsters from the same school were found dead in separate incidents. The three were found in burnt-out buildings. Police believe the deaths were the result of experiments with solvents and the teenagers may have started fires to keep warm.
Richard Ives, a solvent consultant with the National Children's Bureau, said: 'Young people are increasingly using aerosols and lighter fuel, partly because they are easier to obtain than glue. The government campaign against glue is a success in one way but a failure in another.'
In an attempt to counter the trend towards butane and other volatile substances, the Department of Health in January launched a pounds 2.5m campaign to encourage parents to talk to their children about drug and solvent abuse. A DoH spokesman said: 'We have moved away from the term 'glue-sniffing' and are stressing that there are many more dangerous substances - there are 30 products that can be sniffed.'
Drug workers have argued for years that more resources should be spent on research into solvent abuse, about which little is known. Researchers stress that far more young people die from taking solvents than all other drugs together. There were seven deaths caused by drugs among people aged under 20 in 1991, compared with 87 from solvent abuse in the same period.
One reason for the high death toll is that youngsters often die during their first experiments with solvents, whereas a fatal reaction to drugs is extremely uncommon. Up to 30 per cent of solvent deaths are of first-time users.
Death is often caused when the solvent makes the heart 'flutter', preventing blood being pumped around the body. Some solvents can also damage the heart, hearing, eyesight, kidneys and liver.
John Ramsey, a research fellow in the toxicology unit at St George's Hospital medical school, London, where the national solvent death statistics are collected, said: 'It's only since we have started collecting accurate data since 1982 that we have begun to discover the real scale of the problem. But because of the lack of research we still have no real idea how many kids sniff substances.'
He added: 'Legislation to outlaw the sale of glue to youngsters appears to have had the effect of making teenagers turn to other solvents, some of them far more dangerous.'
Mr Ramsey believes the producers of lighter fuel should make smaller refills and introduce safety measures to dissuade teenagers from sniffing.
Some manufacturers are taking action - responding to world agreements on reducing the amount of chemicals that deplete the ozone layer. The makers of typewriter correction fluid have started to make sniff- free products which are being promoted in schools.
Scotland, the North of England and Northern Ireland have the highest annual death rates from solvent abuse.
While teenagers are the most likely to die from abuse of solvents, middle-aged and elderly people also use them. The oldest person to die was 76. Older people sometimes use a solvent to obtain a chemical high during sexual activities.
Medical staff and dentists have also died after sniffing anaesthetics, such as 'laughing gas', from their workplace.
For Department of Health booklets and information about solvent abuse, telephone freephone 0800 555777.