Mercury thermometers will become a thing of the past in hospitals within the next few years if trends favouring alternative devices continue. NHS Supplies, the special health authority which provides goods and services for the NHS, says the number of mercury thermometers in use in hospitals almost halved during the past five years.
In 1990, 1.5 million thermometers were used nationwide, but this year the total is 800,000.
High street chemists also report a demand for non-mercury thermometers, especially from parents buying instruments for their children, although the UK's biggest chain, Boots, is not phasing out mercury-based ones.
If the trend away from mercury thermometers continues, they could vanish from hospital wards within the next five or six years, marking the end of a 280-year era. The first successful mercury thermometer was created in 1714 by Gabriel Fahrenheit and they eventually became commonplace in hospitals.
One leading campaigner against their use, Dr Ivan Blumenthal, from the Royal Oldham Hospital near Manchester, has argued that there are high risks of breakage and poisoning, and of them spreading infection between patients because they are re-usable.
"Everybody has become very conscious about mercury floating about, especially in neo-natal departments," he said.
"People feel that if we could use an alternative that was as accurate, why not switch?"
Among the alternatives is the Tempadot, a plastic strip thermometer containing organic chemicals in various quantities which release a blue dye when they reach their different melting points, indicating a patient's body temperature.
Manufacturers of the Tempadot say it is just as accurate as its mercury predecessor - to within 0.1C - but it is yet to be officially tested.
However, a recent study in Nursing Times found that disposable thermometers are more accurate, cheaper and quicker than mercury devices. The study, by a clinical nurse specialising in medicine for the elderly at the Royal Bournemouth Hospital, questioned current nursing practice and the safety of the tools being used in hospitals.Reuse content