SCIENTISTS from York are developing rapid tests for explosives and toxins in liquids that could help in the war against terror.

Experts from the Central Science Laboratory are helping the water industry to check - often in a matter of minutes - whether drinking water has been contaminated.

The same techniques could be used in future to check food samples for contamination.

Other scientists at the labs are also working on a new test for viruses, such as rabies, bird flu and foot and mouth disease, which could cut the time taken to confirm an outbreak from up to ten days to only a few hours.

A biochip being developed at the labs will be able to save time and resources in the event of an outbreak, and also quickly identify when a virus has jumped from one species to another and when new strains of disease emerge.

The CSL, based alongside the A64 at Sand Hutton, near York, is an executive agency of the Department for Environment, Food and Rural Affairs (Defra), but nowadays provides services to most Government departments.

The explosives checks have been developed using the lab's Nuclear Magnetic Resonance (NMR) equipment, bought for £600,000 several years ago in conjunction with the University of York. Dr Adrian Charlton, head of NMR, said today that the process had been developed and improved in support of existing activities aimed at detecting the occurrence of chemical contamination incidents.

One such scenario was last summer's security scares at airports, when police believed terrorists intended carrying liquid explosives on board planes in their hand luggage and travellers suffered massive delays and disruption.

He said this had illustrated the importance of being able to detect unknown contaminants in liquids in an emergency.

"To be of any real value in emergency situations, analytical techniques have to be rapid, sensitive, and effective across a wide range of unknown contaminants and in many emergency scenarios," he said.

But the water industry was also concerned about the potential for contamination of drinking water supplies, and CSL has taken part in joint exercises with the water companies' own labs to ensure readiness to respond to an emergency incident.

Test samples had been contaminated at the CSL with unknown substances, and then sent to the water companies and to the NMR unit for analysis to determine what the contaminant was.

The NMR had been able to detect the contaminants in hours and supported findings from the water labs.