A good night's sleep is one of the main concerns of British lorry drivers, according to commercial vehicle security firm Viper Guard.

The Warwickshire-based distributor of locks, alarms, and other safety and security products has just announced its UK sales league table for 2007 - and top of the chart is the Waeco MGS-150 gas alarm.

Gas attacks are causing increasing concern in the industry, says Viper Guard General Manager Debbie Jones. Ether-containing gases or other anaesthetic substances such as trichloroethylene are sprayed into lorry cabs at night, driving sleeping occupants deeper and deeper into unconsciousness. When they come round they find their trailers have been looted or even uncoupled and towed away or, still more frightening, their cab doors have been forced and their personal possessions rifled.

Many of the gases used are lethal in high concentrations, and gas attacks have been implicated in at least two unexplained deaths of lorry drivers, according to independent research commissioned by Viper Guard. To make the problem worse for drivers, says Debbie, the industry has been slow to accept that gas attacks are a reality, and in many cases victims have been suspected of complicity. But with the International Road Transport Union's latest five-year survey of 2,000 drivers recording over 150 gas attacks, she says operators are beginning to recognise the seriousness of the problem.

"Drivers can feel very vulnerable and exposed when they're parked up overnight, and judging by our sales figures the thing they're most worried about is the danger of being gassed as they sleep," she says.

The Waeco MGS-150 is simple to operate - it plugs into the cigarette lighter socket - and emits a loud alarm before the concentration of anaesthetic gas reaches danger levels. "Coupled with our LokGard additional door security, it means that drivers can sleep safe and sound when they pull off the road for the night," says Debbie.

Viper Guard's top 10 sellers are:

1. Waeco MGS-150 gas alarm and LokGard additional door security.
2. Anti-siphon devices.
3. Trailer coupling locks.
4. Trailer door locks.
5. HGV wheel clamps.
6. Pallet stops.
7. ADR Kits.
8. European Travel kits.
9. Cab comfort products.