Mobile telephone-toting bankers and investors may be put off entering Kidde's Slough headquarters by the large notice on its entrance gates: 'Please switch off all portable devices'.

This, however, would be a shame. Kidde, as of November 14 the largest independent fire protection business in the world, is a treasure trove, a pyromaniac's paradise of exploding Transit vans, fire extinguishing test rooms and a Firewire tower.