We have a single 5 litre can of petrol for a lawn mower stored in a metal cabinet in timber shed approximately 5 meters away from the main building. Reading the HSE guidance it would appear that we should be storing such items in a building that is largely non combustible, which the shed isn't. Should the building (shed) be non combustible? Should the shed have a 'Petroleum Spirit - Highly Flammable Liquid' sign on the door or is it OK to say that the metal cabinet inside is non combustible and that it is appropriately signed? There is a reluctance to put a sign on the shed door because this may attract unwanted attention, although I accept it would pre warn fire fighters who may have to attend a fire on site. Does the fact that there is only 5 litres being stored have any bearing on the issue. Comments welcome.

Thanks for the quick reply. The shed is locked. What about signage, is signing the cabinet alone sufficient?