This standard classifies the environmental conditions to which a product not forming part of the vehicle is subjected when installed in a ground vehicle. Such products are for example radios, communication systems, fare meters, flow meters for liquids transported by the vehicle, for example milk, petroleum products, etc. Vehicles where products may be permanently or temporarily installed include − road vehicles: passenger cars, commercial vehicles, special vehicles, towing vehicles, trailers, mopeds, motor cycles, etc.; − rail vehicles: trains, trams, cranes, etc.; − overland vehicles: four wheel drive cars, tractors, snow scooters, etc.; − handling and storage vehicles: fork-lift trucks (manual and robot), luggage transporters, etc.; − self-propelled machinery: diggers, harvesters, etc. Although this standard is not designed for products forming part of the vehicles, the environmental condition classification may also be used for some exchangeable parts, installed in a similar way and in the same locations of the vehicle as products which do not form part of the vehicle. Only severe conditions which may be harmful to products are included. Conditions of storage and transportation are given in IEC 721-3-1 and IEC 721-3-2. The object of this standard is to classify the environmental parameters and their severities to which a product will be exposed under its conditions of use when installed in ground vehicles. A limited number of classes of environmental conditions are given, covering a broad field of application. The user of this standard should select the lowest class necessary covering each of the conditions of the intended use. Some guidance for this is given in annex A.