Use Class 2 is for end uses where wood is used indoors, above ground and within the building envelope, but with an occasional risk of wetting (from plumbing leaks for example).
Consumer and contract law require that any product offered for sale must be fit for its intended use and a wood product impregnated with preservative is no exception. The minimum standards for the treatment of wood are set out in British Standard BS8417 (Preservation of Wood: Code of Practice). In...