Manufacture of primary cells and primary batteries nd rechargable batteries, cells containing manganese oxide, mercuric oxide silver oxide or other material
Manufacture of structural wooden goods [intended to be used primarily in the construction industry such as beams, rafters, roof struts, glue-laminated and metal connected, prefabricated wooden roof trusses, doors, windows, shutters and their frames, whether or not containing metal fittings, stairs, railings, wooden beadings and mouldings, shingles and shakes etc.]
Operation of sand or gravel pits, basalt / porphyry, clay (ordinary), crushing and breaking of stone for use as a flux or raw material in lime or cement, manufacture or as building material, road metal or ballast and other materials for construction
Manufacture of dental fillings and cements (except denture adhesive or cement), dental wax and other dental plaster preparations; manufacture of dental laboratory furnaces, dental instruments, artificial teeth, bridges, etc., made in dental labs