37 Building construction and repair; installation of appliances for the purification of fumes; and construction planning
40 Air purification, namely, purification of fumes in incinerating plants for regular and hazardous waste and plants for the disposal of sludge, as well as in power plants, concrete factories, glass factories and other industrial production plants
42 Engineering services; and technical consultation in the field of plants for the purification of fumes from harmful substances, acidic components, and dust, as well as heavy metals in organic substances