640	CHEMICAL INDUSTRY. MINING. METALLURGY
643	Glass industry. Ceramics industry. Cement industry
645	Metals. Metallurgy
646	Mining and mining industry
648	Chemical industry
649	Organic chemicals industry
649.1	Coal. Peat
649.2	Oil. Natural gas
649.5	Plastics and rubber industry
649.9	Biotechnology
649.91	Food industry. Coffee. Tea. Alcoholic beverages. Tobacco