At the molecular level, it has always been a chemical world. But since the 1930s, when the chemical industry began its phenomenal 15 percent annual growth, it has become a synthetic chemical world. Some 250,000 new artificial chemical compounds are invented each year, of which over 500 are introduced into general use; about 10,000 synthetic organic chemicals are already in industrial, commercial and personal use as fuels, lubricants, plasticizers, food additives, feed additives, preservatives, packaging and construction materials, cosmetics, drugs, household convenience products, pigments, aerosol propellants, wearing apparel, and so on. Annual worldwide production of synthetic organic chemicals, which jumped from seven million tons in 1950 to 63 million tons in 1970, is expected to attain 250 million tons by 1985.