Chemical Section

Abstract

The large-scale synthesis of the phosphoric acid esters is a relatively young branch of industry, the development of which is clearly associated with their increasing significance as insecticides in crop protection, beginning after the Second World War. It is difficult to form an exact picture of the production figures because in general there is a delay of 5–10 years before these figures are made known by industry. Thus the last comprehensive compilation of American production was made in 1958 [1004]. According to this report, only 4% of phosphorus production was used for the manufacture of organophosphorus derivatives. However, this still means a total of over 45,000 tons of chemical products, one third of which were insecticides.