Phenol is used today chiefly as a component of tar-acid resins. It is also widely used as an antiseptic and disinfectant, in the manufacture of explosives (picric acid and ammonium picrate), and as an intermediate for certain dyes and medicinals. Salicylic acid and its derivatives—aspirin, salol, and methyl salicylate (artificial oil of wintergreen)—are important medicinals made from phenol. Another use is in the extraction of lubricating oils. The relative importance of these various uses in recent years is indicated by table 58, which gives the estimated domestic consumption of phenol by uses in 1936-37. TABLE 58.—_Phenol: Estimated consumption by industries, 1936-37_ ------------------------------+----------------- Use |Percent of |total consumption ------------------------------+----------------- Synthetic resins | 60-65 Extraction of lubricating oil | 5 Insecticides and disinfectants| 10 Dyes and intermediates | 5 Other | 15-20 ------------------------------+----------------- United States production. Prior to 1914 United States production of phenol averaged about a million pounds a year and was entirely the natural product obtained from distillates of coal tar. Increased demand during the World War was met by several synthetic phenol processes, which utilized in part the vast quantities of benzol available. Our output of phenol reached 64 million pounds in 1917 and 107 million pounds in 1918. When the armistice was signed stocks on hand in the United States totaled between 35 million and 40 million pounds, estimated at three times the annual consumption at that time for nonmilitary purposes. As a result the price dropped from about 45 cents to 6 cents a pound, and the synthetic plants were closed. The limited quantities of phenol available to synthetic resin makers prior to and during the World War caused much concern to that industry and led to research work for substitutes, work resulting in the development of many new and modified types of resins in which tar acids other than phenol were used. But notwithstanding the use of these other tar acids the increased demand for synthetic resins used up the accumulated stocks of phenol sooner than was expected. Of the phenol produced in the United States from 1919 through 1923 a large part was natural phenol but the rapid increase in demand and the improvement of processes for synthetic phenol had by 1923 resulted in four companies beginning production of the synthetic article. The rapid increase in output, from about 3 million pounds in 1923 to about 15 million pounds in 1925, was almost entirely in synthetic phenol. Since then a large part of the domestic production has continued to be synthetic, although the production of natural phenol since 1935 has been about four times that of 1929.