The purpose of the Act on the Evaluation of Chemical Substances and the Regulation of Their Manufacture. (Kagakubusshitsu no Shinsa oyobi Seizoto no Kisei nikansuru Horitsu, Law no 117 of 1973, the Chemical Substances Control Law) is to control the manufacture and importation of chemical substances which might affect the natural environment or human health. Under the Chemical Substances Control Law, notifications are required for the manufacture or importation of new chemical substances. However, notifications are not required for the manufacture or importation of existing chemical substances, which are comprised of approximately 20,000 different types of substance and had already existed at the time the Chemical Substances Control Law was established in 1973.