The Japanese Existing and New Chemical Substances Inventory (ENCS) is Japan’s inventory of various different categories of chemical substances. Unlike China’s IECSC, Japan has no standardized existing chemical inventory. Instead, Japan maintains a series of inventories that identify chemicals that are exempt from new chemical notification requirements.

The ENCS is instrumental in the enforcement of the Japanese Chemical Substances Control Law (CSCL) which regulates new chemicals introduced to Japan. ‘New’ chemicals are defined as:

  • Any of the approximately 20,600 substances already manufactured or imported at the time of the enforcement of the CSCL in 1973;
  • Any of the approximately 6,100 substances announced through public notice by the three ministries;
  • Class I and II specified substances;
  • Priority assessment chemical substances;

All existing and notified substances receive a MITI number, which is crucial to customs clearance. A full list of the substances regulated under the CSCL can be found in the NITE’s database at: