Regulated Precursor Chemicals Act of 1990

Regulated Precursor Chemicals Act of 1990 - Amends the Controlled Substances Act to revise and expand the list of precursor chemicals, including transferring to such list hydriodic acid from the list of essential chemicals. Revises the definition of "regulated transaction" to include transfers of any amount of an essential listed precursor chemical, with exceptions. Requires each regulated person to report to the Attorney General on any regulated transaction involving any quantity of a listed essential chemical. Makes it unlawful for any person to engage in a regulated transaction involving a listed precursor chemical or any other conduct that defines such person as a regulated person for purposes of such Act without a license required under such Act. Requires the Attorney General to establish a program requiring licenses for regulated persons and regulated transactions involving listed precursor chemicals where such requirement will contribute to carrying out the purposes of such Act and to criminal drug law enforcement. Provides for fines and imprisonment of not more than four years for violations of the licensing requirement. Requires the Attorney General to provide for the audit and control of listed precursor chemical inventories of persons possessing a license under this Act. Directs the Attorney General to cooperate with State authorities by providing information regarding regulated transactions in such chemicals that might be useful in the administration of State laws relating to precursor chemicals, controlled substances, and other illegal drugs.