Quick search by citation:

19 U.S. Code § 3523 - Duty free treatment for octadecyl isocyanate and 5-Chloro-2-(2,4-dichloro-phenoxy)phenol

The President—
(1)
shall proclaim duty-free entry for octadecyl isocyanate and 5-Chloro-2-(2,4-dichloro-phenoxy)phenol, to be effective on the effective date of the proclamation issued by the President under section 3513(a) of this title to carry out Schedule XX, and
(2)
shall take such actions as are necessary to reflect such tariff treatment in Schedule XX.
Statutory Notes and Related Subsidiaries
Effective Date

Section effective on the date on which the WTO Agreement enters into force with respect to the United States (Jan. 1, 1995), see section 116(a) of Pub. L. 103–465, set out as a note under section 3521 of this title.