Both the House and Senate recently passed a bill which modifies the process for enacting miscellaneous trade bills. Notably, the bill revamps the process for considering duty suspension and reductions found in chapter 99 of the Harmonized Tariff Schedule of the United States (HTSUS.) The revamped process will involve United States manufacturers submitting petitions to the United States International Trade Commission (USITC) which will be followed by a period of public notice and comment and reports created by the USITC regarding qualification. The USITC will then submit the previous information to the appropriate congressional committees which may exclude a suspension or reduction for various reasons, including domestic production.
You can read the House bill here.