CBP to Block Polysilicon Entries by Flagged Importers Until December 4 Under Anti-Stockpiling Rule

CBP issued implementation guidance for the Commerce Department temporary final rule "Measures to Restrict Stockpiling of Polysilicon and Polysilicon Derivatives Under Proclamation 11052" (Federal Register document 2026-19537, published September 24, 2026). When Commerce notifies CBP that an importer of record is bringing in polysilicon products in volumes substantially greater than its historic average, or that a new importer of record is exceeding the applicable weekly quantity limits set in the rule, CBP will not allow that importer to enter certain polysilicon products for consumption until December 4, 2026. Restricted importers may still move the goods into a bonded warehouse, but may not withdraw them for consumption before December 4. Affected importers may apply to Commerce for a waiver of the prohibition. Covered products, quantity limits, and the waiver procedure are defined in the Commerce rule, questions go to Commerce (Polysilicon232@bis.doc.gov).