Commerce sets temporary anti-stockpiling limits for polysilicon imports
Commerce issued a temporary rule to restrict stockpiling of polysilicon products before December 4, 2026 import adjustments take effect. It allows import prohibitions for existing importers and sets weekly quantity caps for new importers of record.
What this affects
| 2804.61.00 | Polysilicon products, weekly limit for new importers is 12 kg |
| 3818.00.0020 | Polysilicon products, weekly limit for new importers is 7 kg |
| 3818.00.0040 | Polysilicon products, weekly limit for new importers is 7 kg |
| 3818.00.0045 | Polysilicon products, weekly limit for new importers is 7 kg |
| 8541.42.00 | Polysilicon products, weekly limit for new importers is 2,000 No. |
| 8541.43.00 | Polysilicon products, weekly limit for new importers is 55 No. |
Codes are a starting point, not a classification. Confirm your own 10-digit HTS before you rely on a rate, using our HTS classification guide.
Key dates
- December 3, 2026Temporary anti-stockpiling limits endNext
The update
This temporary final rule sets the process Commerce will use to restrict stockpiling of polysilicon and polysilicon derivatives before separate import adjustments take effect on December 4, 2026. It applies from September 22, 2026, through December 3, 2026. The rule lets Commerce monitor importers of record, bar further entries where it finds stockpiling, and administer waivers.
For existing importers of record, Commerce will monitor imports and can direct CBP to stop further entries before December 4, 2026 if volumes are substantially greater than historic averages. The rule says Commerce will make a fact-specific decision using factors such as aggregate imports since August 6, 2026, weekly averages since that date, prior 2026 and 2025 weekly averages, and use of affiliates or new importers of record.
For new importers of record that registered with CBP on or after August 6, 2026, the rule bars imports above specified weekly quantities unless Commerce approves a waiver. The listed limits are 12 kg for HTSUS 2804.61.00, 7 kg for HTSUS 3818.00.0020, 3818.00.0040, 3818.00.0045, 3818.00.0050, and 3818.00.0091, 2,000 No. for HTSUS 8541.42.00, and 55 No. for HTSUS 8541.43.00. Commerce says it may adjust these volumes later if needed to address stockpiling.
Companies subject to a prohibition or restriction may apply to Commerce for a waiver, with organizational, ownership, volume, use, and business-purpose information, plus a certification and a commitment not to stockpile. Commerce says it intends to respond within 14 days of receipt. The rule also reminds customs brokers of their obligations and says facilitation of evasive arrangements may trigger CBP enforcement action.
Impact
This rule can interrupt supply before the December 4, 2026 tariff and minimum import price changes even though it does not set a new duty rate itself. Importers using new entities, accelerated shipments, or unusual volume spikes may face blocked entries, tighter documentation demands, and added cash flow and planning risk during the interim period.
What to watch
The rule does not define a single numerical threshold for when an existing importer is deemed to be stockpiling, so outcomes depend on Commerce's company-specific review. It also says Commerce may adjust the weekly quantity limits for new importers, and the underlying December 4, 2026 import adjustments are referenced but not detailed here.
How to prepare
- 1Review importer of record setup
Confirm whether entries are being made under an existing or newly registered importer of record.
- 2Pull recent entry volume data
Compare post-August 6 shipments against prior weekly averages to spot stockpiling risk.
- 3Check HTS classifications used
Validate whether entries fall under the subheadings named in the rule.
- 4Gather origin and ownership records
Keep documentation ready in case Commerce requests support for a waiver or review.
- 5Coordinate closely with customs broker
Brokers need visibility into weekly volumes and importer relationships during the temporary rule period.
Sources
- Measures To Restrict Stockpiling of Polysilicon and Polysilicon Derivatives Under Proclamation 11052 · Federal Register · September 24, 2026
We summarize published reporting and official notices. Always confirm rates and dates against the Federal Register or your customs broker before acting on them.