- The Bureau of Industry and Security issued a temporary final rule, effective September 22 - December 3, 2026, restricting the stockpiling of polysilicon and polysilicon derivatives until Section 232 polysilicon tariffs and minimum import prices are effective.
- The Department of Commerce will monitor imports of polysilicon and its derivatives against historic average volumes for historical importers, or against weekly caps for new importers, and will restrict U.S. imports exceeding those amounts unless the importer obtains a waiver.
- Waivers will require a detailed application to the Department of Commerce, including information on the importer’s ownership structure, beneficial ownership, polysilicon use (or transfers of polysilicon), estimated import volumes, and a legitimate business purpose for imports exceeding the stockpiling restrictions unrelated to the implementation of the Section 232 polysilicon tariffs.
Importers of raw polysilicon, polysilicon ingots and wafers, solar cells, and solar modules (collectively, “Polysilicon Products”) face new measures intended to restrict stockpiling before December 4, 2026, the date new Section 232 trade remedies (i.e. polysilicon tariffs and minimum import prices) will apply. Specifically, the Bureau of Industry and Security (BIS) has taken action to prevent a surge in Polysilicon Product imports during the period before December 4. The trade remedies were announced in a presidential proclamation released August 6 (for prior coverage, see the trade alert published August 18, 2026 - New Tariffs and Minimum Import Prices on Polysilicon, Derivatives and Solar Products) finding that imports of Polysilicon Products threatened to impair the national security of the U.S.
On September 22, 2026, the BIS issued a temporary final rule (TFR) establishing a framework for the agency to:
- Monitor imports of Polysilicon Products;
- Prohibit imports by companies and their affiliates found to be stockpiling; and
- Establish a process for importers to request waivers from volume restrictions.
The import measures apply immediately through December 3, 2026.
The TFR amends 15 C.F.R. Part 705, which implements the regulations governing Section 232 investigations, reports, and recommendations and introduces Part 705, Supplement No. 1, setting out the requirements waiver application requirements.
Existing Importers: Historical Average Volume Limitations
If a company imported Polysilicon Products before August 6, 2026, and its imports after September 22 are “in volumes substantially greater than their historic averages,” no further imports of those products are permitted before December 4. In practical terms, unless an importer obtains a waiver, volumes above the historical average determined by BIS will trigger a prospective import ban lasting until the Section 232 polysilicon trade remedies take effect.
BIS does not specify how it will calculate each importer’s historic average. The TFR states, however, that BIS will consider the following factors when monitoring imports:
- The importer’s aggregate import volume since August 6, 2026;
- The importer’s weekly average volume since August 6, 2026;
- The importer’s weekly average volume for the period January 1 through August 6, 2026;
- The importer’s weekly average volume during 2025;
- Use of affiliates that do not customarily import Polysilicon Products; and
- Use of new importers to import Polysilicon Products.
These factors indicate that BIS may consider imports by affiliates or third parties in a supply chain when the importer historically entered the goods. The TFR also states that enforcement action will be taken when multiple importers or other arrangements for Polysilicon Product imports are used to circumvent the restrictions. Importers therefore should account for imports of Polysilicon Product by their affiliates and supply chain partners when analyzing historical import activity.
New Importers: Weekly Import Volume Limits
Newly established importers (i.e., importers registered on or after August 6, 2026) that import Polysilicon Products will be monitored against the following fixed weekly volume limits:
| Tariff Code Subheading | Common Description | Weekly Import Limit |
| 2804.61 | Polysilicon | 12 kg |
| 3818.00 (5 of 7 codes) | Polysilicon ingots & wafers | 7 kg |
| 8541.42 | Solar cells | 2,000 No. |
| 8541.43 | Solar modules | 55 No. |
Newly established importers that exceed the applicable weekly import limit will be prohibited from making further entries of Polysilicon Products before December 4, 2026. As with historical importers, exceeding the applicable limit without a waiver will result in a prospective import ban lasting until the Section 232 polysilicon trade remedies take effect.
The TFR states that the weekly limits are based on historical import data and are intended to allow newly established importers to import Polysilicon Products at or below the typical volumes of historical importers. Historical importers therefore may find these weekly limits useful as a reference point when planning near-term supply chain activity.
Waiver Process
Importers subject to restrictions or prohibitions on Polysilicon Product imports can apply for a waiver. Waiver applications must be submitted electronically to the BIS dedicated waiver inbox ([email protected]). The TFR details information that importers must include in a waiver application:
| Section | Section Title | Details |
| 1 | Organization Information |
|
| 2 | Projected Type, Volume, and Use of Imports |
|
| 3 | Legitimate Business Purpose |
|
| 4 | Certification | • Sworn statement under penalty of perjury • Signed by a senior company official • The submission is true, accurate, and complete to the best of the company's knowledge • The company has conducted reasonable diligence to verify the accuracy of the assertions and facts contained in its submissions |
| 5 | Representations & Acknowledgements | • Commitment to not stockpile Polysilicon Products before December 4, 2026 |
| 6 | Additional Information | • Other information the applicant believes is necessary. • If any requested information is not provided, a detailed explanation of why the requirement is inappropriate or inapplicable to the applicant’s circumstances |
The Department of Commerce intends to respond to applications within 14 days of the date of receipt. The waiver application decisions will be individual, and fact- and company-specific for each applicant.
Customs Brokers
The TFR and Supplement No. 1 also expressly prohibit customs brokers entering Polysilicon Products from:
- Filing, procuring, or assisting in the filing of any claim, or of any document, affidavit, or other papers, known by such customs broker to be false;
- Giving, soliciting, or procuring the giving of, any information or testimony that the broker knew or should have known was false or misleading in any matter pending before the Department of Homeland Security (DHS) or to any DHS representative; and
- Taking actions to evade the requirements imposed on them by Supplement No. 1.
The TFR warns that a customs broker’s efforts to evade the prohibition on stockpiling Polysilicon Products may result in Customs and Border Protection (CBP) enforcement action. Potential consequences include proceedings to revoke or suspend the customs broker's license and/or the assessment of penalties.
In assessing whether a newly established importer may be attempting to evade the weekly import limits, customs brokers should consider:
- Whether an importer of record (IOR) is a new IOR that was established on or after August 6, 2026; and
- For new IORs:
- Whether it has made other entries of Polysilicon Products during the current week, and, if so, the precise volume of Polysilicon Products the new IOR has entered;
- The direct and indirect beneficial owners of the new IOR, whether such owners have created other new IORs to import Polysilicon Products, and whether the other new IORs have met or exceeded the quantities specified in table 1 to the supplement; and
- The ultimate consignee and delivery user, and whether the goods will be transferred to or used for the benefit of an IOR subject to a prohibition under this supplement.
Importers using third-party filers should expect customs brokers to request additional documentation regarding ownership and affiliate import activity before accepting new entries of Polysilicon Products.
BIS is now actively monitoring imports of Polysilicon Products for potential stockpiling. Historical importers whose post-August 6 volumes substantially exceed historical averages, and importers established on or after August 6 that exceed the applicable weekly limits, face a heightened risk of enforcement. CBP may prohibit an affected importer of record from making additional entries of covered products through December 3, 2026, before the Section 232 tariffs and minimum import prices take effect on December 4.
The TFR is intended to prevent or deter the stockpiling of Polysilicon Products in advance of the effective date of the Section 232 polysilicon tariffs. Although the TFR was not issued until September 22, BIS will consider import activity beginning August 6, 2026. Companies, therefore, may face exposure based on activity that preceded publication of the TFR. Companies that increased U.S. imports of Polysilicon Products after August 6 should conduct a detailed exposure analysis, account for shipments already in transit when planning imports through December 3 and consider seeking a waiver, if appropriate.
Customs brokers should understand their independent responsibilities under the TFR and amended regulations. They may need to develop or enhance internal controls to identify potentially noncompliant entries and mitigate enforcement risk associated with the Polysilicon Product restrictions.
How BDO Can Help
BDO’s Customs & International Trade Services professionals are tracking implementation of the polysilicon Section 232 stockpiling measures and can assist importers and customs brokers with:
- Comparing current and historical import volumes of Polysilicon Products against the TFR restrictions based on automated ACE import data analysis;
- Assessing the risk of enforcement actions by Commerce or CBP in relation to Polysilicon Product imports;
- Preparing draft waiver applications;
- Assessing options available for compliant Polysilicon Product import volumes on future entries; and
- Developing customs broker or importer controls to prevent high-risk import volumes for future entries.