The 2026 Section 301 tariff exempts silicones in primary forms only for pharmaceutical use

A quote for a silicone fluid or siloxane that gives a price without the HTS line, the country of origin and the end use cannot be ranked against another quote for a lot entered from July 24, 2026.

From 12:01 a.m. eastern time on July 24, 2026, the forced-labor Section 301 action of the Office of the United States Trade Representative (USTR), published at 91 FR 47318 on July 28, 2026, adds 12.5% on products of China and 10% on products of India. Note 52 lists silicones in primary forms and the organo-silicon compounds of 2931.90.90 only in its pharmaceutical-use exemption, so the same China- or India-origin lot can owe the new duty or not depending on its end use, and a price-only quote shows neither.

Checked on October 31, 2026 against the Federal Register through October 30 and the current schedule, HTSUS 2026 Revision 22: the note 52 text and the general rates quoted here from Revision 20 are unchanged.

Does the 2026 Section 301 tariff apply to silicones?

Yes. Silicones in primary forms (3910.00.00) and organo-silicon compounds in 2931.90.90 from China (12.5%), India (10%) and the other investigated economies entered from July 24, 2026 pay it unless they are for use in a pharmaceutical application, or are Canadian or Mexican goods entered free of duty under the United States-Mexico-Canada Agreement (USMCA). U.S. note 52 to chapter 99 (HTSUS 2026 Revision 20, September 28, 2026) lists silicones in primary forms (3910.00.00) and organo-silicon compounds in 2931.90.90 only in its pharmaceutical-use exemption.

So, within the listed lines, the exemption turns on end use: the article must be classifiable in a listed provision and be for use in a pharmaceutical application. On the text of note 52(e), a China-origin lot of dimethicone, if it classifies in 3910.00.00 (an expectation to confirm with your broker, not a ruling), escapes the new forced-labor duty when it is for use in a pharmaceutical application, while the same lot entered for an industrial use does not.

Either way, the exemption lifts only the new duty: it leaves in place the general rate in the applicable subheading and the earlier China Section 301 duty of heading 9903.88.02, the applicable subheading’s duty + 25% (unless one of that heading’s listed exclusions applies). For a buyer comparing quotes, the forced-labor duty now depends on a fact about your own process, not only on the supplier’s price.

What changed on July 24, 2026?

USTR’s “Notice of Actions in Section 301 Investigations of Acts, Policies, and Practices of Various Economies” (91 FR 47318, FR Doc. 2026-15181, published July 28, 2026) applies its rates to goods entered for consumption, or withdrawn from warehouse for consumption, on or after 12:01 a.m. eastern time on July 24, 2026.

The China determination in the notice imposes “12.5 percent tariffs on products of China, except as provided in Annex I and Annex II, Part A”, and the India determination imposes 10 percent on products of India with the same exception. The rate follows the origin of the goods: 12.5% on a China-origin lot and 10% on an India-origin lot of the same fluid.

The new duty also arrived just as another layer expired. In HTSUS 2026 Revision 22, a compiler’s note to U.S. note 2(aa) says headings 9903.03.01 through 9903.03.11 “expired at the close of July 23, 2026”; under note 2(aa)(i), heading 9903.03.01 had imposed an additional duty on imports of “all products of any country”. A landed-cost model built before July 24 can therefore carry a layer that no longer applies, so rebuild it from the current schedule rather than adding the new rate to it.

The notice spared one group of lots: goods loaded onto a vessel at the port of loading and in transit on the final mode of transit before 12:01 a.m. eastern time on July 24, 2026, provided they were entered before 12:01 a.m. eastern time on July 28, 2026. That window has closed, so it has no bearing on a lot you price now.

The exemptions also changed between proposal and action. USTR determined to “exempt all of the products proposed for exemption in Annex A” to the June 5, 2026 Federal Register notice, “except the non-pharmaceutical applications of certain chemical products”. That sentence does not name the chemicals. The tariff schedule does, and for a silicone buyer the answer sits in note 52.

Which HTS lines carry silicone fluids, siloxanes and silanes?

Two lines in note 52 matter to a silicone buyer, and a third, outside it, shows where the exemption stops. The table gives them as they read in HTSUS 2026 Revision 20.

Two cyclic siloxanes have a ruling on point. U.S. Customs and Border Protection (CBP) ruling N302530 (February 7, 2019) classified octamethylcyclotetrasiloxane (D4, CAS 556-67-2) and decamethylcyclopentasiloxane (cyclopentasiloxane, D5, CAS 541-02-6) in subheading 2931.90.9010, and also listed heading 9903.88.03. The current schedule footnotes 2931.90.90 to heading 9903.88.04. Read against that schedule, the ruling puts D4 and D5 of the kind it describes on the 3.7% line, inside the same pharmaceutical-only exemption. D5’s formulation and restriction questions are a separate matter, covered in cyclopentasiloxane D5 safety and the EU restriction.

Dimethicone (CAS 9006-65-9) is a polydimethylsiloxane, and you may expect it to enter as a silicone in primary form under 3910.00.00. Without a ruling for your grade, that is an expectation, not a classification. A neat fluid and a formulated product that contains it are not always classified alike, so have the line for each grade of dimethicone you buy confirmed by your broker or a binding ruling before the duty goes into a landed-cost model.

One CAS number also spans many viscosity grades of dimethicone, as silicone oil by viscosity grade sets out, so name the grade as well as the line.

Silanes need the same care. Suffix 2931.90.90.10, “Organo-silicon compounds”, sits under 2931.90.90, which U.S. note 20(g) describes as “Other non-aromatic organo-inorganic compounds”, and the schedule names some organo-silicon compounds on their own lines: the chlorosilanes diphenyldichlorosilane and phenyltrichlorosilane in 2931.90.05, and N,N’-bis(trimethylsilyl) urea in 2931.90.70. Neither line is in any note 52 exemption list, so the pharmaceutical exemption cannot reach them.

The general rate moves with the line as well. Within 2931.90, 2931.90.90 (other non-aromatic compounds) is at 3.7%, while subheadings 2931.90.22, 2931.90.26, 2931.90.30 and 2931.90.60 carry a 6.5% general rate; note 52(e) lists 2931.90.22, 2931.90.30 and 2931.90.60 but not 2931.90.26. Which line, or which heading, a particular silane, or a silane in a solution or blend, falls in is a classification question for your broker or a ruling, not for the name on a quote.

What does the pharmaceutical carve-out settle, and what does it leave open?

Note 52(e) of HTSUS 2026 Revision 20 says the additional duties under headings 9903.05.20 through 9903.05.84 “shall not apply to articles that are for use in pharmaceutical applications” and classifiable in the listed provisions, which include 3910.00.00 and 2931.90.90. The exemption is provided in heading 9903.05.89.

It settles one point: within those lines the test is the article’s use, so the same silicone can be exempt from the new duty in one entry and subject to it in the next.

It leaves the proof open. Note 52(e) does not say how an importer shows CBP that a lot is for pharmaceutical use, and the exemption determination in the notice (91 FR 47318, July 28, 2026) does not say either. Nor does note 52(e) define “pharmaceutical applications”. Cosmetics and personal care are not mentioned in it, so where a personal-care product ends and a pharmaceutical application begins is a question for a binding ruling.

If a supplier quotes a lower duty-paid price on the strength of the exemption, ask who claimed it at entry, on what document, and whether your end use matches that claim. Until your broker or a binding ruling confirms the exemption for your lot, put the full duty into the comparison.

Which duties stack under note 52(a)?

Note 52(a) of HTSUS 2026 Revision 20 says products subject to the additional rates “shall also be subject to the general rates of duty imposed under subheadings in chapters 1 to 97”, and, except as provided in subdivisions (b) through (k), to “any additional duty provided for in this subchapter or in subchapter IV of chapter 99”.

For products of China and India, that puts the new rate (12.5% for China, 10% for India) on top of the 3% general rate for silicones in primary forms, or the 3.7% general rate for organo-silicon compounds classified in 2931.90.90, not in place of it.

For goods of China, the new duty is not the first Section 301 layer: 3910.00.00 is on the U.S. note 20(d) list for heading 9903.88.02, and 2931.90.90 on the note 20(g) list for heading 9903.88.04. Each heading reads “The duty provided in the applicable subheading + 25%”, subject to the exclusion headings it names. Both sit in subchapter III, where note 52 belongs, so note 52(a) keeps them in addition, and heading 9903.05.89 lifts only the new forced-labor duty, not these.

Other origins are set differently. The Presidential direction quoted in the notice (91 FR 47318, July 28, 2026) sets the Section 301 tariff on a product of the European Union or Taiwan whose MFN tariff is less than 10 percent “so that the sum of the MFN tariff and the section 301 tariff shall be 10 percent”; for a product of Japan, Korea or Switzerland whose MFN tariff is less than 12.5 percent, the sum “shall be 12.5 percent”.

The same direction lists India, Canada and Mexico among the economies at 10 percent, and its tier (iii) reads: “For goods of all other investigated economies, the Trade Representative shall impose a tariff rate of 12.5 percent.”

A lot from another origin is outside the new duty only if that origin is not one of the investigated economies or, for Canada and Mexico, if the goods are entered free of duty under the United States-Mexico-Canada Agreement (USMCA), as note 52(g) and (h) provide; otherwise the new duty applies at that origin’s rate.

Brazil-origin goods also carry a separate 2026 Section 301 duty: heading 9903.05.01 of HTSUS 2026 Revision 22 adds 25% on articles the product of Brazil, under U.S. note 50, except as headings 9903.05.02 through 9903.05.09 provide. Brazil is also one of the investigated economies of the forced-labor action (heading 9903.05.27), and the 25% duty has its own pharmaceutical-use exemption (heading 9903.05.06, U.S. note 50(a)(v)), whose list includes 3910.00.00 and 2931.90.90. Whether a new origin was investigated, and which chapter 99 headings apply to your entry, are questions for your broker.

An RFQ and landed-cost checklist for silicone buyers

Put these to every supplier quoting a China-origin or India-origin silicone lot, and the same questions to your broker:

1. Classification. Ask for the HTS line the lot will enter under, then confirm it with your customs broker or a binding ruling. For D4 and D5, check your lot against the merchandise described in CBP ruling N302530 before relying on it.

2. Country of origin. Get the origin of each lot in writing, since the notice applies its rates to “products of China” and “products of India” (91 FR 47318, July 28, 2026). If a lot was blended, repackaged or shipped through a third country, have your broker confirm its origin.

3. End use. State your end use on the RFQ. A quote that assumes the pharmaceutical exemption should say so, and name who will claim it and on what basis.

4. Duty lines. Ask for the general rate, the Section 301 rate and any other chapter 99 duty as separate lines, so you can see which one moves when origin or end use changes.

5. Incoterms. On DDP terms the supplier clears the lot for import, so it is the importer of record and the party that makes, or does not make, any pharmaceutical-use exemption claim at entry. Ask whether a DDP price assumes that claim, and who carries the duty if the claim is not allowed.

6. Entry date. Price on the date the lot will be entered, not the date it was quoted or loaded: the in-transit relief required entry before 12:01 a.m. eastern time on July 28, 2026.

Methodology: dates, rates and quoted text come from USTR’s notice at 91 FR 47318 (FR Doc. 2026-15181, published July 28, 2026); U.S. notes 20 and 52 to chapter 99 and the general rates in HTSUS 2026 Revision 20; and CBP ruling N302530 (February 7, 2019); no combined duty rate is calculated. This article is general information, not customs or legal advice; confirm the classification and duty of each lot with a licensed customs broker.

The HTSUS 2026 Revision 22 text cited here (U.S. notes 2(aa), 50 and 52; headings 9903.05.01, 9903.05.06 and 9903.05.27) was read on October 31, 2026.