Importers Seek Rate Certainty: Purolite Petitions to Add Styrene Copolymers to Superfund List

The Strategic Shift: Why Importers Want to Pay the Superfund Tax

As part of the ongoing implementation of the Superfund chemical excise taxes, reinstated by the Infrastructure Investment and Jobs Act (IIJA), the IRS has published a notice regarding a petition to modify the list of taxable substances. This notice, appearing in the Federal Register, signals more than a mere administrative update; it highlights a strategic maneuver by importers seeking to minimize their tax burden. The central issue revolves around Section 4672(a) of the Internal Revenue Code, which defines "taxable substances" subject to excise tax.

Purolite, an importer, has petitioned the IRS to add Styrene-DVB-EVB (>50%) to the list of taxable substances under Section 4672(a). This might seem counterintuitive – why would a company want to pay a tax? The answer lies in the way the IRS calculates the Superfund tax. If an imported substance contains taxable chemicals (as defined in Section 4661) but is not on the Section 4672(a) list, the IRS may impose a default tax based on 10% of the entry value, according to Section 4671(b)(2). This "tax on value" approach often results in a significantly higher tax bill than if the substance were listed and taxed based on the weight of its constituent chemicals. The tax rate is currently $9.93 per ton.

Therefore, Purolite's petition can be seen as a move towards rate certainty and potential cost reduction. By adding Styrene-DVB-EVB (>50%) to the list, the company aims to avoid the potentially exorbitant 10% tax on entry value and instead pay the tax based on the weight of the styrene content, as if the substance were manufactured in the U.S. This petition underscores the crucial importance of the Section 4672(a) list for importers dealing with chemical mixtures.

The Chemistry and the Calculation: Inside the Petition

As noted previously, Purolite's petition is a move towards rate certainty, with the current rate at $9.93 per ton. By adding Styrene-DVB-EVB (>50%) to the list under Section 4672(a), which provides the legal definitions and criteria for "taxable substances" subject to the Superfund excise tax upon import, the company aims to avoid the potentially exorbitant 10% tax on entry value and instead pay the tax based on the weight of the styrene content, as if the substance were manufactured in the U.S. This petition underscores the crucial importance of the Section 4672(a) list for importers dealing with chemical mixtures.

The petition itself contains specific technical information substantiating Purolite's request. The key elements include:

• Chemical Name: Poly(styrene-divinylbenzene-ethylvinylbenzene), with styrene content greater than 50% ((C8H8)x(C10H10)y(C10H12)z ; x=2.02x10^17, y=2.98x10^16, z=7.35x10^15 ). Also known as Styrene-DVB-EVB (Styrene > 50%).
• Proposed Classification Numbers:
  • HTSUS number: 3903.90.5000
  • Schedule B number: 3903.90.0000
• Tax Rate (calculated by Petitioner): $9.93 per ton.

The petition details that Styrene-DVB-EVB (Styrene > 50%) is a copolymer made of styrene, divinylbenzene (DVB), and ethylvinylbenzene (EVB) monomers. The predominant method of production involves the polymerization of these monomers. Styrene monomer is produced by the dehydrogenation of ethylbenzene using superheated steam over an iron(III) oxide catalyst. Ethylbenzene, in turn, is produced via a Friedel-Crafts reaction of benzene and ethylene.

Industrially, Styrene-DVB-EVB (Styrene > 50%) is primarily used for the production of ion exchange resins but can also be utilized as a column packing material in liquid chromatography, a separation medium in thin-layer chromatography, and as an adsorbent. Importantly, the petition emphasizes that taxable chemicals constitute 100% by weight of the materials used to produce the substance.

Industry Impact: Parallel Filings and Comment Deadlines

Following the petition for Styrene-DVB-EVB with styrene content greater than 50%, a second, parallel petition was filed requesting similar treatment for poly(styrene-divinylbenzene-ethylvinylbenzene) with styrene content less than 50%. This separate filing indicates a broader industry concern regarding the Superfund tax implications for these related polymers. The IRS has published a notice of filing for this second petition as well, initiating a similar process of review and public comment.

The stakes are high for importers of ion exchange resins. If the IRS grants these petitions and adds these substances to the list of taxable substances under Section 4672(a), importers will likely face a specific tonnage tax based on the benzene and ethylene used in production, rather than the significantly higher ad valorem tax (10% of appraised value) imposed under Section 4671(b)(2) when sufficient information to determine the weight-based rate is not furnished.

Interested parties are encouraged to submit written comments and requests for a public hearing regarding the proposed listing of Styrene-DVB-EVB (Styrene > 50%). The deadline for submissions is March 16, 2026. Comments should be submitted electronically via the Federal eRulemaking Portal at https://www.regulations.gov (referencing public docket number IRS–2025–0600) or mailed to the Internal Revenue Service, Attn: CC:PA:01:PR (Notice of Filing for Styrene-DVB-EVB (Styrene > 50%) ((C 8 H 8 ) x (C 10 H 10 ) y (C 10 H 12 ) z ; x=2.02x10 17 , y=2.98x10 16 , z=7.35x10 15 ), Room 5203, P.O. Box 7604, Ben Franklin Station, Washington, DC 20044.