SUPPLEMENTARY INFORMATION:

Request To Add Substance to the List

(a) Overview. A petition was filed pursuant to Rev. Proc. 2022-26 (2022-29 I.R.B. 90), as modified by Rev. Proc. 2023-20 (2023-15 I.R.B. 636), requesting that di-isononyl phthalate be added to the list of taxable substances under section 4672(a) of the Internal Revenue Code (List). The petition requesting the addition of di-isononyl phthalate to the List is based on weight and contains the information detailed in paragraph (b) of this document. The information is provided for public notice and comment pursuant to section 9 of Rev. Proc. 2022-26. The publication of petition information in this notice of filing is not a determination and does not constitute Treasury Department or ( printed page 20552) IRS confirmation of the accuracy of the information published.

(b) Petition Content.

(1) Substance name: Di-isononyl phthalate.

(2) Petitioner: Exxon Mobil Corporation, an exporter of di-isononyl phthalate.

(3) Proposed classification numbers:

(i) HTSUS number: 2917.33.00.50.

(ii) Schedule B number: 2917.33.00.50.

(iii) CAS number: 68515-48-0.

(4) Petition filing dates:

(i) Petition filing date for purposes of making a determination: May 1, 2025.

(ii) Petition filing date for purposes of section 11.02 of Rev. Proc. 2022-26, as modified by section 3 of Rev. Proc. 2023-20: July 1, 2022.

(5) Description from petition: Di-isononyl phthalate is a preferred choice PVC plasticizer for large-volume general use applications. It is suited for a variety of flexible PVC plastisol, extruded, and molded parts applications including coated fabrics, sheet products, tubing, gasketing, and wire insulation and jacketing. It is also used in wire and cable applications due to its good dielectric properties.

Di-isononyl phthalate is made from propylene and orthoxylene, which is an isomer of the taxable chemical xylene. Taxable chemicals constitute 62.90 percent by weight of the materials used to produce this substance.

(6) Process identified in petition as predominant method of production of substance: The predominant method of producing di-isononyl phthalate is via the esterification process. Most plasticizers are products of simple esterification reactions, which can be readily carried out in heated kettles with agitation and provision for water takeoff. While some plants produce plasticizers by such batch methods, newer, highly automated plants operate continuously, particularly if they emphasize a single product. Esterification catalysts ( e.g. sulfuric acid or p-toluenesulfonic acid) speed the reaction and are neutralized, washed, and then removed. The purity requirements for commercial plasticizers are very high; phthalate esters are usually colorless and are mostly odorless. The reaction usually requires an excess of alcohol, which is readily recycled. Analogous syntheses yield aliphatic dicarboxylic acid esters, benzoates, and trimellitates.

The hydrogen used for these reactions is not produced from steam-methane reforming; the source is from PO_X reactor, which feeds liquids, not methane. The PO_X process is an industrial process that converts hydrocarbons feeds into syngas (a combination of H₂ and CO gas). The hydrocarbon feed is in the liquid state; it does not feed gas (such as methane) or solids. The unit feeds a variety of liquid hydrocarbons such as paraffins, olefins, and aromatics in the C5-C20 range, obtained from the refinery pipestills and other chemicals units.

(7) Stoichiometric material consumption equation, based on process identified as predominant method of production:

5.12 × 0.94 C₃ H₆ [propylene] + 5.12 × 0.06 C₅ H₁₀ [amylene] + 2 CO [carbon monoxide] + 4 H₂ [hydrogen] + C₈ H₁₀ [orthoxylene] + 3 O₂ [oxygen] → C₂₆ H₄₂ O₄ [di-isononyl phthalate] + 4 H₂ O [water]

(8) Tax rate calculated by Petitioner, based on Petitioner's conversion factors for taxable chemicals used in production of substance:

(i) Tax rate: $7.11 per ton.

(ii) Conversion factors: 0.48 for propylene, 0.25 for xylene.

(9) Public docket number: IRS-2025-0046.

90 FR 20551