Significant Accounting Policies and Recent Accounting Developments (Policies)	12 Months Ended
Dec. 31, 2024
Accounting Policies [Abstract]
Basis of Presentation	Basis of Presentation The Financial Statements include the accounts and operations of the Company and its wholly owned, majority owned and controlled subsidiaries. Redeemable noncontrolling interests held in certain of the Company’s consolidated entities are reported as temporary equity in the consolidated balance sheets. The Company applies the equity method of accounting for investments in which it has an ownership interest of 20 percent to 50 percent or exercises significant influence over the related investee operations. All intercompany accounts and transactions are eliminated in consolidation. Certain amounts in prior periods have been reclassified to conform with the current period presentation. The Financial Statements are prepared in accordance with GAAP and the rules and regulations of the SEC. The preparation of consolidated financial statements in conformity with GAAP requires management to make estimates and assumptions that affect the reported amounts of assets, liabilities, revenues, expenses and disclosures of contingent assets and liabilities. Because of the inherent uncertainties in using estimates, actual results could differ from those expected as of the reporting date. Management believes that the estimates and assumptions used are reasonable.
Fiscal Year	The Company’s fiscal year end is the last day of the calendar year. For interim reporting periods, the Company uses the last Saturday of the fiscal quarter.
Discontinued Operations	Discontinued Operations As a result of the sale of its lumber and newsprint assets in August 2021, the Company presents the results for those operations and any associated impacts as discontinued operations. Unless otherwise stated, information in these notes to consolidated financial statements relates to continuing operations. See Note 4—Discontinued Operations for further information.
Subsequent Events	Subsequent Events In February and March 2025, the U.S. government imposed new tariffs on products imported from China, Canada and Mexico, which have and may result in additional retaliatory tariffs and other trade actions from these nations. Given the evolving nature of trade policies and the potential for further modifications, reductions or expansions of these tariffs, it remains uncertain how these actions will ultimately impact the Company. Beginning in January 2025, the Company reorganized its High Purity Cellulose operating segment as a result of changes in its internal operating model, significant developments in its Biomaterials strategy (see Note 2—Significant Accounting Policies and Recent Accounting Developments—Redeemable Noncontrolling Interest and Note 10—Debt and Finance Leases for information regarding the newly-formed subsidiary, BioNova, and important financing milestones reached) and a successful enterprise reporting system launch that significantly enhances the Company’s financial reporting capabilities. Specifically, the Company determined, in light of these new developments and capabilities, that the performance and outlook of the High Purity Cellulose business will be better managed as three separate businesses: Cellulose Specialties, Cellulose Commodities and a new Biomaterials business. No changes were made to the composition of the Paperboard and High-Yield Pulp operating segments. The Company will begin reporting based on this new segment structure in the Company’s Quarterly Report on Form 10-Q for the first quarter of fiscal 2025.
Translation of Foreign Currency	Translation of Foreign Currency Assets and liabilities of consolidated subsidiaries whose functional currency is other than the USD are translated into USD using currency exchange rates at the balance sheet date. Revenues and expenses are translated using the average currency exchange rates during the period. Foreign currency translation gains and losses are reported as a component of AOCI. Realized and unrealized gains and losses resulting from foreign currency transactions are included in operating results as incurred.
Cash and Cash Equivalents	Cash and Cash Equivalents Cash and cash equivalents include time deposits and other highly liquid investments with original maturities of three months or less.
Accounts Receivable and Allowance for Credit Loss	Accounts Receivable and Allowance for Credit Loss Trade accounts receivable are stated at the net amount expected to be collected. All customers are granted credit on a short-term basis and related credit risks are considered minimal. The Company maintains an allowance for expected credit losses resulting from the inability of its customers to make required payments. The Company’s allowance is based on historical patterns of accounts receivable collections and expected losses, including the consideration of general economic conditions. Outstanding accounts receivable balances are reviewed quarterly or more frequently when circumstances indicate a review is warranted, such as a significant change in the aging of the Company’s receivables or a customer’s financial condition. Write-offs are recorded when a customer receivable is deemed uncollectible and collection efforts have been exhausted.
Inventory	Inventory On January 1, 2024, the Company changed the method of valuation of its finished goods, work-in-process and raw materials inventories from first-in first-out to average cost. The Company believes the average cost method is preferable because it provides better matching of revenue and expense trends and better reflects periodic income from operations. This change was not retrospectively applied to prior periods presented, as the overall effect of the change is not deemed material to the Company’s consolidated financial statements. Manufacturing and maintenance supplies are valued at average cost. Inventory costs include material, labor and manufacturing overhead. The need for a provision for estimated losses from obsolete, excess or slow-moving inventories is reviewed periodically.
Property, Plant and Equipment	Property, Plant and Equipment Depreciation Property, plant and equipment are recorded at cost, including applicable freight, interest, construction and installation costs. High purity cellulose, paperboard and high-yield pulp production-related plant and equipment are depreciated using the units-of-production method. The total units of production used to calculate depreciation expense is determined by factoring annual production days, based on normal production conditions, by the economic useful life of the asset involved. Production-related assets under finance leases are depreciated using the straight-line method over the related lease term. The Company depreciates its non-production assets, including office, lab and transportation equipment, using the straight-line depreciation method over 3 to 25 years. Buildings and land improvements are depreciated using the straight-line method over 15 to 35 years and 5 to 30 years, respectively. Impairment Long-lived assets are reviewed for impairment when events or changes in circumstances indicate the carrying amount of an asset may not be recoverable. Property, plant and equipment are primarily grouped at the combined plant level, the lowest level for which independent cash flows are identifiable. Recoverability of assets that are held and used is measured by net undiscounted cash flows expected to be generated by the asset. If such assets are considered to be impaired, the impairment to be recognized is measured as the amount by which the carrying value exceeds the fair value of the assets, which is based on a discounted cash flow model. Assets to be disposed of are reported at the lower of the carrying amount or fair value, less cost to sell. In the third quarter of 2024, in conjunction with the indefinite suspension of Temiscaming High Purity Cellulose operations, the Company recorded a non-cash asset impairment of $25 million. See Note 3—Indefinite Suspension of Operations for further information. In the fourth quarter of 2023, in conjunction with the optimization and realignment of High Purity Cellulose assets, the Company recorded a non-cash impairment of $62 million related to certain assets at the Temiscaming and Jesup facilities. See Note 8—Property, Plant and Equipment, Net for further information.
Asset Retirement Obligations	Asset Retirement Obligations The Company is obligated to close out its operating sites’ landfills in accordance with certain legal requirements and records a liability for these obligations when the fair value can be reasonably estimated. In connection with these obligations, asset retirement liabilities are initially estimated and recorded based on discounted expected cash flows with a corresponding asset, capitalized as part of the related long-lived asset. Initial cost estimates are updated whenever events and circumstances indicate a new estimate is more appropriate. The asset is depreciated on a straight-line basis over the remaining useful life of the related asset. Accretion expense in connection with the discounted liability is also recognized over the same period. As of December 31, 2024 and 2023, the Company had accrued $13 million and $12 million, respectively, for asset retirement obligations in “other liabilities.” Related depreciation and accretion expenses are included in “other operating income (expense), net” in the consolidated statements of operations. During 2024, new obligations incurred were immaterial and no obligations were settled. Accretion expense was immaterial during the years ended December 31, 2024 and 2022 and was $1 million during 2023.
Capitalized Software	Capitalized Software The Company capitalizes certain costs in connection with obtaining software for internal use. These costs are generally amortized over 5 years, once the assets are ready for their intended use. As of December 31, 2024 and 2023, the Company had $50 million and $40 million, respectively, of capitalized software included in “other assets” in the consolidated balance sheets. Accumulated amortization was $22 million and $23 million at December 31, 2024 and 2023, respectively. Amortization expense for capitalized software is recorded in “cost of sales” and “selling, general and administrative expense” in the consolidated statements of operations and totaled $5 million, $4 million and $4 million for the years ended December 31, 2024, 2023 and 2022, respectively.
Maintenance Costs	Maintenance Costs The Company performs scheduled inspections and major repairs and maintenance of plant machinery and equipment at the Company’s manufacturing facilities during a full plant shutdown. Costs associated with these planned outage periods are referred to as shutdown costs and are incurred to ensure the long-term reliability and safety of the manufacturing operations. Major maintenance shutdown costs are accounted for by the deferral method, under which expenditures related to shutdown are capitalized when incurred and amortized to production cost on a straight-line basis over the period benefited or the period of time until the next scheduled major maintenance shutdown, which generally ranges from one year to 18 months. Shutdown costs are classified as operating activities in the consolidated statements of cash flows. As of December 31, 2024 and 2023, the Company had $14 million and $34 million, respectively, in deferred major maintenance shutdown costs recorded in “prepaid and other current assets” in the consolidated balance sheets.
Emission Allowances	Emissions Allowances The Company is subject to numerous international, federal and state-level rules, initiatives and proposals that address domestic and global climate issues, including those governing emissions. To comply with certain of these regulations and ordinances, the Company is allotted certain allowances or credits by governing authorities to offset the obligations created by the Company’s operations. There is no value assigned to the government-allotted emissions allowances in the consolidated balance sheets. Income or expense from the sale or purchase of emission allowances are recognized within “cost of sales” in the consolidated statements of operations. During the years ended December 31, 2024, 2023 and 2022, the Company recorded $10 million, $11 million and $12 million, respectively, of sales of excess emission allowances associated with its Tartas, France operations.
Research and Development Expense	Research and Development Expense R&D capabilities and activities are primarily focused on the High Purity Cellulose operating segment. These efforts are directed at further developing products and technologies, including improving the quality of cellulose fiber grades, improving manufacturing efficiency and environmental controls and reducing fossil fuel consumption. R&D expense was $5 million, $6 million and $7 million for the years ended December 31, 2024, 2023 and 2022, respectively.
Intangible Assets	Intangible Assets The Company has definite-life intangible assets that it acquired through a business combination. The definite-life intangible assets consist of customer lists and trade names and are amortized over their estimated useful lives for periods generally ranging from 8 to 15 years. The Company evaluates the recoverability of its definite-life intangible assets by comparing the net carrying value of the asset group to the undiscounted net cash flows expected to be generated from the use and eventual disposition of that asset group when events or changes in circumstances indicate that its carrying amount may not be recoverable. If the carrying amount of the asset group is not recoverable, the fair value of the asset group is measured, and, if the carrying amount exceeds the fair value, an impairment loss is recognized.
Equity Method Investments	Equity Method Investments Anomera, Inc. The Company is an investor in Anomera, a Canadian start-up corporation headquartered in Montreal, Quebec. Anomera manufactures CNC, a patented, biodegradable product, with uses in the cosmetics industry and various other industrial applications, including concrete, inks and pigments, polymer composites, coatings and adhesives industries. Anomera has a product development lab in Mississauga, Ontario and a production facility on the Company’s Temiscaming site that was constructed during 2021. In exchange for voting and non-voting interests, the Company has invested $12 million in Anomera through December 31, 2024. The Company and Anomera have entered into various service, leasing and supply agreements to support Anomera’s operations at the production facility. There are no financing agreements at Anomera for which the Company is liable. The Company has a 44 percent voting interest in Anomera and is able to exercise significant influence, but not control, as it does not have the ability to direct the decisions that most significantly impact its economic performance. The Company has evaluated this investment and has concluded it is not a variable interest entity. The Company accounts for this investment under the equity method of accounting and records its share of net earnings and losses on the investment in “equity in loss of equity method investment” in the consolidated statements of operations. During the years ended December 31, 2024, 2023 and 2022, the Company recorded losses of $2 million, $2 million and $3 million, respectively, on its equity investment in Anomera. LignoTech Florida LLC The Company holds a 45 percent interest in LTF, a joint venture accounted for under the equity method of accounting. Borregaard ASA, a public company in Norway traded on the Oslo Exchange, owns the remaining 55 percent interest. LTF purchases sulfite liquor from the Company’s Fernandina Beach, Florida plant and converts it to purified lignins and lignosulfonates, which are used in concrete, textile dyes, pesticides, batteries and other products. The Company recorded $11 million, $14 million and $20 million of lignin sales to the LTF joint venture during the years ended December 31, 2024, 2023 and 2022, respectively. The Company records its share of net earnings and losses on the investment in “other operating income (expense), net” in the consolidated statements of operations. During the years ended December 31, 2024 and 2022, the Company recorded income of $2 million and a loss of $3 million, respectively. During the year ended December 31, 2023, the Company recorded immaterial income on its investment in LTF. See Note 19—Other Operating Income (Expense), Net for further information. The Company is liable for certain financing agreements related to LTF. See Note 22—Commitments and Contingencies for further information.
Redeemable Noncontrolling Interest	Redeemable Noncontrolling Interest In November 2024, the Company and one of its subsidiaries entered into a shareholder agreement with SWEN, pursuant to which SWEN will fund up to €30 million in exchange for up to 222,222 preferred shares, representing an expected 20 percent total noncontrolling equity interest in BioNova. Of this commitment, €15 million was funded at the closing of the shareholder agreement in exchange for 111,111 preferred shares, which currently represents an equity interest in BioNova of approximately 14 percent. Subsequent funding is contingent on the achievement of project milestones expected during 2025. The preferred shares rank senior to holders of BioNova common stock with respect to dividend rights and rights on the distribution of assets on any voluntary or involuntary liquidation, dissolution or winding up of the affairs of BioNova. Dividend distributions are subject to certain conditions set forth in the shareholder agreement. The preferred shares also contain embedded redemption features, which would require the Company to transfer cash to SWEN upon an exercise of the call and the put options. The preferred shares are not deemed mandatorily redeemable and therefore have been classified as temporary equity. The call option may be exercised at the Company’s discretion as follows: •Between January 1, 2028 (inclusive) and December 31, 2031 (inclusive). •If not exercised during the above period, it becomes exercisable again between January 1, 2033 (inclusive) and December 31, 2034 (inclusive). The put option may be exercised at SWEN’s discretion as follows: •At any time in the presence of an event of default enabling BioNova’s lenders or their agent to request the acceleration of maturity of the related debt. •At any time in the event of a change of control. •Between January 1, 2032 (inclusive) and December 31, 2032 (inclusive), if the call option was not exercised. •Between January 1, 2035 (inclusive) and December 31, 2035 (inclusive), if the call option was still not exercised. Both options have an exercise price that ensures achievement of both an internal rate of return of 16 percent and a 2x multiple. The Company evaluated the call and put options embedded in the preferred shares and determined that the put option should be bifurcated and recognized separately at fair value, with subsequent changes in fair value recorded in earnings. See Note 13—Fair Value Measurements for further information on the fair value measurements of the put option. The value of SWEN’s redeemable noncontrolling interest is accreted to its estimated redemption value at each period end using the interest method. It is reflected in temporary equity at the current redemption value less the current carrying fair value amount of the bifurcated put option.
Revenue Recognition and Measurement	Revenue Recognition and Measurement Revenue is recognized when the performance obligations under a customer contract are satisfied. The Company’s customer contracts have a single performance obligation to transfer products. Accordingly, revenue is recognized when control has been transferred to the customer. Generally, control passes upon delivery to a location in accordance with the terms and conditions of the sale. Changes in customer contract terms and conditions, as well as the timing of orders and shipments, may impact the timing of revenue recognition. Revenue is measured as the amount of consideration the Company expects to receive in exchange for transferring its products and is generally based on contractual arrangements with customers or published indices. The Company sells its products both directly to customers and through distributors and agents, typically under agreements with payment terms less than 90 days. The Company elected to account for shipping and handling as activities to fulfill the promise to transfer the goods. As such, shipping and handling costs incurred are recorded in “cost of sales.” In addition, the Company has excluded from net sales any value-add, sales and other taxes collected concurrent with its revenue-producing activities. The nature of the Company’s contracts may give rise to variable consideration, which may be constrained, including sales volume-based rebates to customers. The Company estimates sales volumes based on anticipated purchases at the beginning of the period and records a rebate accrual for each purchase toward the requisite rebate volume. These estimated rebates are included in the transaction price as a reduction to net sales. The Company has certain contracts that contain performance obligations that are not significant in the context of the customer contract and has elected not to assess whether these promised goods or services are performance obligations. The Company did not have any material contract assets or contract liabilities as of December 31, 2024 or 2023.
Environmental Costs	Environmental Costs The Company has established liabilities to assess, remediate, maintain and monitor sites related to disposed operations from which no current or future benefit is discernible. These obligations are established based on projected spending over the next 20 years and require significant estimates to determine the proper amount at any point in time. The projected period, from 2025 through 2045, reflects the time during which potential future costs are both estimable and probable. As new information becomes available, these cost estimates are updated and the recorded liabilities are adjusted appropriately. Environmental liabilities are accounted for on an undiscounted basis and are reflected in “current environmental liabilities” and “non-current environmental liabilities” in the consolidated balance sheets.
Employee Benefit Plans	Employee Benefit Plans The determination of expense and funding requirements for the Company’s defined benefit pension and postretirement health care and life insurance plans are primarily based on several actuarial assumptions. The key assumptions include discount rate, return on assets, salary increases, health care cost trends, mortality rates and employee service lives. The components of periodic pension and postretirement costs, other than service costs, are presented separately, outside of operating income, in “components of pension and OPEB, excluding service costs” in the consolidated statements of operations. The service cost component of net periodic benefit cost is presented in “cost of sales” and “selling, general and administrative expense,” which correlates with the related employee compensation costs arising from services rendered during the period. Only the service cost component of the net periodic benefit cost is eligible for capitalization. Changes in the funded status of the Company’s plans are recorded through comprehensive income in the year in which the changes occur. Actuarial gains and losses, which occur when actual experience differs from actuarial assumptions, are reflected net of taxes in stockholders’ equity. If actuarial gains and losses exceed ten percent of the greater of plan assets or plan liabilities, the Company amortizes them over the average future service period.
Income Taxes	Income Taxes The Company uses the asset and liability method of accounting for income taxes. Under this method, deferred tax assets and liabilities are recognized for the estimated future tax consequences attributable to differences between the financial statement asset and liability carrying amounts and their respective tax bases, operating loss carryforwards and tax credit carryforwards. Deferred tax assets and liabilities are measured pursuant to tax laws using rates expected to apply to taxable income in the years in which the temporary differences are expected to be recovered or settled. The Company records a valuation allowance to reduce the carrying amounts of its DTAs if it is more likely than not that such DTAs will not be realized, with the exception of DTAs for suspended U.S. interest deductions, which do not have a full valuation allowance in accordance with specific AICPA guidance. See Note 20—Income Taxes for further information. The Company’s income tax returns are subject to audit by U.S. federal and state taxing authorities as well as foreign jurisdictions, including Canada and France. In evaluating the tax benefits associated with various tax filing positions, the Company records a tax benefit for an uncertain tax position if it is more likely than not to be realized upon ultimate settlement of the issue. The Company records a liability or an offset to the corresponding DTA for any uncertain tax position that does not meet this criterion. The Company adjusts its liabilities for unrecognized tax benefits in the period in which it is determined the issue is settled with the taxing authorities, the statute of limitations expires for the relevant taxing authority to examine the tax position or when new information becomes available. Interest expense and penalties, if applicable, related to unrecognized tax benefits are recorded in “income tax (expense) benefit” in the consolidated statements of operations.
Recent Accounting Developments	Recent Accounting Developments Accounting Standards Updates Implemented The Company adopted, for this 2024 Form 10-K, ASU 2023-07 “Segment Reporting (Topic 280): Improvements to Reportable Segment Disclosures,” which requires disclosures about significant segment expenses and other segment items on an interim and annual basis, as well as certain disclosures regarding the Company’s CODM. The Company applied the ASU retrospectively to all prior periods presented. See Note 21—Segment and Geographical Information for the new disclosures required by this ASU. The adoption of this ASU had no impact to the Company’s consolidated financial statements. Accounting Standards Updates Not Yet Implemented In November 2024, the FASB issued ASU 2024-03 “Income Statement—Reporting Comprehensive Income—Expense Disaggregation Disclosures (Subtopic 220-40): Disaggregation of Income Statement Expenses,” which requires additional information about specific expense categories in the notes to financial statements for both interim and annual reporting periods. This ASU is effective for public companies with annual reporting periods beginning after December 15, 2026, and interim reporting periods beginning after December 15, 2027, with early adoption permitted. The Company is currently evaluating the impact of this standard on its consolidated financial statements and related disclosures. In December 2023, the FASB issued ASU 2023-09 “Income Taxes (Topic 740): Improvements to Income Tax Disclosures,” which requires enhanced income tax disclosures, primarily through changes to the rate reconciliation and income taxes paid information. ASU 2023-09 should be applied on a prospective basis and is effective for annual periods beginning after December 15, 2024. Early adoption and retrospective application are permitted. The Company is currently evaluating the impact of this standard on its disclosures, with no impact expected to its consolidated financial statements. In August 2023, the FASB issued ASU 2023-05 “Business Combinations—Joint Venture Formations (Subtopic 805-60): Recognition and Initial Measurement,” which provides specific guidance on how a joint venture, upon formation, should recognize and initially measure assets contributed and liabilities assumed. This ASU should be applied on a prospective basis to all joint ventures with a formation date on or after January 1, 2025. Early adoption is permitted and joint ventures formed prior to the adoption date may elect to apply the new guidance retrospectively back to their original formation date. The Company is currently evaluating the impact of this standard on its consolidated financial statements and related disclosures.
Fair Value Measurements	Fair value is defined as the exchange price that would be received for an asset or paid to transfer a liability in the principal or most advantageous market for the asset or liability in an orderly transaction between market participants at the measurement date. A three-level hierarchy prioritizes the inputs used to measure fair value as follows: Level 1 — Quoted prices in active markets for identical assets or liabilities. Level 2 — Observable inputs other than quoted prices included in Level 1, such as quoted prices for similar assets and liabilities in active markets, quoted prices for identical or similar assets and liabilities in markets that are not active, or other inputs that are observable or can be corroborated by observable market data. Level 3 — Unobservable inputs that are supported by little or no market activity and that are significant to the fair value of the assets or liabilities. This includes certain pricing models, discounted cash flows methodologies and similar techniques that use significant unobservable inputs. The valuation methodologies used for measuring the fair value of these asset categories were as follows: Mutual funds and collective trusts — Net asset value in an observable market. Corporate bonds — Valued using pricing models that maximize the use of observable inputs for similar securities, including basing value on yields currently available on comparable securities of issuers with similar credit ratings. U.S. government securities — Valued using pricing models that maximize the use of observable inputs for similar securities. Common collective trust funds — Measured at net asset value per share, as a practical expedient for fair value, as provided by the plan trustee. The net asset value is calculated by determining the fair value of the fund’s underlying assets, deducting its liabilities, and dividing by the units outstanding as of the valuation date. These funds are not publicly traded; however, in most cases, the unit price calculation is based on observable market inputs of the funds’ underlying assets.
Financial Instruments	Financial Instruments The carrying amounts of the Company’s cash, receivables and payables approximate fair value due to the short-term nature of those instruments. The carrying amount of borrowings outstanding under the ABL Credit Facility, 2029 Term Loan and short-term factoring facility approximate fair value due to their variable interest rates.

Significant Accounting Policies and Recent Accounting Developments (Policies)

12 Months Ended

Dec. 31, 2024

The Financial Statements include the accounts and operations of the Company and its wholly owned, majority owned and controlled subsidiaries. Redeemable noncontrolling interests held in certain of the Company’s consolidated entities are reported as temporary equity in the consolidated balance sheets. The Company applies the equity method of accounting for investments in which it has an ownership interest of 20 percent to 50 percent or exercises significant influence over the related investee operations. All intercompany accounts and transactions are eliminated in consolidation. Certain amounts in prior periods have been reclassified to conform with the current period presentation.

The Financial Statements are prepared in accordance with GAAP and the rules and regulations of the SEC. The preparation of consolidated financial statements in conformity with GAAP requires management to make estimates and assumptions that affect the reported amounts of assets, liabilities, revenues, expenses and disclosures of contingent assets and liabilities. Because of the inherent uncertainties in using estimates, actual results could differ from those expected as of the reporting date. Management believes that the estimates and assumptions used are reasonable.

Fiscal Year

The Company’s fiscal year end is the last day of the calendar year. For interim reporting periods, the Company uses the last Saturday of the fiscal quarter.

Discontinued Operations

As a result of the sale of its lumber and newsprint assets in August 2021, the Company presents the results for those operations and any associated impacts as discontinued operations. Unless otherwise stated, information in these notes to consolidated financial statements relates to continuing operations. See Note 4—Discontinued Operations for further information.

Subsequent Events

In February and March 2025, the U.S. government imposed new tariffs on products imported from China, Canada and Mexico, which have and may result in additional retaliatory tariffs and other trade actions from these nations. Given the evolving nature of trade policies and the potential for further modifications, reductions or expansions of these tariffs, it remains uncertain how these actions will ultimately impact the Company.

Beginning in January 2025, the Company reorganized its High Purity Cellulose operating segment as a result of changes in its internal operating model, significant developments in its Biomaterials strategy (see Note 2—Significant Accounting Policies and Recent Accounting Developments—Redeemable Noncontrolling Interest and Note 10—Debt and Finance Leases for information regarding the newly-formed subsidiary, BioNova, and important financing milestones reached) and a successful enterprise reporting system launch that significantly enhances the Company’s financial reporting capabilities. Specifically, the Company determined, in light of these new developments and capabilities, that the performance and outlook of the High Purity Cellulose business will be better managed as three separate businesses: Cellulose Specialties, Cellulose Commodities and a new Biomaterials business. No changes were made to the composition of the Paperboard and High-Yield Pulp operating segments. The Company will begin reporting based on this new segment structure in the Company’s Quarterly Report on Form 10-Q for the first quarter of fiscal 2025.

Translation of Foreign Currency

Assets and liabilities of consolidated subsidiaries whose functional currency is other than the USD are translated into USD using currency exchange rates at the balance sheet date. Revenues and expenses are translated using the average currency exchange rates during the period. Foreign currency translation gains and losses are reported as a component of AOCI.

Realized and unrealized gains and losses resulting from foreign currency transactions are included in operating results as incurred.

Cash and Cash Equivalents

Cash and cash equivalents include time deposits and other highly liquid investments with original maturities of three months or less.

Accounts Receivable and Allowance for Credit Loss

Trade accounts receivable are stated at the net amount expected to be collected. All customers are granted credit on a short-term basis and related credit risks are considered minimal. The Company maintains an allowance for expected credit losses resulting from the inability of its customers to make required payments. The Company’s allowance is based on historical patterns of accounts receivable collections and expected losses, including the consideration of general economic conditions. Outstanding accounts receivable balances are reviewed quarterly or more frequently when circumstances indicate a review is warranted, such as a significant change in the aging of the Company’s receivables or a customer’s financial condition. Write-offs are recorded when a customer receivable is deemed uncollectible and collection efforts have been exhausted.

Inventory

On January 1, 2024, the Company changed the method of valuation of its finished goods, work-in-process and raw materials inventories from first-in first-out to average cost. The Company believes the average cost method is preferable because it provides better matching of revenue and expense trends and better reflects periodic income from operations. This change was not retrospectively applied to prior periods presented, as the overall effect of the change is not deemed material to the Company’s consolidated financial statements. Manufacturing and maintenance supplies are valued at average cost. Inventory costs include material, labor and manufacturing overhead. The need for a provision for estimated losses from obsolete, excess or slow-moving inventories is reviewed periodically.

Property, Plant and Equipment

Depreciation

Property, plant and equipment are recorded at cost, including applicable freight, interest, construction and installation costs. High purity cellulose, paperboard and high-yield pulp production-related plant and equipment are depreciated using the units-of-production method. The total units of production used to calculate depreciation expense is determined by factoring annual production days, based on normal production conditions, by the economic useful life of the asset involved. Production-related assets under finance leases are depreciated using the straight-line method over the related lease term. The Company depreciates its non-production assets, including office, lab and transportation equipment, using the straight-line depreciation method over 3 to 25 years. Buildings and land improvements are depreciated using the straight-line method over 15 to 35 years and 5 to 30 years, respectively.

Impairment

Long-lived assets are reviewed for impairment when events or changes in circumstances indicate the carrying amount of an asset may not be recoverable. Property, plant and equipment are primarily grouped at the combined plant level, the lowest level for which independent cash flows are identifiable. Recoverability of assets that are held and used is measured by net undiscounted cash flows expected to be generated by the asset. If such assets are considered to be impaired, the impairment to be recognized is measured as the amount by which the carrying value exceeds the fair value of the assets, which is based on a discounted cash flow model. Assets to be disposed of are reported at the lower of the carrying amount or fair value, less cost to sell.

In the third quarter of 2024, in conjunction with the indefinite suspension of Temiscaming High Purity Cellulose operations, the Company recorded a non-cash asset impairment of $25 million. See Note 3—Indefinite Suspension of Operations for further information.

In the fourth quarter of 2023, in conjunction with the optimization and realignment of High Purity Cellulose assets, the Company recorded a non-cash impairment of $62 million related to certain assets at the Temiscaming and Jesup facilities. See Note 8—Property, Plant and Equipment, Net for further information.

Asset Retirement Obligations

The Company is obligated to close out its operating sites’ landfills in accordance with certain legal requirements and records a liability for these obligations when the fair value can be reasonably estimated. In connection with these obligations, asset retirement liabilities are initially estimated and recorded based on discounted expected cash flows with a corresponding asset, capitalized as part of the related long-lived asset. Initial cost estimates are updated whenever events and circumstances indicate a new estimate is more appropriate. The asset is depreciated on a straight-line basis over the remaining useful life of the related asset. Accretion expense in connection with the discounted liability is also recognized over the same period. As of December 31, 2024 and 2023, the Company had accrued $13 million and $12 million, respectively, for asset retirement obligations in “other liabilities.” Related depreciation and accretion expenses are included in “other operating income (expense), net” in the consolidated statements of operations. During 2024, new obligations incurred were immaterial and no obligations were settled. Accretion expense was immaterial during the years ended December 31, 2024 and 2022 and was $1 million during 2023.

Capitalized Software

The Company capitalizes certain costs in connection with obtaining software for internal use. These costs are generally amortized over 5 years, once the assets are ready for their intended use. As of December 31, 2024 and 2023, the Company had $50 million and $40 million, respectively, of capitalized software included in “other assets” in the consolidated balance sheets. Accumulated amortization was $22 million and $23 million at December 31, 2024 and 2023, respectively. Amortization expense for capitalized software is recorded in “cost of sales” and “selling, general and administrative expense” in the consolidated statements of operations and totaled $5 million, $4 million and $4 million for the years ended December 31, 2024, 2023 and 2022, respectively.

Maintenance Costs

The Company performs scheduled inspections and major repairs and maintenance of plant machinery and equipment at the Company’s manufacturing facilities during a full plant shutdown. Costs associated with these planned outage periods are referred to as shutdown costs and are incurred to ensure the long-term reliability and safety of the manufacturing operations. Major maintenance shutdown costs are accounted for by the deferral method, under which expenditures related to shutdown are capitalized when incurred and amortized to production cost on a straight-line basis over the period benefited or the period of time until the next scheduled major maintenance shutdown, which generally ranges from one year to 18 months. Shutdown costs are classified as operating activities in the consolidated statements of cash flows. As of December 31, 2024 and 2023, the Company had $14 million and $34 million, respectively, in deferred major maintenance shutdown costs recorded in “prepaid and other current assets” in the consolidated balance sheets.

Emission Allowances

Emissions Allowances

The Company is subject to numerous international, federal and state-level rules, initiatives and proposals that address domestic and global climate issues, including those governing emissions. To comply with certain of these regulations and ordinances, the Company is allotted certain allowances or credits by governing authorities to offset the obligations created by the Company’s operations. There is no value assigned to the government-allotted emissions allowances in the consolidated balance sheets. Income or expense from the sale or purchase of emission allowances are recognized within “cost of sales” in the consolidated statements of operations. During the years ended December 31, 2024, 2023 and 2022, the Company recorded $10 million, $11 million and $12 million, respectively, of sales of excess emission allowances associated with its Tartas, France operations.

Research and Development Expense

R&D capabilities and activities are primarily focused on the High Purity Cellulose operating segment. These efforts are directed at further developing products and technologies, including improving the quality of cellulose fiber grades, improving manufacturing efficiency and environmental controls and reducing fossil fuel consumption. R&D expense was $5 million, $6 million and $7 million for the years ended December 31, 2024, 2023 and 2022, respectively.

Intangible Assets

The Company has definite-life intangible assets that it acquired through a business combination. The definite-life intangible assets consist of customer lists and trade names and are amortized over their estimated useful lives for periods generally ranging from 8 to 15 years. The Company evaluates the recoverability of its definite-life intangible assets by comparing the net carrying value of the asset group to the undiscounted net cash flows expected to be generated from the use and eventual disposition of that asset group when events or changes in circumstances indicate that its carrying amount may not be recoverable. If the carrying amount of the asset group is not recoverable, the fair value of the asset group is measured, and, if the carrying amount exceeds the fair value, an impairment loss is recognized.

Equity Method Investments

Anomera, Inc.

The Company is an investor in Anomera, a Canadian start-up corporation headquartered in Montreal, Quebec. Anomera manufactures CNC, a patented, biodegradable product, with uses in the cosmetics industry and various other industrial applications, including concrete, inks and pigments, polymer composites, coatings and adhesives industries. Anomera has a product development lab in Mississauga, Ontario and a production facility on the Company’s Temiscaming site that was constructed during 2021. In exchange for voting and non-voting interests, the Company has invested $12 million in Anomera through December 31, 2024. The Company and Anomera have entered into various service, leasing and supply agreements to support Anomera’s operations at the production facility. There are no financing agreements at Anomera for which the Company is liable.

The Company has a 44 percent voting interest in Anomera and is able to exercise significant influence, but not control, as it does not have the ability to direct the decisions that most significantly impact its economic performance. The Company has evaluated this investment and has concluded it is not a variable interest entity. The Company accounts for this investment under the equity method of accounting and records its share of net earnings and losses on the investment in “equity in loss of equity method investment” in the consolidated statements of operations. During the years ended December 31, 2024, 2023 and 2022, the Company recorded losses of $2 million, $2 million and $3 million, respectively, on its equity investment in Anomera.

LignoTech Florida LLC

The Company holds a 45 percent interest in LTF, a joint venture accounted for under the equity method of accounting. Borregaard ASA, a public company in Norway traded on the Oslo Exchange, owns the remaining 55 percent interest. LTF purchases sulfite liquor from the Company’s Fernandina Beach, Florida plant and converts it to purified lignins and lignosulfonates, which are used in concrete, textile dyes, pesticides, batteries and other products.

The Company recorded $11 million, $14 million and $20 million of lignin sales to the LTF joint venture during the years ended December 31, 2024, 2023 and 2022, respectively. The Company records its share of net earnings and losses on the investment in “other operating income (expense), net” in the consolidated statements of operations. During the years ended December 31, 2024 and 2022, the Company recorded income of $2 million and a loss of $3 million, respectively. During the year ended December 31, 2023, the Company recorded immaterial income on its investment in LTF. See Note 19—Other Operating Income (Expense), Net for further information.

The Company is liable for certain financing agreements related to LTF. See Note 22—Commitments and Contingencies for further information.

Redeemable Noncontrolling Interest

In November 2024, the Company and one of its subsidiaries entered into a shareholder agreement with SWEN, pursuant to which SWEN will fund up to €30 million in exchange for up to 222,222 preferred shares, representing an expected 20 percent total noncontrolling equity interest in BioNova. Of this commitment, €15 million was funded at the closing of the shareholder agreement in exchange for 111,111 preferred shares, which currently represents an equity interest in BioNova of approximately 14 percent. Subsequent funding is contingent on the achievement of project milestones expected during 2025.

The preferred shares rank senior to holders of BioNova common stock with respect to dividend rights and rights on the distribution of assets on any voluntary or involuntary liquidation, dissolution or winding up of the affairs of BioNova. Dividend distributions are subject to certain conditions set forth in the shareholder agreement. The preferred shares also contain embedded redemption features, which would require the Company to transfer cash to SWEN upon an exercise of the call and the put options. The preferred shares are not deemed mandatorily redeemable and therefore have been classified as temporary equity.

The call option may be exercised at the Company’s discretion as follows:

•Between January 1, 2028 (inclusive) and December 31, 2031 (inclusive).

•If not exercised during the above period, it becomes exercisable again between January 1, 2033 (inclusive) and December 31, 2034 (inclusive).

The put option may be exercised at SWEN’s discretion as follows:

•At any time in the presence of an event of default enabling BioNova’s lenders or their agent to request the acceleration of maturity of the related debt.

•At any time in the event of a change of control.

•Between January 1, 2032 (inclusive) and December 31, 2032 (inclusive), if the call option was not exercised.

•Between January 1, 2035 (inclusive) and December 31, 2035 (inclusive), if the call option was still not exercised.

Both options have an exercise price that ensures achievement of both an internal rate of return of 16 percent and a 2x multiple. The Company evaluated the call and put options embedded in the preferred shares and determined that the put option should be bifurcated and recognized separately at fair value, with subsequent changes in fair value recorded in earnings. See Note 13—Fair Value Measurements for further information on the fair value measurements of the put option.

The value of SWEN’s redeemable noncontrolling interest is accreted to its estimated redemption value at each period end using the interest method. It is reflected in temporary equity at the current redemption value less the current carrying fair value amount of the bifurcated put option.

Revenue Recognition and Measurement

Revenue is recognized when the performance obligations under a customer contract are satisfied. The Company’s customer contracts have a single performance obligation to transfer products. Accordingly, revenue is recognized when control has been transferred to the customer. Generally, control passes upon delivery to a location in accordance with the terms and conditions of the sale. Changes in customer contract terms and conditions, as well as the timing of orders and shipments, may impact the timing of revenue recognition.

Revenue is measured as the amount of consideration the Company expects to receive in exchange for transferring its products and is generally based on contractual arrangements with customers or published indices. The Company sells its products both directly to customers and through distributors and agents, typically under agreements with payment terms less than 90 days.

The Company elected to account for shipping and handling as activities to fulfill the promise to transfer the goods. As such, shipping and handling costs incurred are recorded in “cost of sales.” In addition, the Company has excluded from net sales any value-add, sales and other taxes collected concurrent with its revenue-producing activities.

The nature of the Company’s contracts may give rise to variable consideration, which may be constrained, including sales volume-based rebates to customers. The Company estimates sales volumes based on anticipated purchases at the beginning of the period and records a rebate accrual for each purchase toward the requisite rebate volume. These estimated rebates are included in the transaction price as a reduction to net sales.

The Company has certain contracts that contain performance obligations that are not significant in the context of the customer contract and has elected not to assess whether these promised goods or services are performance obligations.

The Company did not have any material contract assets or contract liabilities as of December 31, 2024 or 2023.

Environmental Costs

The Company has established liabilities to assess, remediate, maintain and monitor sites related to disposed operations from which no current or future benefit is discernible. These obligations are established based on projected spending over the next 20 years and require significant estimates to determine the proper amount at any point in time. The projected period, from 2025 through 2045, reflects the time during which potential future costs are both estimable and probable. As new information becomes available, these cost estimates are updated and the recorded liabilities are adjusted appropriately. Environmental liabilities are accounted for on an undiscounted basis and are reflected in “current environmental liabilities” and “non-current environmental liabilities” in the consolidated balance sheets.

Employee Benefit Plans

The determination of expense and funding requirements for the Company’s defined benefit pension and postretirement health care and life insurance plans are primarily based on several actuarial assumptions. The key assumptions include discount rate, return on assets, salary increases, health care cost trends, mortality rates and employee service lives.

The components of periodic pension and postretirement costs, other than service costs, are presented separately, outside of operating income, in “components of pension and OPEB, excluding service costs” in the consolidated statements of operations. The service cost component of net periodic benefit cost is presented in “cost of sales” and “selling, general and administrative expense,” which correlates with the related employee compensation costs arising from services rendered during the period. Only the service cost component of the net periodic benefit cost is eligible for capitalization.

Changes in the funded status of the Company’s plans are recorded through comprehensive income in the year in which the changes occur. Actuarial gains and losses, which occur when actual experience differs from actuarial assumptions, are reflected net of taxes in stockholders’ equity. If actuarial gains and losses exceed ten percent of the greater of plan assets or plan liabilities, the Company amortizes them over the average future service period.

Income Taxes

The Company uses the asset and liability method of accounting for income taxes. Under this method, deferred tax assets and liabilities are recognized for the estimated future tax consequences attributable to differences between the financial statement asset and liability carrying amounts and their respective tax bases, operating loss carryforwards and tax credit carryforwards. Deferred tax assets and liabilities are measured pursuant to tax laws using rates expected to apply to taxable income in the years in which the temporary differences are expected to be recovered or settled. The Company records a valuation allowance to reduce the carrying amounts of its DTAs if it is more likely than not that such DTAs will not be realized, with the exception of DTAs for suspended U.S. interest deductions, which do not have a full valuation allowance in accordance with specific AICPA guidance. See Note 20—Income Taxes for further information.

The Company’s income tax returns are subject to audit by U.S. federal and state taxing authorities as well as foreign jurisdictions, including Canada and France. In evaluating the tax benefits associated with various tax filing positions, the Company records a tax benefit for an uncertain tax position if it is more likely than not to be realized upon ultimate settlement of the issue. The Company records a liability or an offset to the corresponding DTA for any uncertain tax position that does not meet this criterion. The Company adjusts its liabilities for unrecognized tax benefits in the period in which it is determined the issue is settled with the taxing authorities, the statute of limitations expires for the relevant taxing authority to examine the tax position or when new information becomes available. Interest expense and penalties, if applicable, related to unrecognized tax benefits are recorded in “income tax (expense) benefit” in the consolidated statements of operations.

Recent Accounting Developments

Accounting Standards Updates Implemented

The Company adopted, for this 2024 Form 10-K, ASU 2023-07 “Segment Reporting (Topic 280): Improvements to Reportable Segment Disclosures,” which requires disclosures about significant segment expenses and other segment items on an interim and annual basis, as well as certain disclosures regarding the Company’s CODM. The Company applied the ASU retrospectively to all prior periods presented. See Note 21—Segment and Geographical Information for the new disclosures required by this ASU. The adoption of this ASU had no impact to the Company’s consolidated financial statements.

Accounting Standards Updates Not Yet Implemented

In November 2024, the FASB issued ASU 2024-03 “Income Statement—Reporting Comprehensive Income—Expense Disaggregation Disclosures (Subtopic 220-40): Disaggregation of Income Statement Expenses,” which requires additional information about specific expense categories in the notes to financial statements for both interim and annual reporting periods. This ASU is effective for public companies with annual reporting periods beginning after December 15, 2026, and interim reporting periods beginning after December 15, 2027, with early adoption permitted. The Company is currently evaluating the impact of this standard on its consolidated financial statements and related disclosures.

In December 2023, the FASB issued ASU 2023-09 “Income Taxes (Topic 740): Improvements to Income Tax Disclosures,” which requires enhanced income tax disclosures, primarily through changes to the rate reconciliation and income taxes paid information. ASU 2023-09 should be applied on a prospective basis and is effective for annual periods beginning after December 15, 2024. Early adoption and retrospective application are permitted. The Company is currently evaluating the impact of this standard on its disclosures, with no impact expected to its consolidated financial statements.

In August 2023, the FASB issued ASU 2023-05 “Business Combinations—Joint Venture Formations (Subtopic 805-60): Recognition and Initial Measurement,” which provides specific guidance on how a joint venture, upon formation, should recognize and initially measure assets contributed and liabilities assumed. This ASU should be applied on a prospective basis to all joint ventures with a formation date on or after January 1, 2025. Early adoption is permitted and joint ventures formed prior to the adoption date may elect to apply the new guidance retrospectively back to their original formation date. The Company is currently evaluating the impact of this standard on its consolidated financial statements and related disclosures.

Fair Value Measurements

Fair value is defined as the exchange price that would be received for an asset or paid to transfer a liability in the principal or most advantageous market for the asset or liability in an orderly transaction between market participants at the measurement date. A three-level hierarchy prioritizes the inputs used to measure fair value as follows:

Level 1 — Quoted prices in active markets for identical assets or liabilities.

Level 2 — Observable inputs other than quoted prices included in Level 1, such as quoted prices for similar assets and liabilities in active markets, quoted prices for identical or similar assets and liabilities in markets that are not active, or other inputs that are observable or can be corroborated by observable market data.

Level 3 — Unobservable inputs that are supported by little or no market activity and that are significant to the fair value of the assets or liabilities. This includes certain pricing models, discounted cash flows methodologies and similar techniques that use significant unobservable inputs.

The valuation methodologies used for measuring the fair value of these asset categories were as follows:

Mutual funds and collective trusts — Net asset value in an observable market.

Corporate bonds — Valued using pricing models that maximize the use of observable inputs for similar securities, including basing value on yields currently available on comparable securities of issuers with similar credit ratings.

U.S. government securities — Valued using pricing models that maximize the use of observable inputs for similar securities.

Common collective trust funds — Measured at net asset value per share, as a practical expedient for fair value, as provided by the plan trustee. The net asset value is calculated by determining the fair value of the fund’s underlying assets, deducting its liabilities, and dividing by the units outstanding as of the valuation date. These funds are not publicly traded; however, in most cases, the unit price calculation is based on observable market inputs of the funds’ underlying assets.

Financial Instruments

The carrying amounts of the Company’s cash, receivables and payables approximate fair value due to the short-term nature of those instruments. The carrying amount of borrowings outstanding under the ABL Credit Facility, 2029 Term Loan and short-term factoring facility approximate fair value due to their variable interest rates.