OLIN Corp

We recorded an after-tax benefit of $39.9 million ($52.1 million pretax) to shareholders’ equity as of December 31, 2025, for our pension and other postretirement plans. This benefit primarily reflects a favorable performance on plan assets and a 60-basis point increase in the international defined benefit pension plans’ discount rate, partially offset by a 30-basis point decrease in the domestic pension plans’ discount rate during 2025.

In 2024, we recorded an after-tax benefit of $21.7 million ($29.7 million pretax) to shareholders’ equity as of December 31, 2024, for our pension and other postretirement plans. This benefit primarily reflected a 50-basis point increase in the domestic pension plans’ discount rate and a 20-basis point increase in the international defined benefit pension plans’ discount rate, partially offset by an unfavorable performance on plan assets during 2024.

In 2023, we recorded an after-tax charge of $13.2 million ($18.1 million pretax) to shareholders’ equity as of December 31, 2023, for our pension and other postretirement plans. This charge primarily reflected a 30-basis point decrease in the domestic pension plans’ discount rate and a 50-basis point decrease in the international defined benefit pension plans’ discount rate, partially offset by a favorable performance on plan assets during 2023.

Based on our plan assumptions and estimates, we will not be required to make any cash contributions to the domestic qualified defined benefit pension plan at least through 2026.

In connection with our international qualified defined benefit pension plans, we made cash contributions of $0.7 million, $1.3 million and $1.0 million in 2025, 2024 and 2023, respectively, and we anticipate less than $5 million of cash contributions to international qualified defined benefit pension plans in 2026.

At December 31, 2025, the projected benefit obligation of $2,024.8 million exceeded the market value of assets in our qualified defined benefit pension plans by $97.9 million, as calculated under Accounting Standards Codification (ASC) 715 “Compensation—Retirement Benefits.”

Components of net periodic benefit (income) costs were:

The service cost component of net periodic benefit (income) costs related to employees of the operating segments are allocated to the operating segments based on their respective estimated census data.

We have included additional information with respect our defined benefit pension plans and other postretirement benefit plans within Item 8—“Financial Statements and Supplementary Data,” Note 12, “Pension Plans,” and Note 13, “Postretirement Benefits,” of our notes to consolidated financial statements.