Exhibit 99.1

Stepan Reports Second Quarter 2025 Results

Northbrook, Illinois, July 30, 2025 -- Stepan Company (NYSE: SCL) today reported:

Second Quarter 2025 Highlights

First Half 2025 Highlights

“Quarterly earnings were up double digits driven by improved Polymer and Crop Productivity results as well as a lower effective tax rate. Polymer volume was up 7% as the North American Rigid, European Rigid and Phthalic Anhydride businesses all delivered volume growth. Within Surfactants, we also continued to experience double digit volume growth within the Agricultural and Oilfield end markets. This growth was offset by lower demand within the global commodity Consumer Products end markets," said Luis E. Rojo, President and Chief Executive Officer. "Second quarter adjusted EBITDA grew 8% and adjusted EBITDA is up 10% for the first half despite higher start-up expenses at our Pasadena site, the negative one-time events and a significant run up in Oleochemical raw material costs that we are planning to recover during the second half of the year. We remain encouraged by the growth within several of our key strategic end markets and we believe in our ability to recover raw material inflation gradually. Free cash flow was negative primarily due to

inventory builds. As previously communicated, our new alkoxylation site in Pasadena, Texas is now operational and will provide benefits in the second half of the year and going forward."

Financial Summary

Percentage Change in Net Sales

Net sales in the second quarter of 2025 increased 7% year-over-year. This increase was primarily driven by higher selling prices that were mainly attributable to the pass-through of higher raw material costs and more favorable product mix.

Segment Results

Consolidated adjusted EBITDA(2) increased $3.7 million, or 8%, in the quarter. This increase was primarily driven by Polymer sales volume growth of 7% and the non-recurrence of expenses associated with the external criminal social engineering fraud event in 2024. Surfactant adjusted EBITDA was down slightly due to a 1% decline in sales volume.

Income Taxes

The Company's effective tax rate was 19.2% in the first half of 2025 versus 36.1% in the first half of 2024. This decrease was primarily attributable to a favorable tax audit settlement in 2025 combined with the non-recurrence of an unfavorable GILTI-related event in the first half of 2024. These items were partially offset by the expected tax impact of certain cash repatriations to the United States.

Outlook

“Looking forward, we remain focused on accelerating our business strategies through enhanced operational excellence, improved product and customer mix and accelerated free cash flow generation. We believe our Surfactant business will experience continued growth in our key strategic end markets and that Polymer demand will continue improving as we get more market certainty and we execute our innovation and growth plans. Our Pasadena facility is now operational, and as we have previously communicated, this will enable us to deliver volume growth in our alkoxylation product line and Supply Chain savings during the second half of the year," said Luis E. Rojo, President and Chief Executive Officer. "We remain on track to close our asset sale in the Philippines during the fourth quarter and we will continue looking for opportunities to optimize our global footprint and asset base. Despite all the current market uncertainties, including the impact of tariffs, we remain optimistic that we will deliver full year Adjusted EBITDA and Adjusted Net Income growth and positive free cash flow in 2025.”

Notes

(1) Adjusted net income and adjusted earnings per share are non-GAAP measures which exclude deferred compensation income/expense, certain environmental remediation-related costs as well as other significant and infrequent/non-recurring items. See Table II for reconciliations of non-GAAP adjusted net income and adjusted earnings per diluted share.

(2) EBITDA and adjusted EBITDA are non-GAAP measures. See Table VI for calculations and GAAP reconciliations of EBITDA and adjusted EBITDA.

(3) Free cash flow is a non-GAAP measure and reflects cash generated from operations minus capital expenditures. Cash generated from operations was $11.2 million during the second quarter of 2025 and capital expenditures were $25.6 million.

Conference Call

Stepan Company will host a conference call to discuss its second quarter results at 9:00 a.m. ET (8:00 a.m. CT) on July 30, 2025. The call can be accessed by phone and webcast. To access the call by phone, please click on this Registration Link, complete the form and you will be provided with dial in details and a PIN. To avoid delays, we encourage

participants to dial into the conference call ten minutes ahead of the scheduled start time. The webcast can be accessed through the Investors/Conference Calls page at www.stepan.com. A webcast replay of the conference call will be available at the same location shortly after the call.

Supporting Slides

Slides supporting this press release will be made available at www.stepan.com through the Investors/Presentations page at approximately the same time as this press release is issued.

Corporate Profile

Stepan Company is a major manufacturer of specialty and intermediate chemicals used in a broad range of industries. Stepan is a leading merchant producer of surfactants, which are the key ingredients in consumer and industrial cleaning and disinfection compounds and in agricultural and oilfield solutions. The Company is also a leading supplier of polyurethane polyols used in the expanding thermal insulation market, and CASE (Coatings, Adhesives, Sealants, and Elastomers) industries.

Headquartered in Northbrook, Illinois, Stepan utilizes a network of modern production facilities located in North and South America, Europe and Asia.

The Company's common stock is traded on the New York Stock Exchange (NYSE) under the symbol SCL. For more information about Stepan Company please visit the Company online at www.stepan.com

More information about Stepan’s sustainability program can be found on the Sustainability page at www.stepan.com

Contact: Samuel S. Hinrichsen 847-446-7500

Certain information in this news release consists of forward-looking statements within the meaning of the Private Securities Litigation Reform Act of 1995, Section 27A of the Securities Act of 1933, as amended, and Section 21E of the Securities Exchange Act of 1934, as amended. These statements include statements about Stepan Company’s plans, objectives, strategies, financial performance and outlook, trends, the amount and timing of future cash distributions, prospects or future events and involve known and unknown risks that are difficult to predict. As a result, Stepan Company’s actual financial results, performance, achievements or prospects may differ materially from those expressed or implied by these forward-looking statements. In some cases, you can identify forward-looking statements by the use of words such as “may,” “could,” “expect,” “intend,” “plan,” “seek,” “anticipate,” “believe,” “estimate,” “guidance,” “predict,” “potential,” “continue,” “likely,” “will,” “would,” “should,” “illustrative” and variations of these terms and similar expressions, or the negative of these terms or similar expressions. Such forward-looking statements are necessarily based upon estimates and assumptions that, while considered reasonable by Stepan Company and its management based on their knowledge and understanding of the business and industry, are inherently uncertain. These statements are not guarantees of future performance, and stockholders should not place undue reliance on forward-looking statements.

There are a number of risks, uncertainties and other important factors, many of which are beyond Stepan Company's control, that could cause actual results to differ materially from the forward-looking statements contained in this news release. Such risks, uncertainties and other important factors include, among other factors, the risks, uncertainties and factors described in Stepan Company's Form 10-K, Form 10-Q and Form 8-K reports and exhibits to those reports, and include (but are not limited to) risks and uncertainties related to accidents, unplanned production shutdowns or disruptions in manufacturing facilities; reduced demand due to customer product reformulations or new technologies; our inability to successfully develop or introduce new products; compliance with laws; our ability to identify suitable acquisition candidates and successfully complete

and integrate acquisitions; global competition; volatility of raw material and energy costs and supply; disruptions in transportation or significant changes in transportation costs; downturns in certain industries and general economic downturns; international business risks, including currency exchange rate fluctuations, changes in global trade policies, including tariffs; legal restrictions and taxes; unfavorable resolution of litigation against us; maintaining and protecting intellectual property rights; our ability to access capital markets; global political, military, security or other instability; costs related to expansion or other capital projects; interruption or breaches of information technology systems; our ability to retain executive management and key personnel; and our debt covenants.

These forward-looking statements are made only as of the date hereof, and Stepan Company undertakes no obligation to update or revise these forward-looking statements, whether as a result of new information, future events or otherwise.

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Tables follow

Table I

STEPAN COMPANY

For the Three and Six Months Ended June 30, 2025 and 2024

(Unaudited – in 000's, except per share data)

Table II

Reconciliation of Non-GAAP Net Income and Earnings per Diluted Share*

* All amounts in this table are presented after-tax

The Company believes that certain non-GAAP measures, in conjunction with comparable GAAP measures, are useful for evaluating the Company’s operating performance and financial condition. The Company uses this non-GAAP information as an indicator of business performance and evaluates management’s effectiveness with specific reference to these indicators. Management believes that these non-GAAP financial measures provide useful supplemental information because they exclude non-operational items that affect comparability between years. These measures should be considered in addition to, not as substitutes for or superior to, measures of financial performance prepared in accordance with GAAP and may differ from similarly titled measures presented by other companies. The Company's Annual Report on Form 10-K for the year ended December 31, 2024 contains additional information regarding the use of non-GAAP financial measures.

Summary of Second Quarter 2025 Adjusted Net Income Items

Adjusted net income excludes non-operational deferred compensation income/expense, certain environmental remediation costs and other significant and infrequent or non-recurring items.

Table III

Reconciliation of Pre-Tax to After-Tax Adjustments

Management uses the non-GAAP adjusted net income metric to evaluate the Company's operating performance. Management excludes the items listed in the table below because they are non-operational items. The cumulative tax effect was calculated using the statutory tax rates for the jurisdictions in which the transactions occurred.

Table IV

Deferred Compensation Plans

The full effect of the deferred compensation plans on quarterly pre-tax income was $0.1 million of expense versus $0.4 million of income in the prior year. The quarter-end market prices of Company stock and the impact of deferred compensation on specific income statement line items is summarized below:

Effects of Foreign Currency Translation

The Company’s foreign subsidiaries transact business and report financial results in their respective local currencies. These results are translated into U.S. dollars at average foreign exchange rates appropriate for the reporting period. The table below presents the impact that foreign currency translation had on select income statement line items.

Corporate Expenses

Adjusted Corporate expenses decreased $3.3 million, or 18% for the quarter. This decrease was primarily due to the non-recurrence of expenses associated with a criminal social engineering scheme in 2024.

Table V

Stepan Company

Consolidated Balance Sheets

June 30, 2025 and December 31, 2024

Selected Balance Sheet Information

The Company’s total debt decreased by $1.3 million and cash decreased by $18.6 million versus March 31, 2025. The Company’s net debt level increased $17.3 million versus March 31, 2025 and the net debt ratio remained constant at 31% in the quarter (Net Debt and Net Debt Ratio are non-GAAP measures, reconciliations of which are shown in the table below). Management uses the non-GAAP net debt metric to show a more complete picture of the Company's overall liquidity, financial flexibility and leverage level.