ADVANSIX APPOINTS PATRICK C. DAY AS SENIOR VICE PRESIDENT AND CHIEF FINANCIAL OFFICER (Form 8-K)

ADVANSIX APPOINTS PATRICK C. DAY AS SENIOR VICE PRESIDENT AND CHIEF FINANCIAL OFFICER

Parsippany, N.J., April 13, 2026 - AdvanSix (NYSE: ASIX), an integrated chemistry company serving diverse end markets, today announced the appointment of Patrick C. Day as its Senior Vice President and Chief Financial Officer, effective April 27, 2026. Pat will report directly to Erin Kane, President and Chief Executive Officer of AdvanSix, and will be a member of the Company's executive leadership team.

"Pat is a proven finance leader with the experience needed to help guide AdvanSix through our next stage of growth and opportunity," said Erin Kane, President and Chief Executive Officer of AdvanSix. "Pat's appointment reflects our commitment to building strong leadership and financial capabilities to drive long-term value creation for our shareholders. He brings the right balance of operational and financial discipline, strategic insight and collaborative leadership to navigate the opportunities ahead."

Day's extensive experience includes enabling enterprise strategic growth, financial operational discipline and value creation in publicly traded, global industrial and chemical companies. He most recently served as Vice President of Financial Planning and Analysis and Investor Relations at FMC Corporation, where he led enterprise-wide FP&A, strategic planning, forecasting, earnings analysis and investor communications. His background also includes senior global finance leadership roles at FMC, with earlier experience in Deloitte Consulting's Finance Transformation practice and various finance roles with United Technologies Corporation. Pat holds a bachelor's degree in finance from Elizabethtown College and a master's degree in accounting and tax from the University of Connecticut.

"I am excited to join AdvanSix at a time when the company has a clear strategy and roadmap, strong momentum and a compelling opportunity ahead," said Pat Day. "What drew me to AdvanSix is the combination of its portfolio of essential chemistries that

power everyday life, a safety-focused culture intent on delivering impact and a leadership team with a clear emphasis on long-term value creation. AdvanSix is well positioned for the future, and I am excited to partner with the team to support disciplined performance and drive long-term growth."

Day replaces Christopher Gramm, who has been serving as Interim Chief Financial Officer during the Company's search for a permanent Chief Financial Officer. Chris will continue to serve as Vice President of Corporate Finance and Strategic Financial Planning & Analysis for AdvanSix.

About AdvanSix

AdvanSix is an integrated chemistry company that produces essential materials for our customers across diverse end markets. Our value chain of our five U.S.-based manufacturing facilities plays a critical role in global supply chains and enables us to innovate and deliver essential products for our customers across building and construction, fertilizers, agrochemicals, plastics, solvents, packaging, paints, coatings, adhesives, electronics and other end markets. Guided by our core values of Safety, Integrity, Accountability and Respect, AdvanSix strives to deliver best-in-class customer experiences and differentiated products in the industries of nylon solutions, plant nutrients, and chemical intermediates. More information on AdvanSix can be found at http://www.advansix.com.