AdvanSix Inc. (ASIX) Business

Item 1. Business

In this Annual Report on Form 10-K, unless the context otherwise dictates, “AdvanSix,” the “Company,” “we,” “us” or “our” means AdvanSix Inc. and its consolidated subsidiaries.

Corporate History

On October 1, 2016, Honeywell International Inc. (“Honeywell”) completed the separation of AdvanSix. The separation was completed by Honeywell distributing (the "Distribution") all of the then outstanding shares of common stock of AdvanSix on October 1, 2016 (the “Distribution Date”) through a dividend in kind of AdvanSix common stock, par value $0.01 per share, to holders of Honeywell common stock as of the close of business on the record date of September 16, 2016 who held their shares through the Distribution Date.

Description of Business

AdvanSix Inc. is an integrated chemistry company that produces essential materials for 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. Our key product lines are as follows:

•Nylon Solutions

◦Nylon – We sell our Nylon 6 resin globally, primarily under the Aegis® brand name. Nylon 6 is a polymer resin which is a synthetic material used by our customers to produce fibers, filaments, engineered plastics and films that, in turn, are used in such end-products as carpets, automotive and electric components, sports apparel, food packaging and other industrial applications.

◦Caprolactam – Caprolactam is the key monomer used in the production of Nylon 6 resin. We internally polymerize caprolactam into Aegis® Nylon 6 Resin, and we also market and sell the caprolactam that is not consumed internally to customers who use it to manufacture polymer resins to produce fibers, compounds and other nylon products. Our Hopewell manufacturing facility is one of the world’s largest single-site producers of caprolactam as of December 31, 2025.

•Plant Nutrients – Our ammonium sulfate is used by customers as a fertilizer containing nitrogen and sulfur, two key plant nutrients. Ammonium sulfate fertilizer is derived from the integrated operations at the Hopewell manufacturing facility. Because of our Hopewell facility’s size, scale and technology design, we are the world’s largest single-site producer of ammonium sulfate fertilizer as of December 31, 2025. We market and sell ammonium sulfate primarily to North American and South American distributors, farm cooperatives and retailers to fertilize crops. We also manufacture sulfuric acid, ammonia and carbon dioxide as part of our integrated operations at Hopewell and occasionally sell any excess material not consumed internally to customers externally.

•Chemical Intermediates – We manufacture, market and sell a number of chemical intermediate products that are derived from the manufacturing processes within our integrated supply chain. Most significant is acetone which is used by our customers in the production of solvents, paints, coatings, adhesives, resins and herbicides. Other intermediate chemicals that we manufacture, market and sell include phenol, alpha-methylstyrene ("AMS"), cyclohexanone, oximes, cyclohexanol, and alkyl-amines and specialty amines. Additional end-products for intermediates include automotive components, and water treatment and pharmaceutical intermediates.

Each of these product lines represented the following approximate percentage of total sales:

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* In 2024, the Company transferred certain products between its Chemical Intermediates product line and its Plant Nutrients product line to align more closely with its current sales structure. Historical information was reclassified to reflect these changes for all periods presented in the Consolidated Financial Statements. Total revenue amounts were not impacted for either period.

The following charts illustrate the distribution of our sales by product line and by region, measured by the destination of each sale, for the year ended December 31, 2025:

For information concerning revenues and assets by geographic region, see “Note 3. Revenue” to our Consolidated Financial Statements included in Item 8 of this Form 10-K, which is incorporated herein by reference.

Our manufacturing process is vertically integrated. We use cumene, a chemical compound produced from benzene and propylene, to manufacture phenol, acetone and AMS at our Frankford, Pennsylvania plant. The majority of the phenol we manufacture is further processed at our Hopewell facility through an integrated series of unit operations, which also consume natural gas and sulfur, to primarily produce caprolactam and ammonium sulfate. In 2025, approximately 53% of the caprolactam we produced at our facility in Hopewell, Virginia was shipped to our facility in Chesterfield, Virginia where it was polymerized into Aegis® Nylon 6 resin. Manufacturing for our U.S. Amines portfolio occurs at our two facilities located in Bucks, Alabama and Portsmouth, Virginia. The below chart shows the Company's integrated value chain:

Our integrated manufacturing process, our scale and the quantity and range of our products make us one of the most reliable and efficient manufacturers in our industry. We consistently focus on and invest in improving production yields from our various manufacturing processes to build on our leading global cost advantage. Our logistics infrastructure enables a reliable intra-plant supply chain and consistent and timely delivery to our customers. In addition, we strive to understand the product applications and end markets into which our products are sold, which helps us upgrade the quality, chemical properties and packaging of our products to enable us to attract price premiums and greater demand.

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AdvanSix serves approximately 375 customers annually, primarily in the United States, with global capabilities, spanning a wide variety of industries. For the years ended December 31, 2025, 2024 and 2023, we had sales of $1,522 million, $1,518 million and $1,534 million with net income of $49 million, $44 million and $55 million, respectively. For the years ended December 31, 2025, 2024 and 2023, our international sales were $212 million, $213 million and $284 million, respectively.

AdvanSix is a single operating segment and a single reportable segment, operating through five U.S.-based manufacturing sites located in Frankford, Pennsylvania, Hopewell, Chesterfield and Portsmouth, Virginia and Bucks, Alabama. The Company's headquarters is located in Parsippany, New Jersey.

Competitive Strengths

Low-Cost Position Driven by Integrated Manufacturing Footprint, Large Scale, Favorable Geographical Location, and High Utilization Rates. Our vertically integrated manufacturing facilities, scale, access to lower cost raw materials, and high plant utilization rates help us maintain our position as the world's lowest cost producer of caprolactam. First, we are vertically integrated into several key feedstock materials necessary to produce caprolactam, particularly phenol, ammonia and oleum/sulfuric acid, which we believe is a unique advantage in our industry. Our integration allows us to remain flexible, while optimizing sales from our diverse portfolio of products. Second, we operate one of the world’s largest single-site caprolactam and ammonium sulfate production facilities, which is a competitive advantage in our globally fragmented industry. Our scale provides operating and purchasing leverage and the opportunity to achieve stronger business performance than our competitors in several ways. Most fundamentally, it enables us to spread fixed and overhead costs across more pounds of production, thereby enabling us to produce caprolactam at a lower per pound cost than our competitors. Third, the location of our manufacturing operations in the United States affords us access to low-cost natural gas, which is a key raw material needed to manufacture the ammonia used in the production of caprolactam and ammonium sulfate as well as the source of energy for our manufacturing operations. By contrast, a significant number of our competitors are in geographic locations where energy prices are substantially higher. Our footprint also provides access to a number of higher value end markets across our product lines. Finally, our long-term customer relationships and contracts enable us to maintain high plant utilization rates through the cycle, which, along with our size and scale, serves to retain and attract customers who prioritize security of supply.

Diverse Revenue Sources from the Sale of Ammonium Sulfate Fertilizer, Acetone and Other Chemical Intermediates. Due to our specific chemical manufacturing processes, vertical integration and scale, we produce ammonium sulfate fertilizer, acetone and a wide range of other chemical intermediates that enable us to diversify our revenue sources. Most significantly, for every pound of caprolactam produced, we produce approximately four pounds of ammonium sulfate, a fertilizer used by farmers around the world. For many decades, we have employed agronomists to educate growers and retailers in the Americas on the yield value of using ammonium sulfate fertilizer on key crops including corn, wheat, coffee, sugar, cotton and rice. We have been executing a program to educate growers and retailers on the yield benefit of ammonium sulfate fertilizer on soybeans and have generated on-farm research results that support this crop management practice. Traditionally grown as a less resource intensive alternative to corn, we see soybeans as a potential growth area for nitrogen and sulfur fertilizers as researchers continue to better understand the yield increases that growers can realize by fertilizing soybean crops with these two nutrients. We have also diversified and optimized our ammonium sulfate-based offerings to include a spray-grade adjuvant to support crop protection, as well as other specialty fertilizers and products for industrial use. Sales of plant nutrients' products in 2025 were $564 million and represented 37% of our total sales. We are among the most significant suppliers of acetone to a variety of end markets in North America. Sales of acetone in 2025 were approximately $222 million and represented 15% of our total sales. For AdvanSix, acetone is a key product line with a perform and optimize strategy to meet customer needs while driving favorable sales and profitability mix. In addition to ammonium sulfate and acetone, other products from our manufacturing process include high-purity phenol, AMS, cyclohexanone, oximes, cyclohexanol, sulfuric acid, ammonia and carbon dioxide. The diversity of our sales portfolio helps to mitigate, to some extent, the cyclicality in our end markets. We believe we are aligned to several favorable macro trends that are supporting growth across the portfolio including urbanization and aging infrastructure, digital transformation, global food production and resource scarcity, and a shift to green and performance chemicals. In addition, our U.S. Amines portfolio enables further diversification into agrochemical intermediates, water treatment and pharmaceuticals.

U.S. Value Chain Providing Consistency and Reliability for Domestic Customer Base. With all of our manufacturing located in the U.S., 86% of our sales in the U.S., and primarily procuring our key raw materials domestically, our integrated value chain provides consistency and reliability for our predominantly domestic customer base. Our cost position, business model, and sales and marketing capabilities, however, enable us to compete globally where nylon resin, caprolactam, ammonium sulfate and chemical intermediates are consumed. Our freight and logistics capabilities and terminal locations position us well to serve global markets, including the dock and loading facility at our Hopewell facility which serves ocean-going dry-bulk freight vessels. Our global reach enables us to arbitrage geographic price variations to ensure we are receiving the highest value for our products.

Technical Know-How, Customer Intimacy and Application Development Capabilities. Intimate knowledge of our customers and end market applications, combined with our technical know-how, enables us to develop differentiated, higher quality products that are

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often valued higher by customers compared to commodity products. Our technology talent consists of scientists and engineers with degrees in polymer and chemical synthesis, catalysis and chemical engineering, who work on driving unique offerings and developing new products across our diverse portfolio. Our agronomist provides the latest scientific information on the importance of sulfur nutrition for crops and how to optimize the benefits of ammonium sulfate fertilizer to our global customers through a variety of channels including webinars, technical training sessions for retailers and direct grower meetings. We also have a strategic focus around placing our various chemistry platforms into high-value applications. This diversification of end market exposure supports our sales and margin performance in spaces such as electronics, alkyd-based paints and pharmaceutical and other industrial applications.

Business Strategies

Operational Excellence and Improving Through-Cycle Profitability. Through our vertical integration, size, access to low-cost raw materials, and high utilization rates, we seek to build on our low-cost leadership position and expand operating margins by reducing our Nylon 6 resin, caprolactam, ammonium sulfate and other chemical intermediate production costs. While our global low-cost position supports our ability to operate at disproportionately higher utilization rates relative to our industries and to meet demand where it exists through a cycle, our goal of generating higher lows and higher highs requires us to drive productivity, optimize our regional and product sales mix, and continue to promote the value proposition of our differentiated offerings. Operational excellence is a key enabler to our overall performance, and we take all the learnings for sustained continuous improvement with rigor and discipline. There is a meaningful annual opportunity of sustainably running at our targeted production rates. Our focus on operational excellence and ongoing productivity improvements concentrate on the following:

•Increasing production volume through asset reliability, flexibility and capacity;

•Investing in digital transformation and process automation to optimize and improve operational efficiency;

•Executing planned plant turnarounds and prioritizing replacement maintenance capital investments to mitigate risk and support safe, stable and sustainable operations;

•Investing in intermediate chemical buffer storage capacity to mitigate the unfavorable impact of routine maintenance and unplanned interruptions;

•Energy and direct material initiatives aimed at increasing plant productivity and lowering costs; and

•Procurement processes, competitive bidding and supplier diversification to reduce raw material and indirect costs.

Enhancing Portfolio Resiliency. Our diverse portfolio serves us well particularly during times of uncertainty. Supplementing our exposure to diverse end-use applications, we have enhanced our sales mix through our differentiated product portfolio. Over the past several years, we have invested in capabilities to strengthen our innovation, increase the value of our product portfolio and meet customer specifications in certain high value industries including high-purity applications, high-value intermediates and differentiated nylon. We have had successes across the portfolio including our oximes-based EZ-Blox® anti-skinning agent used in paints and coatings, and our Nadone® cyclohexanone product line, which is a solvent used in various high-value applications. Growing off a small base, we have also seen commercial success with our Nylon-based wire and cable offerings as well as copolymer Nylon 6/66 resin, which are used in engineered plastics for the automotive industry, films for food packaging, as well as other higher value applications. In addition, as a result of recent efforts and enhancements in crystallizer technology and operations, we are now producing a high-quality granular grade ammonium sulfate at greater conversion levels to meet the growing demand of our customers. These efforts are being supplemented by our multi-year SUSTAIN (Sustainable U.S. Sulfate To Accelerate Increased Nutrition) program's planned expansion in granular ammonium sulfate production. We are focused on working with customers to solve their needs with respect to sustainability and have commercialized our 100% Post-Industrial and Post-Consumer Recycled nylon. Our technology team works with existing and potential customers to understand end-use applications, build application development capabilities and protect the value proposition of our new products.

Strong Capital Stewardship. We have developed and are executing against a disciplined framework for capital deployment that balances long-term investment to improve the through-cycle profitability of the business with return of cash to shareholders. We are focused on improving our return on invested capital and remain committed to delivering strong and sustainable total shareholder return over the long-term. Our approach to deploying cash is disciplined with a two-pronged framework of critical funding and discretionary choices to create value. From a critical funding perspective, we have our ongoing base maintenance and health, safety and environmental capital expenditures including our enterprise programs to support long-term operational excellence and risk mitigation. We have and will continue to flex this level of spend, as needed or required, to address critical enterprise risk mitigation, regulatory compliance and sustainability programs. We believe that our dividend, which has grown since its initiation in 2021, serves as a dependable return of cash to our shareholders and fits very well within this framework supported by annual operating cash flow. The timing, declaration, amount and payment of dividends to stockholders, if any, will be within the sole discretion of our Board of Directors ("Board"). All further capital allocation is discretionary where we fund growth and cost saving programs at robust returns, inorganic opportunities and share repurchases. Our high-return growth and cost savings capital project pipeline target improvement in production rate, cost, quality and yield. As an example, we are accelerating profitable growth through our multi-year SUSTAIN program's planned expansion in granular ammonium sulfate production. We continue to pursue a highly-selective acquisition and alliance strategy to supplement our organic sales by broadening our customer base, developing our technology and product portfolios, and enhancing our cash flow profile and margin stability. On an ongoing basis we evaluate options to return cash to shareholders and maintain sufficient capacity under our current share repurchase authorization.

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Industry Overview

Nylon Solutions. Nylon is sold globally as a polymer resin that is drawn into fiber for textiles and carpet and into filament for industrial applications; compounded for engineering plastics, including for automotive end-use; and extruded into film for food and industrial packaging applications. While global Nylon 6 production and utilization data reflect aggregate conditions across all regions, market dynamics and value chains have been operating more regionally in recent years. During 2025, approximately 7.7 million metric tons of Nylon 6 resin were produced and consumed globally. Utilization of Nylon 6 production capacity was approximately 56% in 2025, influenced by supply and demand fundamentals and operating rates in China and the rest of Asia, which represents nearly 80% of total Nylon 6 capacity. In contrast, utilization rates in 2025 for caprolactam, the key building block for Nylon 6, were approximately 74% globally and over 80% in the United States reflecting more balanced regional supply and demand conditions. Caprolactam utilization was also above 80% in China, which was comparatively higher than operating rates observed in Europe and the rest of Asia (55%-65% range).

Market growth typically tracks global GDP growth over the long-term but varies by end-use. Generally, prices for Nylon 6 resin and caprolactam reflect supply and demand trends in the marketplace as well as the value of the basic raw materials used in the production of caprolactam, consisting primarily of benzene and, depending on the manufacturing process utilized, natural gas and sulfur. The global prices for nylon resin typically track a spread over the price of caprolactam, which in turn tracks as a spread over benzene because the key feedstock materials for caprolactam, phenol or cyclohexane, are derived from benzene. This price spread has historically experienced variation as a result of global changes in supply and demand. Nylon 6 resin prices generally track caprolactam prices, although prices set above the average commodity spread are achievable when nylon resin manufacturers, like AdvanSix, formulate and produce differentiated nylon resin products for current and new customer applications. Our differentiated Nylon 6 products, such as our wire and cable, and co-polymer offerings, are typically valued at a higher level than commodity resin products. We believe that Nylon 6 end market growth will continue to generally track global GDP over the long-term. Carpet is the largest end-use for Nylon 6 in North America and has seen stable to declining demand growth for a number of years reflecting shifts in consumer preferences to hard flooring versus soft and the previous substitution to lower-cost polyester. The housing sector had seen an improving trend in recent years, however, residential construction markets have slowed through 2025 reflecting higher interest rates. While Nylon 6 has a stronger presence in commercial carpet applications, including hospitality, institutional and offices, where the material is preferred for its durability and performance characteristics, growth in both residential and commercial markets has been subdued. A lower interest rate environment, in time, is expected to favorably impact building and construction, however, we expect continued weak demand through 2026. Applications such as engineered plastics and packaging have potential to grow at faster rates given certain macrotrends.

Varying regional dynamics, including competitive intensity and trade flows continue to impact regional pricing. Despite long supply and demand fundamentals, estimated operating rates out of China remain at multi-year highs resulting in continued nylon exports to other regions, namely southeast Asia. In North America, where we primarily participate, demand has been weak, with continued softness in building and construction, food packaging and engineering plastics applications used largely in the automotive industry.

Plant Nutrients. Ammonium sulfate is used as a fertilizer providing the key nutrients of sulfur and nitrogen for major agricultural crops globally such as corn, wheat, coffee, sugar, cotton and rice. Ammonium sulfate fertilizer products are primarily sold in North and South America. As of December 31, 2025, ammonium sulfate fertilizer accounts for approximately 6% of the global market for nitrogen fertilizer and over 40% of the global market for sulfur fertilizer. Global prices for ammonium sulfate are influenced by several factors including the price of urea, which is the most widely used source of nitrogen-based fertilizer in the world. Other global factors driving ammonium sulfate fertilizer demand are general agriculture trends, including the price of crops. Evidence continues to demonstrate that farmers understand the investment trade off in driving better yield while managing their cost structure and profitability. Strong underlying agriculture fundamentals coupled with elevated global energy input costs and tighter nitrogen fertilizer supply and demand dynamics drove significantly higher nutrient values through most of 2021 and 2022. Nitrogen fertilizer pricing declined through 2023 amid lower energy costs and increases in global supply availability, but remained favorable relative to historical levels. Pricing and spreads strengthened in 2024 and margins remained favorable in 2025 despite rising raw material inputs, which we believe is reflective of an increasingly recognized sulfur value proposition and observed growth in demand. Our ammonium sulfate product is positioned with the added value proposition of sulfur nutrition to increase yields of key crops. In addition, due to its nutrient density, the typical ammonium sulfate product delivers pound for pound the most readily available sulfur and nitrogen to crops as compared to other fertilizers. We produce a high-quality granular grade of ammonium sulfate to meet the growing demand of our customers. We expect sulfur nutrition demand to grow 3%-4% per year with potential upside driven by increased adoption of ammonium sulfate on soybeans. In addition, there are significant anti-dumping duties in place in the U.S. against Chinese ammonium sulfate, which are subject to customary sunset review in 2028. We also directly supply packaged ammonium sulfate to customers, primarily in North America, and have diversified and optimized our offerings to include spray-grade adjuvants to support crop protection, as well as other specialty fertilizers and products for industrial use.

Chemical Intermediates. Chemical intermediates are used as key inputs for a variety of end market products including construction materials, paints and coatings, packaging agrochemical, water treatment, pharmaceutical and consumer applications. The primary products are acetone, phenol, AMS, cyclohexanone and a range of alkyl and specialty amines. Acetone and phenol represent

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approximately 59% and 8%, respectively, of our chemical intermediates sales. Acetone global demand totals approximately 7.6 million metric tons with the U.S. representing approximately 13% of the global market. Major end-uses for acetone are methyl methacrylate, polycarbonate, epoxy resins, ketones and solvents used widely in automotive and construction, as well as agrochemicals. Polycarbonate and epoxy resins are the largest global end-use for phenol, followed by phenolic resins which are used in construction products, such as wood resins. Industry operating rates for phenol and acetone production have fallen in recent years and are estimated to be approximately 70% globally and low to mid 60% in the U.S. with reduced consumer demand and significant additional capacity additions in Asia, particularly China. Prices for acetone are influenced by its own supply and demand dynamics but can also be influenced by the underlying move in propylene input costs. In the U.S., where we primarily sell our acetone, there were elevated levels of acetone imports during 2018 and 2019 given high industry operating rates globally, which pressured regional pricing and spreads. As a result of strong global acetone demand driven by favorable COVID-related acetone derivative drivers (hand sanitizers and acrylic screens) in addition to the implementation of acetone anti-dumping duties, acetone imports into the U.S. declined in recent years, creating more favorable supply and demand conditions for the product and improved pricing. Industry-realized acetone prices over refinery grade propylene costs generally remain healthy and continued balanced to tight global supply and demand as lower global phenol operating rates continue to persist. Looking forward, further reductions in interest rates would likely support phenol demand in building and construction applications for both renovation and new builds. Demand across the rest of the Chemical Intermediates portfolio is mixed overall though these products do represent platforms serving high-value applications in support of longer-term growth and profitability.

Competition

Competition across our product offerings is based on a variety of factors including price, reliability of supply, quality, product innovation, breadth of product line, R&D efforts and technical and managerial capability. While the competitive position of our individual products varies, we believe we are a significant competitor in each major product class. For Nylon Solutions, we compete with integrated manufacturers such as BASF Corporation, UBE Corporation, DOMO Chemicals GmbH, Envalior, Highsun Group Holdings Ltd., and Sinopec Limited. For Plant Nutrients, like Nylon, we compete with caprolactam/ammonium sulfate co-product manufacturers and direct ammonium sulfate producers such as Pasadena Commodities International and Nutrien Ltd. For Chemical Intermediates, we compete with stand-alone phenol and acetone producers, such as INEOS Phenol and Altivia, and, with respect to our amines product line, our key alkyl amines U.S.-based competitor is Eastman Chemical Company.

Product Overview

Nylon and Caprolactam

We manufacture our Nylon 6 resin in our Chesterfield plant. We sell our Nylon 6 resin globally, primarily under the Aegis® brand name. In 2025, our Nylon products generated $310 million of sales. In 2025, 2024 and 2023, Nylon sales were 20%, 23% and 23% of our total sales, respectively.

We produce caprolactam, the key monomer used in the production of Nylon 6 resin, at our Hopewell plant using phenol produced at our Frankford plant and sulfur and natural gas obtained from third-party suppliers. In 2025, caprolactam generated $271 million of sales. In 2025, 2024 and 2023, caprolactam sales were 18%, 18% and 20% of our total sales, respectively.

Plant Nutrients

Ammonium sulfate fertilizer is produced simultaneously with caprolactam as part of our integrated manufacturing process at our Hopewell plant. We manufacture this product in a ratio of approximately four pounds of ammonium sulfate to one pound of caprolactam. Our co-product competitors typically produce approximately two pounds or less of ammonium sulfate for each pound of caprolactam. We are targeting converting approximately 75% of the ammonium sulfate we produce into higher-value granular form by year end 2026 in connection with our SUSTAIN (Sustainable U.S. Sulfate to Accelerate Increased Nutrition) program. We also manufacture and sell ammonia, sulfuric acid and carbon dioxide as part of our integrated operations at Hopewell. We sell ammonium sulfate under the brand name Sulf-N®, and in 2025, our Plant Nutrients products generated $564 million of sales. In 2025, 2024 and 2023, Plant Nutrient sales were 37%, 30% and 31% of our total sales, respectively.

Chemical Intermediates

We manufacture, market and sell chemical intermediates to a range of customers for use in many different types of end-products. In 2025, chemical intermediates generated $377 million of sales, of which $281 million, or 75%, came from sales of acetone, phenol and cyclohexanone, and $96 million, or 25%, came from sales of our other chemical intermediates. In 2025, 2024 and 2023, sales of chemical intermediates were 25%, 29% and 26% of our total sales, respectively.

The phenol we produce at our Frankford plant is a key chemical intermediate used in our caprolactam manufacturing process. The majority of the phenol we produce is used in production of caprolactam and other chemical intermediates at Hopewell. Any remaining

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phenol is sold to customers for use in their product applications such as phenolic resins, alkyl phenols and Bisphenol A used for epoxy resins and polycarbonate.

All our acetone is sold to customers for use in products such as methyl methacrylate, polycarbonate, epoxy resins, ketones and solvents used widely in automotive and construction, as well as agrochemicals. Acetone is typically used by our customers as a key raw material in the production of a variety of other chemicals which are then used in the applications listed above.

We also produce and sell AMS, cyclohexanone, oximes and cyclohexanol to customers for use in end-products such as resins, inks, paints, coatings and electronic components. The majority of cyclohexanone we produce is used in our caprolactam manufacturing process with the remainder sold to customers.

Through our U.S. Amines sites, we also produce and sell alkyl-amines and specialty amines which are used in agrochemical intermediates, water treatment and pharmaceutical applications.

Raw Materials

The primary raw material used in our manufacturing process is cumene, which is produced from benzene and propylene. We purchase cumene from multiple suppliers to ensure stability of supply and optimal terms. Other important raw materials used in our manufacturing process are natural gas and sulfur, which are used to produce caprolactam and ammonium sulfate. We purchase natural gas and sulfur from a diverse set of suppliers.

Historically, we have been able to renew contracts with our suppliers and obtain sufficient quantities of cumene, sulfur, natural gas and any other key raw materials. Global supply and demand can significantly impact the price of our key raw materials, and historically prices have been cyclical. Prices for our key raw materials are typically on a monthly settlement basis for benzene, propylene and natural gas, or on a quarterly settlement basis for sulfur. We mitigate our exposure to commodity price risk primarily through the use of medium- and long-term, formula-based price contracts with our suppliers and formula-based price agreements with customers which structurally pass through increases or decreases in raw material costs. While formula or index-based pricing agreements are more common for benzene and propylene across our Nylon Solutions and Chemical Intermediates portfolio, a portion of our natural gas and sulfur exposure is also structurally passed through in certain customer agreements. Sales in our Plant Nutrients business line are priced on a freely negotiated basis.

Sales, Marketing and Distribution

We have a sales force with global reach, long-standing customer relationships and deep expertise with our products, product applications and end markets. In Nylon and Chemical Intermediates we predominantly sell directly to our customers, primarily under contracts but also through spot transactions under purchase orders and through distributors. In Plant Nutrients, the majority of sales, while to long standing customers, are freely-negotiated transactions under purchase orders.

Our products are supported by our global logistics capability that we employ to ensure reliable and timely delivery to our customers while maximizing distribution resources and efficiency.

Customers

AdvanSix serves approximately 375 customers annually, primarily in the United States, with global capabilities, spanning a wide variety of industries. In 2025, the Company's 10 largest customers accounted for approximately 40% of total sales. Our largest customer is Shaw Industries Group Inc. ("Shaw"), one of the world's largest consumers of caprolactam and Nylon 6 resin. We sell caprolactam and Nylon 6 resin to Shaw under a long-term agreement. Sales to Shaw were 10% of our total sales for the years ended December 31, 2025 and 2024, and 11% for the year ended December 31, 2023. We typically sell to our other customers under master services agreements, with primarily one-year terms, or by purchase orders. We have historically experienced low customer turnover.

Seasonality

Our ammonium sulfate fertilizer product line experiences quarterly sales seasonality reflecting both geographical and product sales mix considerations based on the timing and length of the growing seasons in North and South America. The North American fertilizer season typically runs from July, when the value chain begins restocking fertilizer, through June of the following year, when most application for the year’s planting is completed. The new season fill begins in the third quarter and proceeds sequentially into the following spring, which is the peak period for crop fertilizer application. As a result of this pattern, North American ammonium sulfate demand and pricing, particularly for our higher-value granular product, are typically strongest in the first half of the year through application for the spring crop and then decline in the second half of the year. Ammonium sulfate industry prices in the corn belt have declined approximately 12% from the second quarter to the third quarter, on average, since 2016. Due to the ammonium

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sulfate fertilizer sales cycle, we occasionally build higher inventory balances because our production is continuous throughout the year and not tied to seasonal demand for fertilizers. Sales of most of our other products have generally been subject to minimal, or no, seasonality.

Research & Development and Intellectual Property

We believe success in our industry is driven not only by operational excellence and cost position but also through technological strength and innovation. Our R&D activities are regularly prioritized and funded with a stage gate approach with a primary emphasis on improving our chemical manufacturing processes to increase efficiency, capacity and productivity, lowering production and operating costs, and innovating and developing new product applications.

We benefit from numerous patents and trademarks that we own. We sell our Nylon 6 resin under the Aegis® brand name and our ammonium sulfate fertilizer under the Sulf-N® brand name. Certain of our chemical intermediates are sold under the brand names of Nadone®, Naxol® and EZ-Blox®. We also benefit from technology protected by trade secrets, know-hows and other proprietary measures particularly on aspects pertaining to product formulations, processes and technologies. At the present time, we do not consider any individual patent, trademark or licensing or distribution rights related to a specific process or product to be of material importance in relation to our overall business. In our judgment, our intellectual property rights are adequate for the conduct of our business and for sustained competitive advantages. We intend to continue taking steps as necessary to protect our intellectual property, including when appropriate, filing patent applications for inventions that are deemed important to our business, defending our patent rights, and enforcing our exclusivity positions worldwide.

We conduct R&D at our technology center with researchers at our manufacturing site in Chesterfield, Virginia, although certain of our manufacturing technology-specific R&D activities are conducted on site where manufacturing takes place.

Regulation and Environmental Matters

We are subject to various federal, state, local and foreign government requirements regarding protection of human health and the environment. Compliance with these laws and regulations results in higher capital expenditures and costs. We believe that, as a general matter, our policies, practices and procedures are properly designed to prevent unreasonable risk of environmental impact, and any resulting financial liability. Some risk of environmental impact is, however, inherent in some of our operations and products, as it is with other companies engaged in similar businesses.

We are and have been engaged in the handling, manufacture, use and disposal of many substances classified as hazardous by one or more regulatory agencies. It is possible that future knowledge or other developments, such as improved capability to detect substances in the environment or increasingly strict environmental laws, standards and enforcement policies, could bring into question our current or past handling, manufacture, use or disposal of these substances.

Among other environmental laws and regulations, we are subject to the Comprehensive Environmental Response, Compensation and Liability Act; the Resource Conservation and Recovery Act and similar state, foreign and global laws for management and remediation of hazardous materials; the Clean Air Act and the Clean Water Act, for protection of air and water resources; the Toxic Substance Control Act, for regulation of chemicals in commerce and reporting of potential known adverse effects. There are also numerous other federal, state, local and foreign laws and regulations governing materials transport and packaging, under which we may be designated as a potentially responsible party liable for cleanup costs associated with current operating sites and various hazardous waste sites.

Our business may be impacted by potential climate change legislation, regulation or international treaties or accords in the foreseeable future. We will continue to monitor emerging developments in this area.

Our accounting policy for environmental expenditures is discussed in “Note 2. Summary of Significant Accounting Policies” to the audited Consolidated Financial Statements included in this Form 10-K. We continuously seek to improve our health, safety and environmental ("HSE") performance. We have expended funds to comply with environmental laws and regulations and expect to continue to do so.

Our Frankford and Hopewell facilities are regulated facilities under the Maritime Transportation Security Act of 2002 due to the nature of our operations and the proximity of the facilities to adjacent waterways. As a result, we are required to comply with numerous regulations administered by the Department of Homeland Security, including the development and implementation of compliant security procedures and protocols. Additionally, sales of certain of our products, such as acetone and amines, may implicate List II or other considerations under the Drug Enforcement Act. Such classifications subject us to further compliance audits by the relevant federal and state agencies and place ongoing restrictions on our sales activities.

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See “Risk Factors – Extensive environmental, health and safety laws and regulations applicable to our operations, including initiatives related to discharges into the air and water, hazardous waste, sustainability, global warming and climate change, may result in substantial costs and unanticipated loss or liability, which could adversely affect our business, financial condition and results of operations” in Item 1A.

Human Capital Management

As a company, we recognize that our people are our greatest asset and the foundation of our success. We feel a deep sense of responsibility to provide a safe, inclusive and engaging workplace for all our employees and contractors, and strive for a zero-incident safety culture. Our core values of Safety, Integrity, Accountability and Respect guide our day-to-day activities and inform our broader business strategy as we drive safe, stable and sustainable operations through an ownership mentality aligned to shareholder value creation. Our Board, along with management and cross-functional teams, work closely to evaluate and proactively address human capital management topics such as safety, employee development, employee benefits and employee engagement and inclusion.

Employees

As of December 31, 2025, the Company employed approximately 1,410 people. Of this total, approximately 560 are salaried employees and approximately 850 are hourly employees. Approximately 720 employees are covered under collective bargaining agreements that expire between 2028 and 2029. The Company strives to maintain positive and productive relationships with all of its employees, including the unions representing those employees.

Oversight and Management

Our Board and Board committees provide oversight on various human capital management matters. As noted in their respective charters:

•Our Health, Safety, and Environmental Committee oversees policies and programs relating to HSE matters, including process safety, HSE management systems and compliance with HSE regulations and compliance.

•Our Nominating and Governance Committee annually evaluates the effectiveness of our corporate governance framework and corporate social responsibility policies, goals and programs, including oversight of sustainability matters, community engagement and government affairs, as well as such other matters regarding the Company's role as a responsible corporate citizen.

•Our Audit Committee exercises oversight of enterprise risk assessments and risk management including with respect to current and emerging labor and human capital management risks and seeks to mitigate exposure to those risks.

•Our Compensation and Leadership Development Committee is responsible for oversight of the performance, development and retention of senior and executive management necessary to support the growth and success of the Company.

Health and Safety

At AdvanSix, safety is our number one core value — we “Live Safety” in all we do. “Live Safety” is an interdependent concept meaning that employees care not only for their own safety, but for the safety of their teammates and the communities in which we operate.

AdvanSix is a Responsible Care® company with a focus on personal and process safety and advancing as a sustainable enterprise. Responsible Care® is the environmental, health, safety and security performance initiative of the American Chemistry Council (ACC). AdvanSix has demonstrated its commitment to the Responsible Care® Guiding Principles, which encourage ethical leadership, product safety, a culture which reduces and manages process safety risk, reduction of pollution and waste, and continuous improvement in environmental, health, safety and security performance.

As an organization, we maintain a relentless focus on continuous improvement and our vision is zero injuries for employees and contractors. Our CARE program — Courage to Act, Respond and Engage — was launched in 2019 and inspires us to Live Safety in all we do. We use the industry standard Total Case Incident Rate ("TCIR") to measure our ongoing safety performance and compare with benchmarks. TCIR is defined as the number of occupational injuries and illnesses per 100 employees. Our TCIR was 1.48 in 2025, 1.16 in 2024 and 0.97 in 2023.

Engagement and Inclusion

At AdvanSix, we strive for an inclusive work environment that fosters respect for all our coworkers, customers, suppliers and business partners. We value the diversity reflected in the various backgrounds, experiences, and ideas of our directors, employees, contractors, and other stakeholders. We strive to represent the communities in which we operate, celebrate our differences, inspire belonging, and are tenacious in our pursuit of bringing out the best in people both individually and collectively. Our Code of Conduct outlines our commitment to provide employees a workplace that is free from discrimination or harassment (specifically related to gender, race,

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disability, ethnicity, nationality, religion and sexual orientation) or personal behavior not conducive to a productive and inclusive work climate. We believe it is important that each employee feels a sense of belonging and is valued as part of the organizational culture we are cultivating, and we feel it is important that each employee sees diverse representation across our AdvanSix team.

We created a program in 2022 for inclusive leadership, ensuring our leaders understand and have the tools to create an inclusive environment where all can thrive. Our third inclusive leadership cohort kicked off a full year of experiential learning commencing in 2024 and concluding in 2025.

AdvanSix also seeks to improve gender equality in the manufacturing industry, starting with supporting science, technology, engineering and math (STEM) education and work in related fields. Supporting Women in Manufacturing (SWiM), an AdvanSix Employee Resource Group, was formed in 2019 with the goal of promoting women in manufacturing, female leadership and growth in STEM-related fields. SWiM seeks to raise awareness on these matters through programs, events and discussions, including networking, professional development, outreach, volunteering and internal programs highlighting leadership and career paths in multiple disciplines. AdvanSix is committed to pay equity for its employees and regularly performs reviews of its compensation practices to evaluate and maintain pay equity in several respects, including by gender, ethnicity and race.

At a national level, AdvanSix continues its participation as a patron level supporter of the American Institute of Chemical Engineers’ ("AIChE") “Doing a World of Good” initiative that actively supports five high priority pillars within the chemical engineering field that align closely with sustainability and environmental, social and governance focus including engagement and inclusion. In addition, AdvanSix supports the Future of STEM Scholars Initiative ("FOSSI"), a national, industry-wide program which provides scholarships to students pursuing STEM degrees at Historically Black Colleges and Universities ("HBCUs") and connections to internships, leadership development and mentoring opportunities. In 2025, we offered summer internships to our FOSSI scholars and two of our FOSSI graduates joined AdvanSix as full-time employees.

Employee Development

AdvanSix seeks to attract the best talent from a diverse range of sources in order to meet the needs of our business now and in the future. We have established strong relationships with community colleges, universities, professional associations and industry groups with a focus on technical positions and development in order to attract talent including by utilizing co-op, internship programs and as a talent pipeline. We have emphasized investing in our talent and focusing on developing our people to incorporate opportunities for advancement based on experiential learning and development. We acknowledge that development is a career-long endeavor and place the greatest emphasis on learning by doing, supported by feedback, training, and self-reflection.

AdvanSix promotes development through training that broadens work-related skills. These include:

•Core competencies for all employees to develop and apply;

•Leadership competencies needed by all employees managing people; and

•Functional competencies that are position specific and used to inform job progression.

We support the continued development of our employees through semi-annual performance and development reviews, including annual enterprise-wide talent development assessments to ensure leadership development and succession planning. We conduct safety and environmental training for new employees as part of HSE orientation, along with job-specific training aligned to roles. Our hands-on coaching and development initiative focused on our front-line teammates is designed to support safe, stable and sustainable operations, providing our operational workforce with the right tools and processes to execute their work efficiently while enabling streamlined decision making to best serve our customers.

A highly trained and engaged workforce is essential for AdvanSix to be our customers’ trusted partner, and those partnerships are built by delivering best-in-class experiences that result in satisfied customers and support shareholder return.

Employee Benefits

Our compensation programs are designed to align employee compensation with Company performance and to provide appropriate incentives in order to attract, retain and motivate our employees. We believe that in order to maintain the strength of our workforce, it is critical to monitor and assess the current business environment and labor market to refine our compensation and benefits programs and other resources available to our employees. We seek to offer compensation that is competitive and consistent with employee positions, skill levels, experience and geographic location. In addition to offering competitive base salaries, AdvanSix structures its compensation programs to balance incentive earnings for both short-term and long-term performance.

Our compensation and benefit programs are designed to support our business strategy through four key objectives:

•Attract and retain best-in-class talent;

•Drive and pay for performance that creates superior results and sustainable stockholder value;

•Manage risk through oversight and sound management; and

•Nurture a culture of employee health and wellness.

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Information about our Executive Officers

The executive officers of AdvanSix, listed as follows, are appointed annually by the Board.

There are no family relationships among them or our Board members.

Other Information

Our Annual Report on Form 10-K, Quarterly Reports on Form 10-Q, Current Reports on Form 8-K and any amendments to those reports are available free of charge on our website (www.AdvanSix.com) under the heading Investors (see SEC Filings) immediately after they are filed with, or furnished to, the Securities and Exchange Commission (the "SEC"). In addition, in this Form 10-K, the Company incorporates by reference certain information from parts of its Proxy Statement for the 2026 Annual Meeting of Stockholders, which will also be available free of charge on our website. Information contained on, or that may be accessed through, our website does not and will not constitute part of this Form 10-K. Our filings with the SEC are also available on the SEC website at www.sec.gov.

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We are a Delaware corporation that was incorporated on May 4, 2016. Our principal executive offices are located at 300 Kimball Drive, Suite 101, Parsippany, NJ 07054. Our telephone number is (973) 526-1800. Our website address is www.AdvanSix.com.