Seller warrants good and clear title in goods subject to the sale (“Product”) and that the Product conforms at the time of shipment to a Certificate of Analysis, a Certificate of Compliance, or a Product Specification Sheet, if any such document exists, and other specifications signed by Seller (“Specifications”).

P O L Y O N E C O R P O R A T I O N Exhibit 31.1 CERTIFICATION I, Stephen D. P O L Y O N E C O R P O R A T I O N Exhibit 32.2 CERTIFICATION PURSUANT TO 18 U.S.C. ANNUAL CERTIFICATIONS PolyOne Corporation included as Exhibits 31.1 and 31.2 to its Annual Report on Form 10-K for 2011, filed with the Securities and Exchange Commission, certificates of its Chief Executive Officer and Chief Financial Officer certifying the quality of PolyOne’s public disclosure.

We hold the American Chemistry Council's certification as a Responsible Care Management System® (RCMS) company. s/ Ernst & Young LLP Cleveland, Ohio February 22, 2023 Exhibit 31.1 CERTIFICATION I, Robert M. AVIENT CORPORATION Exhibit 32.2 CERTIFICATION PURSUANT TO 18 U.S.C.

Further, we recently achieved the American Chemistry Council's certification as a Responsible Care Management System® (RCMS) company. Wulfsohn POLYONE CORPORATION68 Exhibit 31.1 CERTIFICATION I, Robert M. POLYONE CORPORATION Exhibit 32.2 CERTIFICATION PURSUANT TO 18 U.S.C.

Seller warrants good and clear title in goods subject to the sale (“Product”) and that the Product con- forms at the time of shipment to a Certificate of Analysis, a Cer- tificate of Compliance, or a Product Specification Sheet, if any such document exists, and other specifications signed by Seller (“Specifications”). Säljaren garanterar att de produkter som är föremål för försäljningen (”Produkten”) är fria från rättsliga fel och att Produkten vid leveranstidpunkten stämmer överens med ett så kallat ”Certificate of Analysis”, ett ”Certificate of Compliance” eller ett ”Product Specification Sheet”, om något sådant existerar, och med andra specifikationer undertecknade av Säljaren (”Specifikationer”).

POLYONE CORPORATION Exhibit 31.1 CERTIFICATION I, Stephen D. Newlin Chairman, President and Chief Executive Officer February 12, 2013 POLYONE CORPORATION Exhibit 31.2 CERTIFICATION I, Richard J. POLYONE CORPORATION Exhibit 32.2 CERTIFICATION PURSUANT TO 18 U.S.C.

FX +4.6% FX -1.5% Total Avient +3.1% Note: Regional Sales Percentages exclude impact of foreign exchange Q2 2024 SEGMENT PERFORMANCE (COLOR, ADDITIVES & INKS) $525 $542 Q2 23 Q2 24 $94 $108 Q2 23 Q2 24 19.9% Sales Adjusted EBITDA (in millions) (in millions) Sales Adjusted EBITDA 10 17.9% +200 bps * * * Adjusted EBITDA Margin % • Organic sales growth in all regions led by Americas • Raw material deflation combined with cost reduction actions drove EBITDA margin expansion + 3% (+5% excluding FX) + 15% (+17% excluding FX) Q2 2024 SEGMENT PERFORMANCE (SPECIALTY ENGINEERED MATERIALS) $301 $308 Q2 23 Q2 24 $60 $64 Q2 23 Q2 24 20.6% Sales Adjusted EBITDA (in millions) (in millions) Sales Adjusted EBITDA 11 19.8% +80 bps * * * Adjusted EBITDA Margin % • Sales growth in consumer, healthcare and building & construction end markets offset by weaker demand in telecommunications • EBITDA margin expansion driven by positive end market mix as well as raw material deflation + 2% (+4% excluding FX) + 7% (+8% excluding FX) 2024 G U IDA N CE FY 2024 GUIDANCE Previous (May 7) Current Adjusted EBITDA $510 to $535 million $515 to $540 million Adjusted EPS $2.50 to $2.65 $2.55 to $2.70 Interest Expense $105 million $105 million Adjusted Effective Tax Rate 23% to 25% 23% to 25% Capital Expenditures ~$140 million ~$140 million 13 Q3 2024: Adjusted EPS of $0.62 14 Highlights • Provides performance updates on 2030 Sustainability Goals • Reduced company’s Scope 1 & 2 GHG emissions by 48% since 2019 • Highlights ESG performance ratings, certifications, and awards, including recent upgrades by Ecovadis to Gold and CDP to A- • Reflects Great Place to Work® culture focused on health, safety and employee engagement 2023 SUSTAINABILITY REPORT 14 Sustainability for a Better Tomorrow 2023 SUSTAINABILITY REPORT 15 • Investor Day to be held December 4, 2024 in New York, NY • The focus will be to do a deep dive on the Company’s strategy • Further details to be communicated 2024 AVIENT INVESTOR DAY AP P EN D IX 18 Performance Additives 15% Pigments 13% TiO2 9% Dyestuffs 2% Polyethylene 10%Nylon 5% Polypropylene 4% Styrenic Block Copolymer 4% Other Raw Materials 38% ~40% hydrocarbon based (Grey shaded materials are hydrocarbon based, includes portion of “Other Raw Materials”) Non-hydrocarbon based materials RAW MATERIAL BASKET SEGMENT DATA U.S. & Canada 41% EMEA 36% Asia 18% Latin America 5% 2023 SEGMENT, END MARKET AND GEOGRAPHY GEOGRAPHY REVENUESEGMENT FINANCIALS Consumer 19% Packaging 23%Industrial 16% Building and Construction 9% Telecommunications 4% Energy 5% Defense 7% END MARKET REVENUE $2,007M $358M $1,138M $224M Sales EBITDA Specialty Engineered Materials Color Additives and Inks $502M$3,143M (1) Transportation 10% Healthcare 7% 20 (1) Total company sales and adjusted EBITDA of $3,143M and $502M, respectively, include intercompany sales eliminations and corporate costs 2023 REVENUE | $2 .0 B ILL ION US & Canada 34% EMEA 37% Asia 21% Latin America 8% END MARKET REGION 21 Packaging 34% Consumer 21% Healthcare 8% Industrial 15% Transportation 9% Building & Construction 10% Telecommunications 1% Energy 2% COLOR, ADDITIVES & INKS 2023 REVENUE | $1 .1 B ILL ION US & Canada 52% EMEA 35% Asia 13% 22 Packaging 5% Consumer 16% Healthcare 6%Industrial 16% Transportation 12% Telecommunications 9% Energy 10% Defense 18% Building & Construction 8% END MARKET REGION SPECIALTY ENGINEERED MATERIALS Packaging 32% Consumer 26% Healthcare 9% Industrial 13% Building & Construction 6% Telecommunications 2% Energy 2% Defense 1% Asia (18% of sales) Transportation 9% 2023 AVIENT REGIONAL SALES Packaging 25% Consumer 13% Healthcare 5% Industrial 18% Building & Construction 9% Energy 5% Defense 8% EMEA (36% of sales)Transportation 13% Packaging 13% Consumer 22% Healthcare 10% Industrial 16% Building & Construction 12% Energy 6% Defense 8% US & Canada (41% of sales) Transportation 9% Packaging 59% Consumer 22% Healthcare 2% Industrial 8% Building & Construction 4% LATAM (5% of sales) Transportation 5% Telecommunications 4% Telecommunications 4% 23 BY END MARKET Reconciliation of Non-GAAP Financial Measures (Unaudited) (Dollars in millions, except for per share data) Senior management uses comparisons of adjusted net income from continuing operations attributable to Avient shareholders and diluted adjusted earnings per share (EPS) from continuing operations attributable to Avient shareholders, excluding special items, to assess performance and facilitate comparability of results.

Through this data, we create safety data sheet sand customer certification statements for intended use and product safety improvements. External third-party certification is an important part of ensuring our products are both safe and produced in alignment with industry standard best practices. Combined, Avient facilities have a total of 286 management system certifications.

We hold the American Chemistry Council's certification as a Responsible Care Management System® (RCMS) company. s/ Ernst & Young LLP Cleveland, Ohio February 22, 2022 Exhibit 31.1 CERTIFICATION I, Robert M. AVIENT CORPORATION Exhibit 32.2 CERTIFICATION PURSUANT TO 18 U.S.C.

We hold the American Chemistry Council's certification as a Responsible Care Management System® (RCMS) company. Wulfsohn POLYONE CORPORATION 67 [THIS PAGE INTENTIONALLY LEFT BLANK] Exhibit 31.1 CERTIFICATION I, Robert M. POLYONE CORPORATION Exhibit 32.2 CERTIFICATION PURSUANT TO 18 U.S.C.