No. 0514.01) 12/11/2023 Page 1 of 1 SCOPE OF ACCREDITATION TO ISO/IEC 17025:2017 AVIENT CORPORATION – ANALYTICAL SOLUTIONS 33587 Walker Road Avon Lake, OH 44012 Stephanie Mims Phone: 440 930 3499 MECHANICAL Valid To: September 30, 2025 Certificate Number: 0514.01 In recognition of the successful completion of the A2LA evaluation process, accreditation is granted to this laboratory to perform the following rubber and plastics tests: Test Description Test Method or Standard Brittleness Temperature (Impact) ASTM D746; ISO 812 Charpy Impact ISO 179-1 Color Determination by Spectrophotometer ASTM D2244, E1331; ISO 7724 Conditioning of Plastics for Testing ASTM D618; ISO 291 Deflection Temperature Under Flexural Load ASTM D648; ISO 75-1, -2 Durometer Hardness (Shore A and D) ASTM D2240; ISO 7619-1 Flexural Properties ASTM D790; ISO 178 Flow Rate (Extrusion Plastometer) ASTM D1238 (Procedures A and B); ISO 1133 Impact Resistance (Izod) ASTM D256; ISO 180 Instrumented Impact ASTM D3763; ISO 6603-2 Specific Gravity/Density ASTM D792 (Method A); ISO 1183-1 Specular Gloss ASTM D523; ISO 2813 Tackiness of Interior Materials BO 061-01 Tear Resistance ASTM D624, D1004; ISO 34 Tensile Properties ASTM D412 (Method A), D638, D882; ISO 37, 527-1, -2, -3, -4, -5 Xenon-Arc Exposure Testing ASTM D2565, G155; SAE J1885 (Withdrawn January 2008), J1960 (Withdrawn January 2008), J2412, J2527; BO-116-01 For the tests to which this accreditation applies, please refer to the laboratory’s Mechanical Scope of Accreditation.

Figure 1. Regarding tensile properties, three additional categories granted positive marks: 1. REFERENCES 1.

Pro Forma Financial Information The Company acquired Avient Protective Materials (“Dyneema”) on September 1, 2022 (the “Acquisition Date”) and sold the Distribution segment on November 1, 2022. WHAT WE DO: MATERIAL SCIENCE 5 CUSTOM FORMULATION FE BRUARY 1 5 , 2023 W EB CAS T Q4 2022 VS. EBITDA Margins (1) 5.4% 11.5% 16.2% 2006 2018 2022PF $142 $408 $592 2006 2018 2022PF 2006 figures exclude joint venture results 2022 pro forma for the acquisition of Avient Protective Materials Adj.

All Rights Reserved 2025 7 Strategic approach to drive sustainable growth Avient sales growth Catalyze the core GROW BUSINESS AT GDP + 1. All Rights Reserved 2025 8 Strategic approach to drive sustainable growth Avient sales growth Build new platforms of scale GROW BUSINESS AT 10% PLUS CAGR 1. All Rights Reserved 2025 Color, Additives & Inks END MARKETS REGIONS 34% 21% 15% 11% 9% 8% Packaging Telecom 1%Energy 1% Transportation Industrial Consumer 34% 37% 20% 9% US & Canada Latin America Asia Europe, Middle East and Africa Healthcare Building & Construction 25Copyright © .

Avient acquired the Clariant Color business on July 1, 2020 (the “Acquisition Date”). Purchase price multiple rapidly declining on strength of business and synergy capture (1) (1) (1) Financial information is pro forma to include a full year of Clariant Color acquisition ($ in millions) 11.9% 16.2% 2019PF 2021 EBITDA Margins (1) SPECIALTY TRANSFORMATION 7% 46% 66% 86% 100% 0% 20% 40% 60% 80% 100% 2005 2010 2015 2021 2022 PF % o f A dj us te d EB IT D A(1 ) JVs Distribution Performance Products & Solutions Specialty (1) Adjusted EBITDA is EBITDA excluding corporate costs and special items (2) Pro forma for the acquisition of Dyneema® and potential divestiture of Distribution (2) 38 CULTURE AND PEOPLE 39 OUR SPECIALTY JOURNEY CONTINUES 40 • Dyneema® brings leading technology and brand with the World’s Strongest Fiber™, deep history of application development and strong management team focused on specialty applications • Dyneema® transaction is aligned with our previously stated acquisition goal of expanding our composites and fiber capabilities • Similar to our other technology expansion acquisitions, Dyneema® allows us to leverage our invest-to-grow strategy • We plan to explore a possible sale of our Distribution business. Avient Specialty Formulators Other Chemical/Specialty Companies Free Cash Flow Conversion (1) 2022E (%) Being asset light helps us to generate strong free cash flow that is in line with other specialty formulators.

TPEE AND TPU FILM MANUFACTURER H O T M E L T A D H E S I V E F I L M • Anti-phenol yellowing after storage • Keep natural color of product • No impact on melt flow ability • Prevented the appearance quality from yellowing after storage • Had no negative impact on the product’s mechanical properties • Extended the shelf life and durability of the product CesaTM Anti-phenolic Yellowing Additive KEY REQUIREMENTS WHY AVIENT AVIENT SOLUTION FUNCTIONALITY + CONVENIENCE LEARN MORE Avient Corporation 1 https://www.avient.com/products/polymer-additives Slide 1: TPEE and TPU Film MANUFACTURER

Pro Forma Financial Information The Company acquired Avient Protective Materials (“Dyneema”) on September 1, 2022 (the “Acquisition Date”) and sold the Distribution segment on November 1, 2022. To provide comparable results, the company references “pro forma” financial metrics, which include the business results of Avient Protective Materials for periods prior to the Acquisition Date, as if the transaction occurred on January 1, 2021 and reflect Distribution as a discontinued operation. GUIDANCE (TOTAL COMPANY) 11 14.8% 15.8% Guidance Actual Adjusted EBITDA Margin % Better-than-expected margins driven by: • Resilient demand for composites and sustainable solutions which improved mix of higher margin applications • Deceleration of raw material inflation • Cost reduction activities Q1 EBITDA BRIDGE (TOTAL COMPANY) 12 $ millions CAI: Price / Mix 19) Inflation (4) SEM: Price / Mix 6) Inflation (4) Net Price Benefit 17) Wage and Energy Inflation (13) Cost Reductions 8) FX (6) Q1 2023 Actual $134) Adjusted EBITDA Q1 2022 Pro Forma $ 176) Demand (48) • Weak demand conditions in-line with previous expectations • Pricing continues to cover inflation of raw materials, wages and energy U.S. & Canada 40% EMEA 38% Asia 17% Latin America 5% Q1 2023 SEGMENT, END MARKET AND GEOGRAPHY GEOGRAPHY REVENUESEGMENT FINANCIALS Consumer 18% Packaging 23% Healthcare 7% Industrial 16% Building and Construction 10% Defense 6%Telecommunications 4% Energy 5% END MARKET REVENUE (1) Total company sales and adjusted EBITDA of $846M and $134M, respectively, include intercompany sales eliminations and corporate costs $537M $91M $310M $64M Sales EBITDA Specialty Engineered Materials Color Additives and Inks $134M$846M (1) 13 Transportation 11% Q1 2023 SALES BY REGION Yo Y C H A N G E ( E X C L .

Pro Forma Financial Information The Company acquired Avient Protective Materials (“Dyneema”) on September 1, 2022 (the “Acquisition Date”) and sold the Distribution segment on November 1, 2022. To provide comparable results, the company references “pro forma” financial metrics, which include the business results of Avient Protective Materials for periods prior to the Acquisition Date, as if the transaction occurred on January 1, 2021 and reflect Distribution as a discontinued operation. GUIDANCE (TOTAL COMPANY) 7 14.8% 15.8% Guidance Actual Adjusted EBITDA Margin % Better-than-expected margins driven by: • Resilient demand for composites and sustainable solutions which improved mix of higher margin applications • Deceleration of raw material inflation • Cost reduction activities Q1 EBITDA BRIDGE (TOTAL COMPANY) 8 $ millions CAI: Price / Mix 19) Inflation (4) SEM: Price / Mix 6) Inflation (4) Net Price Benefit 17) Wage and Energy Inflation (13) Cost Reductions 8) FX (6) Q1 2023 Actual $134) Adjusted EBITDA Q1 2022 Pro Forma $ 176) Demand (48) • Weak demand conditions in-line with previous expectations • Pricing continues to cover inflation of raw materials, wages and energy U.S. & Canada 40% EMEA 38% Asia 17% Latin America 5% Q1 2023 SEGMENT, END MARKET AND GEOGRAPHY GEOGRAPHY REVENUESEGMENT FINANCIALS Consumer 18% Packaging 23% Healthcare 7% Industrial 16% Building and Construction 10% Defense 6%Telecommunications 4% Energy 5% END MARKET REVENUE (1) Total company sales and adjusted EBITDA of $846M and $134M, respectively, include intercompany sales eliminations and corporate costs $537M $91M $310M $64M Sales EBITDA Specialty Engineered Materials Color Additives and Inks $134M$846M (1) 9 Transportation 11% Q1 2023 SALES BY REGION Yo Y C H A N G E ( E X C L .

The company noted that third quarter 2024 GAAP EPS includes $0.07 of special items (see Attachment 3) and $0.16 of intangible amortization expense (see Attachment 1). You are advised to consult any further disclosures we make on related subjects in our reports on Form 10-Q, 8-K and 10-K that we provide to the Securities and Exchange Commission. 5 Investor Relations Contact: Giuseppe (Joe) Di Salvo Vice President, Treasurer and Investor Relations Avient Corporation +1 440-930-1921 giuseppe.disalvo@avient.com Media Contact: Kyle G. Rose Vice President, Corporate Communications Avient Corporation +1 440-930-3162 kyle.rose@avient.com 6 Attachment 1 Avient Corporation Summary of Condensed Consolidated Statements of Income (Unaudited) (In millions, except per share data) Three Months Ended September 30, Nine Months Ended September 30, 2024 2023 2024 2023 Sales $ 815.2 $ 753.7 $ 2,493.9 $ 2,423.8 Operating income 77.2 34.3 243.7 153.7 Net income from continuing operations attributable to Avient shareholders 38.2 5.1 121.2 48.0 Diluted earnings per share from continuing operations attributable to Avient shareholders $ 0.41 $ 0.06 $ 1.32 $ 0.52 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.

Version / Date: 1 (no adjustments) / 30.12.2024 Page 1 of 2 ISCC PLUS Certificate Certificate Number: ISCC-PLUS-Cert-PL214-26100824 Bureau Veritas Polska Sp. z o.o. ul. Version / Date: 1 (no adjustments) / 30.12.2024 Page 2 of 2 Annex I to the certificate: Sustainable materials handled by the certified site (This annex is applicable for all scopes except of Trader, Trader with storage, Warehouse, Logistic centres, MTBE and ETBE) This annex is only valid in connection with the certificate: ISCC-PLUS-Cert-PL214-26100824 issued on 30.12.2024 Input material Output material Add-ons (voluntary)1) Raw material category2) SAI FSA3) FEFAC4) Polypropylene (PP) Plastic Compounds (PP) NO Bio Bio-circular Circular N/A N/A Polyethylene (PE) Plastic Compounds (PE) NO Bio Bio-circular Circular N/A N/A 1) ISCC PLUS add-ons (voluntary application, see www.iscc-system.org for further information): • 202-04: Food Security Standard • 205-02: Consumables • 202-07: Low ILUC-risk feedstock • 205-03: Non GMO for food and feed • 205-01: GHG emission requirements • 205-04: Non GMO for technical markets 2) Bio raw materials complies with the ISCC Principles 1 – 6 for the cultivation and harvesting of sustainable biomass.