MSC Certificate Place and date: For the issuing office: Shanghai, 20 March 2024 DNV - Business Assurance Building 9, No. 1591 Hongqiao Road, Changning DistrictShanghai China 200336 Zhu Hai Ming Management Representative Lack of fulfilment of conditions as set out in the Certification Agreement may render this Certificate invalid. ACCREDITED UNIT: DNV Business Assurance B.V., Zwolseweg 1, 2994 LB, Barendrecht, Netherlands - TEL: +31(0)102922689. www.dnv.com/assurance MANAGEMENT SYSTEM CERTIFICATE Certificate no.: 7071-1998-AQ-RGC-RvA Initial certification date: 28 April 1998 Valid: 30 March 2024 – 29 March 2027 This is to certify that the management system of PolyOne-Shanghai, China No. 88, Guo Shou Jing Road, Z. Park, China (Shanghai) Pilot Free Trade Zone, Shanghai, China 201203 and the sites as mentioned in the appendix accompanying this certificate has been found to conform to the Quality Management System standard: GB/T 19001-2016 / ISO 9001:2015 This certificate is valid for the following scope: Design and Manufacture of Colour and Additive Concentrates http://www.dnv.com/assurance Certificate no.: 7071-1998-AQ-RGC-RvA Place and date: Shanghai, 20 March 2024 Lack of fulfilment of conditions as set out in the Certification Agreement may render this Certificate invalid.

The payment date will be a date in 2026 determined by the Compensation Committee (or its authorized delegate), which will occur no later than March 15, 2026. Kunkle was employed by Avient from the original grant date of the award through November 1, 2023 (the modification date). Kunkle was employed by Avient from the original grant date of the award through November 1, 2023 (the modification date).

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. The site of the system user is certified as: Compounding Plant The scope of the certificate includes the following chain of custody options: (not applicable for paper traders) Mass balance Warszawa, 30.12.2024 Place and date of issue Stamp, Signature of issuing party The issuing Certification Body is responsible for the accuracy of this document. 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.

If Buyer has a dispute with respect to an invoice, Buyer must notify Seller within seven (7) business days after the date of invoice. Any times or dates for delivery communicated by Seller (including those contained in Seller’s order confirmation) are estimates only and are not terms of the sale. Unless Seller and Buyer have expressly agreed to a firm delivery date term in a single writing signed by both parties, delay in delivery of any Products shall not relieve Buyer of its obligation to accept delivery thereof.

If Buyer has a dispute with respect to an invoice, Buyer must notify Seller within seven (7) business days after the date of invoice. Any times or dates for delivery communicated by Seller (including those contained in Seller’s order confirmation) are estimates only and are not terms of the sale. Unless Seller and Buyer have expressly agreed to a firm delivery date term in a single writing signed by both parties, delay in delivery of any Products shall not relieve Buyer of its obligation to accept delivery thereof.

If Buyer has a claim with respect to an invoice, Buyer must notify Seller within seven (7) business days after the date of the invoice. Any times or dates for delivery communicated by Seller (including those contained in Seller’s order confirmation) are estimates only and are not terms of the sale. Unless Seller and Buyer have expressly agreed to a firm delivery date term in a single writing signed by both parties, delay in delivery of any Products shall not relieve Buyer of its obligation to accept delivery thereof.

If Buyer has a dispute with respect to an invoice, Buyer must notify Seller within seven (7) business days after the date of invoice. Any times or dates for delivery communicated by Seller (including those contained in Seller’s order confirmation) are estimates only and are not terms of the sale. Unless Seller and Buyer have expressly agreed to a firm delivery date term in a single writing signed by both parties, delay in delivery of any Products shall not relieve Buyer of its obligation to accept delivery thereof.

If Buyer has a dispute with respect to an invoice, Buyer must notify Seller within seven (7) business days after the date of invoice. Any times or dates for delivery communicated by Seller (including those contained in Seller’s order confirmation) are estimates only and are not terms of the sale. Unless Seller and Buyer have expressly agreed to a firm delivery date term in a single writing signed by both parties, delay in delivery of any Products shall not relieve Buyer of its obligation to accept delivery thereof.

If Buyer has a dispute with respect to an invoice, Buyer must notify Seller within seven (7) business days after the date of invoice. Any times or dates for delivery communicated by Seller (including those contained in Seller’s order confirmation) are estimates only and are not terms of the sale. Unless Seller and Buyer have expressly agreed to a firm delivery date term in a single writing signed by both parties, delay in delivery of any Products shall not relieve Buyer of its obligation to accept delivery thereof.

Each invoice is deemed approved by Buyer unless Buyer notifies the Seller within seven (7) business days after the date of invoice as to the incorrectness of such invoice. 7. Any times or dates for delivery communicated by Seller (including those contained in Seller’s order confirmation) are estimates only and are not terms of the sale. Unless Seller and Buyer have expressly agreed to a firm delivery date term in a single writing signed by both parties, delay in delivery of any Products shall not relieve Buyer of its obligation to accept delivery thereof.