MSC Certificate Place and date: For the issuing office: Shanghai, 10 October 2024 DNV - Business Assurance Building 9, No. 1591 Hongqiao Road, Changning District, Shanghai, 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.: 3033-2006-AQ-RGC-RvA Initial certification date: 07 November 2018 Valid: 08 November 2024 – 07 November 2027 This is to certify that the management system of Polyone - Shenzhen Co., Ltd.

Late payments will bear interest at the maximum percent permitted by applicable law, starting from the due date without further warning. 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.

Khandpur, Ph.D.: President and Chief Executive Officer, December 2023 to date. Beggs: Senior Vice President and Chief Financial Officer, August 2020 to date. SARs have contractual terms of ten years from the date of the grant.

Goff Director Date: February 13, 2014 /S/ GORDON D. Harnett Director Date: February 13, 2014 /S/ SANDRA BEACH LIN Sandra Beach Lin Director Date: February 13, 2014 /S/ RICHARD A. Powell Director Date: February 13, 2014 /S/ KERRY J.

Patterson Name (a) Grant Date (b) Grant Date Fair Value of Stock and Option Awards ($) (j) EXECUTIVE COMPENSATION 47 upon the Named Executive Officer remaining in continuous employment through the payment date. McAlindon was employed by PolyOne from the original grant date of the award through June 15, 2015 (the modification date). Option Expiration Date (column (f)) This column shows the expiration dates for each SAR reported in columns (b), (c) and (d).

Newlin: Executive Chairman, May 2014 to date. Goff Director Date: February 13, 2015 /S/ GORDON D. Harnett Director Date: February 13, 2015 /S/ SANDRA BEACH LIN Sandra Beach Lin Director Date: February 13, 2015 /S/ RICHARD A.

Registration number 1019288451 TQ 0004 Status Valid Effective date of status 2017-08-01 Date viewed 2021-02-04 Business's name AVIENT CANADA ULC Business name SPARTECH PLASTIQUES Registration number to validate 1019288451TQ0004 Page 1 of 1Validate a QST Registration Number - Revenu Québec 2/4/2021https://entreprises.revenuquebec.ca/EntNa/SX/SX00/SX00.SXCLT20A.ValiderInscription/...

Delaware The First State Page 1 5799827 8100 Authentication: 202256240 SR# 20210072080 Date: 01-11-21 You may verify this certificate online at corp.delaware.gov/authver.shtml I, JEFFREY W. AND I DO HEREBY FURTHER CERTIFY THAT THE EFFECTIVE DATE OF THE AFORESAID CERTIFICATE OF AMENDMENT IS THE FIFTEENTH DAY OF JANUARY, A.D. 2021.

Garratt's retirement date. Garratt was employed by Avient from the original grant date of the award through July 22, 2024 (the modification date). Garratt was employed by Avient from the original grant date of the award through July 22, 2024 (the modification date).

Certification Structure: Single Certificate Expiry Date: April 26, 2024 Certificate Issue Date: April 27, 2021 Certified Since: April 27, 2018 Dr.