How to register to the Coupa Supplier Portal (CSP) Suppliers Guide For first time Coupa users Registration via email invitation ➢ If you are new to the CSP, you will receive an e-mail from our Coupa system with a unique link to join the Coupa Supplier Portal o The subject of the email will be: Avient Corporation Registration Instructions - Action Required and will come from the email address: do_not_reply@supplier.coupahost.com ➢ Once you click on the Join Coupa button, you will be directed to the CSP to register your account ➢ If you click on the Join Coupa button you will be activating your account and completing the registration.

Microsoft Word - Avient Announces Registration Details for December 4th Investor Day _for Microsite 1 NEWS RELEASE FOR IMMEDIATE RELEASE Avient Announces Registration Details for December 4th Investor Day CLEVELAND – November 4, 2024 – Avient Corporation (NYSE: AVNT), a leading provider of specialized and sustainable materials solutions, will host an Investor Day for the investment community on Wednesday, December 4, 2024, beginning at 10:00 a.m.

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.

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.

AVNT-2021.06.30-News Release 1 NEWS RELEASE FOR IMMEDIATE RELEASE Avient Announces Registration Details for December 9th Investor Day CLEVELAND – November 3, 2021 – Avient Corporation (NYSE: AVNT), a leading provider of specialized and sustainable material solutions, will host an Investor Day for investment professionals on Thursday, December 9, 2021, from 8:00 a.m. to 1:00 p.m., at the New York Marriott Marquis hotel.

POLYONE CORPORATION Exhibit 31.1 CERTIFICATION I, Stephen D. POLYONE CORPORATION 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 2012, 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.

Through this data, we create safety data sheets (SDS), customer certification statements for appropriate use and recommend product safety improvements Global Chemical Control Laws - The current and future focus is on continued Registration, Evaluation, Authorization and Restriction of Chemicals (REACH) assessments and communication on the safe handling of these substances. Global ISO Certificate Library

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.