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.

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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. 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.

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.

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.