_______________________ Vice President, Accreditation Services For the Accreditation Council Certificate Number 0514.02 Valid to December 31, 2021 Revised September 21, 2021 0514-02s SCOPE OF ACCREDITATION TO ISO/IEC 17025:2017 Test Method or Standard: Test Description: 0514-02c

Richardson, Executive Vice President, Chief Financial Officer Robert M. Garratt, Senior Vice President, Chief Commercial Officer Lisa K. Kunkle, Senior Vice President, General Counsel and Secretary(1) Joel R.

Patterson, Executive Vice President and Chief Operating Officer said, "Our first quarter performance highlights accelerating momentum driven by Specialty platform growth and impressive year-over-year gains from Performance Products and Solutions and Distribution as well. Executive Vice President and Chief Financial Officer, Bradley C. DeLuca Vice President, Investor Relations PolyOne Corporation +1 440-930-1226 isaac.deluca@avient.com

Každý stát v USA, stejně jako více než 100 zemí mimo USA, má své antimonopolní zákony. Například domluvené stanovení cen je trestným činem, který lze trestat odnětím svobody a vysokými pokutami – až do výše 1 milionu USD pro jednotlivce a 100 milionů USD nebo více pro společnosti. Utlumení nabídek znamená, že jeden nebo více konkurentů, od kterých by se jinak očekávalo předložení nabídky nebo kteří dříve nabídky předkládali, se dohodnou, že se zdrží nabídky nebo svou dříve předloženou nabídku stáhnou, aby byla přijata nabídka dohodnutého vítězného konkurenta. 3 3.

Any action which may be taken at a meeting of the Committee will be deemed the action of the Committee if all of the Committee members execute a written consent and the consent is filed with the Corporate Secretary. 2 The Audit Committee shall meet periodically with management, the Vice President of internal audit and the independent auditor in separate executive sessions. Review and approve the appointment and replacement of the Vice President of internal audit. 5 2.

See instructions. 6 City, state, and ZIP code Requester’s name and address (optional) 7 List account number(s) here (optional) Part I Taxpayer Identification Number (TIN) Enter your TIN in the appropriate box. Line 6 Enter your city, state, and ZIP code. Routine uses of this information include giving it to the Department of Justice for civil and criminal litigation and to cities, states, the District of Columbia, and U.S. commonwealths and possessions for use in administering their laws.

She was Executive Vice President, then Corporate Executive Vice President, at Celanese Corporation, a global hybrid chemical company, from 2007 to 2010. Garratt Senior Vice President, Chief Commercial Officff er Craig M. Garratt, who had previously served as Senior Vice President, PPS, was named as Senior Vice President, Chief Commercial Officff er on April 18, 2016.

Beggs, Senior Vice President and Chief Financial Officer, Avient Corporation. 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. 6 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, Marketing and Communications Avient Corporation +1 440-930-3162 kyle.rose@avient.com mailto:giuseppe.disalvo@avient.com mailto:kyle.rose@avient.com 7 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, 2023 2022 2023 2022 Sales $ 753.7 $ 823.3 $ 2,423.8 $ 2,606.5 Operating Income 34.3 40.6 153.7 242.9 Net income (loss) from continuing operations attributable to Avient shareholders 5.1 (27.4) 48.0 99.8 Basic earnings per share from continuing operations attributable to Avient shareholders $ 0.06 $ (0.30) $ 0.53 $ 1.09 Diluted earnings per share from continuing operations attributable to Avient shareholders $ 0.06 $ (0.30) $ 0.52 $ 1.08 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.

Beggs, Senior Vice President and Chief Financial Officer, Avient Corporation. 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 mailto:giuseppe.disalvo@avient.com mailto:kyle.rose@avient.com 7 Attachment 1 Avient Corporation Summary of Condensed Consolidated Statements of Income (Unaudited) (In millions, except per share data) Three Months Ended December 31, Year Ended December 31, 2021 2020 2021 2020 Sales $ 1,201.5 $ 997.0 $ 4,818.8 $ 3,242.1 Operating Income 74.0 65.0 381.2 189.3 Net income from continuing operations attributable to Avient shareholders 29.8 74.2 230.8 132.0 Basic earnings per share from continuing operations attributable to Avient shareholders $ 0.33 $ 0.81 $ 2.53 $ 1.47 Diluted earnings per share from continuing operations attributable to Avient shareholders $ 0.32 $ 0.81 $ 2.51 $ 1.46 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.

The underlying growth in these regions helped offset softer demand in Europe and Southeast Asia." 2 2024 Outlook “Looking ahead to the second quarter, we expect adjusted EPS of $0.71, a 13% increase over the prior year," said Jamie Beggs, Senior Vice President and Chief Financial Officer, Avient Corporation. 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, Marketing and Communications Avient Corporation +1 440-930-3162 kyle.rose@avient.com mailto:giuseppe.disalvo@avient.com mailto: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 March 31, 2024 2023 Sales $ 829.0 $ 845.7 Operating income 94.0 57.1 Net income from continuing operations attributable to Avient shareholders 49.4 20.8 Diluted earnings per share from continuing operations attributable to Avient shareholders $ 0.54 $ 0.23 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.