Avient will share further information during its previously scheduled webcast scheduled for 8:00 a.m. Eastern Time on May 3, 2023. 3 Webcast Details Avient will host a webcast on Wednesday, May 3, 2023 at 8:00 a.m. See Attachment 3 for a definition and summary of special items.

see attachment 3) and 8:00 a.m. Attachment 3

S e e S p e c if ic I n s tr u c ti o n s o n p a g e 3 . 1 Name (as shown on your income tax return). Name is required on this line; do not leave this line blank. 2 Business name/disregarded entity name, if different from above 3 Check appropriate box for federal tax classification of the person whose name is entered on line 1. No. 10231X Form W-9 (Rev. 10-2018) AVIENT CORPORATION ✔ 5 D 33587 WALKER ROAD AVON LAKE, OH 44012 3 4 1 7 3 0 4 8 8 7/20/2020

Sanders joined Avient in April 2024 and has responsibility for all legal functions, including contracts and transactions, M&A, compliance, labor relations, digital information, privacy, and intellectual property.

Home printer OEM HOME PRINTER OEM R E C Y C L E D H I P S I N J E C T I O N C O V E R O F P R I N T E R • Provide PCR-based colorants for a more sustainable solution • Meet both color and mechanical requirements in PCR materials • Offer user-friendly PCR + Colorants solution to address the batch variance problem of PCR in an economical way • Offered revolutionary supply model of PCR + Colorants, ensuring precise quality and color • Helped customers solve the batch variance problem of PCR in a digital way and shortened the color-matching time with PCR Color Prediction Service • Provided on-site technical support to customer Rejoin PCR Colorants KEY REQUIREMENTS WHY AVIENT?

No. 10231X Form W-9 (Rev. 10-2018) AVIENT CORPORATION AVIENT COLORANTS USA LLC ✔ 5 E 33587 WALKER ROAD AVON LAKE, OH 44012 3 4 1 7 3 0 4 8 8 1/15/2021 Form W-9 (Rev. 10-2018) Page 2 By signing the filled-out form, you: 1. The treaty article addressing the income. 3. Check only one box on line 3.

Improved Thermal Stability & Reduced Yellowing Based on APR Critical Guidance Test Data 3mm Plaque Actual APR Tolerance L* 91 >82 da* -0.61 >-3 db* -0.38 1.5 Sample Delta L* Delta b* Reference -7.5 11.3 Reference + RHC -5.6 8.6 INCREASED rPET CONTENT & IMPROVED QUALITY SmartHeat RHC is APR accredited for both Critical Guidance and Bottle-to-Bottle, and is EPBP approved. IMPROVED BOTTLE QUALITY +2% in neck weight +3% in body weight -12% in base weight 8.5g 0.5L bottle, 60% rPET Polymer Weight Distribution Based on commercially produced water bottles, 51,000bph Mechanical Strength Increasing SmartHeat RHC Concentration Based on PTI 14.4g 0.5L water bottles, Instron testing To p Lo ad (l bs ) 14 15 16 17 8 9 10 11 0 20 40 60 80 100 0 50 100 150 200 250 300 350 400 450 Burst Pressure Increasing SmartHeat RHC Concentration Based on 8.5g, 0.5L commercially produced water bottles B ur st P re ss ur e (B ar ) 14 15 16 17 8 9 10 11 0 20 40 60 80 100 0 50 100 150 200 250 300 350 400 450 REDUCED CO2 EMISSIONS Increasing SmartHeat RHC Concentration Based on a commercial process producing 8.5g 0.5L water bottles as 51,000bph 25% reduction in energy consumed during the bottle blowing process En er gy k W Reduce Energy Consumption SmartHeat RHC increases the heat-up rate for preforms, enabling energy reductions for the heating lamps used during the bottle blowing process. This effect contributes towards reducing CO2 emissions. 14 15 16 17 8 9 10 11 0 20 40 60 80 100 0 50 100 150 200 250 300 350 400 450 Increasing SmartHeat RHC Concentration Translates to 25% CO2 reductions based on energy savings reducing CO2 emissions by 114 tonnes per year on one commercial blowing line CO 2 ( to nn es ) 14 15 16 17 8 9 10 11 0 20 40 60 80 100 0 50 100 150 200 250 300 350 400 450 SmartHeat RHC products are supplied in ColorMatrix™ approved packaging and are active as supplied.

POLYMER PRODUCT NAME PROPERTY PERFORMANCE TYPE DOSAGE/LDR MATERIAL CODE ABS FRABS92991 UL 94 Halogen 35% CC10292991WE ABS FRABS52399 UL 94 Halogen 5–14% CC10252399WE HDPE Cesa Flam MB 5101AH UL 94 Halogen 7–16% PEAN698479 Nylon Cesa Flam MB 5728H UL 94 Halogen 8–14% ABA0698450 Nylon Cesa Flam MB 5731NH UL 94 Non-halogen 8–20% ABAN698410 PC Cesa Flam NCA0820018NH UL 94 Non-halogen 2–4% NCA0820018 PC NCAN-Z0N-FN FLMRET 698419 UL 94 Non-halogen 3–8% NCAN698419 PE FRPE94802 ASTM E84 Non-halogen 100% CC103094802F PE FRPE41011 UL 94 Halogen 20–30% CC1034101160 PET Cesa Flam MB 5525NH UL 1441, UL 94 Non-halogen 6–8% NEAN698534 PET FRPET65462 UL 94 Non-halogen 5–12% CC103265462F PET/ PBT Cesa Flam MB 5532NH NFPA 701 Non-halogen 4–6% NBAN698451 PP Cesa Flam MB 5201H UL 94 Halogen 6–30% PPAN698410 PP Cesa Flam MB CT-1629NH Cal TB 133, UL 94 Film, NFPA 701 Non-halogen 6–8% PPAN698428 PP FRPP365370 UL 94 Non-halogen 10–20% CC103653702F PP Copolymer FRPP37654 UL 94 5VA Halogen 100% CC10337654WE PP Copolymer FRPP53484 UL 94 Halogen 10% CC1035348460 PS FRPS62722 ASTM E84 Halogen 2–4% CC10262722WE PS/HIPS Cesa Flam SLA0820014H UL 94 Halogen 4–8% SLA0820014H TPU Cesa Flam 98461NH UL 94 Non-halogen 6–14% RUA0698461 F-SERIES FLAME RETARDANT ADDITIVES HDPE/PE F-Series UL 94 Non-halogen 10–25% PEA0820024 PE F-Series UL 2335, FM 4998 Non-halogen 10–25% PEA0820069

Eastern Time on February 8, 2022. ET on Tuesday, February 8, 2022. See Attachment 3 for a definition and summary of special items.

H61173 Page 1 of 3 Validity 01. 03. 2025  – 29. 02. 2028 Issue 01. 03. 2025 A.Grisard, President SQS F. Validity Avient Colorants Singapore Pte Ltd 8 Third Chin Bee Road Jurong Industrial Estate Singapore 618684 Singapore Design and manufacture of colour and additive concentrates and specialty compounds for the Healthcare and Medical device market. H61173 Page 3 of 3 Validity 01. 03. 2025  – 29. 02. 2028 Issue 01. 03. 2025 The validity of this appendix depends on the validity of the main certificate.