Avantor, Inc.

REPORT OF INDEPENDENT REGISTERED PUBLIC ACCOUNTING FIRM

To the stockholders and the Board of Directors of Avantor, Inc.

Opinion on the Financial Statements

We have audited the accompanying consolidated balance sheets of Avantor, Inc. and subsidiaries (the "Company") as of December 31, 2025 and 2024, the related consolidated statements of operations, comprehensive income or loss, stockholders' equity, and cash flows, for each of the three years in the period ended December 31, 2025, and the related notes (collectively referred to as the "financial statements"). In our opinion, the financial statements present fairly, in all material respects, the financial position of the Company as of December 31, 2025 and 2024, and the results of its operations and its cash flows for each of the three years in the period ended December 31, 2025, in conformity with accounting principles generally accepted in the United States of America.

We have also audited, in accordance with the standards of the Public Company Accounting Oversight Board (United States) (PCAOB), the Company's internal control over financial reporting as of December 31, 2025, based on criteria established in Internal Control — Integrated Framework (2013) issued by the Committee of Sponsoring Organizations of the Treadway Commission and our report dated February 11, 2026, expressed an unqualified opinion on the Company's internal control over financial reporting.

Basis for Opinion

These financial statements are the responsibility of the Company's management. Our responsibility is to express an opinion on the Company's financial statements based on our audits. We are a public accounting firm registered with the PCAOB and are required to be independent with respect to the Company in accordance with the U.S. federal securities laws and the applicable rules and regulations of the Securities and Exchange Commission and the PCAOB.

We conducted our audits in accordance with the standards of the PCAOB. Those standards require that we plan and perform the audit to obtain reasonable assurance about whether the financial statements are free of material misstatement, whether due to error or fraud. Our audits included performing procedures to assess the risks of material misstatement of the financial statements, whether due to error or fraud, and performing procedures that respond to those risks. Such procedures included examining, on a test basis, evidence regarding the amounts and disclosures in the financial statements. Our audits also included evaluating the accounting principles used and significant estimates made by management, as well as evaluating the overall presentation of the financial statements. We believe that our audits provide a reasonable basis for our opinion.

Critical Audit Matter

The critical audit matter communicated below is a matter arising from the current-period audit of the financial statements that was communicated or required to be communicated to the audit committee and that (1) relates to accounts or disclosures that are material to the financial statements and (2) involved our especially challenging, subjective, or complex judgments. The communication of critical audit matters does not alter in any way our opinion on the financial statements, taken as a whole, and we are not, by communicating the critical audit matter below, providing a separate opinion on the critical audit matter or on the accounts or disclosures to which it relates.

Goodwill Impairment - Distribution reporting unit - Refer to notes 2, 6, and 11 to the financial statements

Critical Audit Matter Description

Goodwill is tested for impairment at the reporting unit level on October 1 of each year or more frequently whenever an event or change in circumstance occurs that would require reassessment of the recoverability of the asset. The Company estimates the fair value of each reporting unit using a weighted average of two valuation methods based on a discounted cash flows method and a guideline public company method. These valuation methods require management to make various assumptions, which include, but are not limited to, future profitability, cash flows, discount rates, weighting of valuation methods, and the selection of comparable publicly traded companies (peer groups). If the Company determines the carrying value of a reporting unit exceeds its fair value, an impairment charge is recorded for the excess. As a result of sustained decreases in the Company’s publicly quoted share price and market capitalization as well as changes in the operating results of the Distribution reporting unit, the Company conducted an interim impairment test as of September 30, 2025, which resulted in a non-cash goodwill impairment charge of $785.0 million. No impairment charges were recorded to the other reporting units as their estimated fair values exceeded their respective carrying amounts.

The principal considerations for our determination that performing audit procedures relating to the Distribution reporting unit’s goodwill impairment analysis is a critical audit matter are (i) the significant judgment by management when developing the fair value estimate of the reporting unit; (ii) a high degree of auditor judgment in evaluating the reasonableness of management’s assumptions under the discounted cash flows method, in particular the estimates of net sales growth and the discount rate; and (iii) an increased extent of effort, including the need to involve our fair value specialists.

How the Critical Audit Matter Was Addressed in the Audit

Our audit procedures over management’s estimates of net sales growth and the discount rate for the Distribution reporting unit included the following, among others:

•We tested the effectiveness of controls over management’s goodwill impairment testing, including those over management’s assumptions of net sales growth and the discount rate under the discounted cash flows method.

•We evaluated management’s ability to accurately forecast net sales growth by comparing actual results to management’s historical forecasts.

•We evaluated the reasonableness of management’s net sales growth by comparing the forecast to historical results and forecasted information included in available peer and industry data.

•With the assistance of our fair value specialists, we evaluated the reasonableness of the discount rate, by (1) testing the underlying information supporting this assumption; (2) testing the mathematical accuracy of the calculations; and (3) developing a range of independent estimates and comparing those to the discount rate selected by management.

•We evaluated the competency and objectivity of management’s specialists who assisted with preparing the discounted future cash flows analysis.

/s/Deloitte & Touche LLP

Philadelphia, Pennsylvania

February 11, 2026

We have served as the Company’s auditor since 2010.