ECOLAB INC.

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APPENDIX A​

Reconciliation of Non-GAAP Financial Measures

This Proxy Statement includes financial measures that have not been calculated in accordance with U.S. GAAP. These non-GAAP measures include organic sales, organic operating income margin and adjusted diluted EPS. We provide these measures as additional information regarding our operating results. We use these non-GAAP measures internally to evaluate our performance and in making financial and operational decisions, including with respect to incentive compensation. We believe that our presentation of these measures provides investors with greater transparency with respect to our results of operations and that these measures are useful for period-to-period comparison of results.

These non-GAAP measures are not in accordance with, or an alternative to U.S. GAAP and may be different from non-GAAP measures used by other companies. You should not rely on any single financial measure when evaluating our business. We recommend that investors view these measures in conjunction with the U.S. GAAP measures, and we have provided reconciliations of reported U.S. GAAP amounts to the non-GAAP amounts below.

VIEW MATERIALS &VOTEAs a.stockholder of Ecolab Inc you have. the option of voting the. shares electronically through the Internet or on the telephone or by mail. Votes submitted electronically over the Internet or by telephone must be received by 11.59 PM Eastern Time on May 6., 2026 for shares held directly and by 11 59 PM Eastern Time on May .4,.2026 for shares held in a Plan.M VOTE BY INTERNETs'l_÷.1" Before the Annual Meeting - Go to vvvvvv.proxyvote.com or scan the QR Barcode above.Have the 16-dig itcontrol num berthatis printed in the box marked bythe arrow lxxxx>000cx)oo(x)ooci available and follow prompts to vote the shares.DURING THE ANNUAL MEETING - Go to www.virtualshareholdermeeting.com/ECL2026. You may attend the meeting via the Internet, submit questions and vote during the meeting when the polls are open Have the 1.6-digit control number available that is printed in the hox marked by the arrow —)D000cxxxxxxxxxxxxl and follow the prompts to register for access to the virtual meetingand to vote the shares.tr.& VOTE BY PHONELa Call 1-800-690-6903 using any touch-tone telephone to transmit your voting instructions Have yourproxy card in hand when you call and then follow the instructions.VOTE BY MAILMark, sign and date your proxy card and return it in the postage-paid envelope we have provided or returnit to Vote Processing, do Broadridge, 51 Mercedes Way, Edgewood, NY 11717gla ELECTRONIC DEUVERY OF FUTURE PROXY MATERIALS e If you would like to reduce the costs incurred by our company in mailing proxy materials, you can consent to receiving all future proxy statements, proxy cards and annual reports electronically via e-mail or the Internet. To sign up for electronic delivery, please follow the instructions above to vote using the Internet and, when prompted, indicate that you agree to receive or access proxy materials electronically in future years.. TO VOTE, MARK BLOCKS BELOW IN BLUE OR BLACK INK AS FOLLOWS:V87904-P41893KEEP THIS PORTION FOR YOUR RECORDSTHIS PROXY CARD IS VALID ONLY WHEN SIGNED AND DATED.DETACH AND RETURN THIS PORTION ONLY

Important Notice Regarding the Availability of Proxy Materials:The Notice and Proxy Statement and Annual Report are available at vvvvvv.proxyvote.com.V IF YOU HAVE NOT VOTED VIA THE INTERNET OR TELEPHONE, FOLD ALONG THE PERFORATION, DETACH AND RETURN THE BOTTOM PORTION IN THE ENCLOSED ENVELOPE.V Proxy — Ecolab Inc. THIS PROXY IS SOLICITED ON BEHALF OF THE BOARD OF DIRECTORSECOLAB INC.ANNUAL MEETING OF STOCKHOLDERSMAY 7, 2026The undersigned hereby appoints Christophe Beck, Jandeen M. Boone and Youhao Dong, and each of them, with full power of substitution to each as proxies to represent the undersigned at the Annual Meeting of Stockholders of Ecolab Inc., to be held virtually at vvvvw.virtualshareholdermeeting.condECL2026 at 9:30 a.m. Central Time on Thursday, May 7, 2026, and at any adjournment or postponement thereof, and to vote all shares of stock which the undersigned may be entitled to vote at said meeting as directed on the reverse side with respect to the proposals as set forth in the Proxy Statement, and in their discretion, upon any other matters that may properly come before the meeting.This proxy will be voted as specified by the undersigned. If no such direction is given, your proxies will have the authority to vote "FOR" each of the nominees listed in proposal 1, "FOR" on proposals 2 and 3, "AGAINST" on proposal 4 and in the discretion of the proxy holder on any other matter that may properly come before the annual meeting and any adjournment or postponement thereof.The tabulator cannot vote the shares unless you sign and return this card, or you use the telephone or Internet voting services to cast your proxy.Continued and to be signed on reverse side