Executive Change

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 ​ FORM 8-K/A ​ CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 ​ Date of Report (Date of earliest event reported)  February 18, 2025 ​ ECOLAB INC. (Exact name of registrant as specified in its charter) ​ ​ ​ ​ ​ ​ Delaware ​ 1-9328 ​ 41-0231510 (State or other jurisdiction of incorporation) ​ (Commission File No.) ​ (IRS Employer Identification No.) ​ ​ ​ ​ 1 Ecolab Place , Saint Paul , Minnesota 55102 (Address of principal executive offices) (Zip Code) ​ Registrant’s telephone number, including area code 1- 800 - 232-6522 (Not applicable) (Former name or former address, if changed since last report.) ​ Securities registered pursuant to Section 12(b) of the Act: ​ ​ ​ Title of each class      Trading symbol(s)      Name of each exchange on which registered Common Stock, $1.00 par value ​ ECL ​ New York Stock Exchange 2.625% Euro Notes due 2025 ​ ECL 25 ​ New York Stock Exchange ​ Check the appropriate box below if the Form 8-K filing is intended to simultaneously satisfy the filing obligation of the registrant under any of the following provisions (see General Instruction A.2. below): ​ ☐ Written communications pursuant to Rule 425 under the Securities Act (17 CFR 230.425) ​ ☐ Soliciting material pursuant to Rule 14a-12 under the Exchange Act (17 CFR 240.14a-12) ​ ☐ Pre-commencement communications pursuant to Rule 14d-2(b) under the Exchange Act (17 CFR 240.14d-2(b)) ​ ☐ Pre-commencement communications pursuant to Rule 13e-4(c) under the Exchange Act (17 CFR 240.13e-4(c)) ​ Indicate by check mark whether the registrant is an emerging growth company as defined in Rule 405 of the Securities Act of 1933 (§230.405 of this chapter) or Rule 12b-2 of the Securities Exchange Act of 1934 (§240.12b-2 of this chapter). Emerging growth company ☐ ​ If an emerging growth company, indicate by check mark if the registrant has elected not to use the extended transition period for complying with any new or revised financial accounting standards provided pursuant to Section 13(a) of the Exchange Act. ☐ ​ ​ ​ ​ ​ Item 5.02 Departure of Directors or Certain Officers; Election of Directors; Appointment of Certain Officers; Compensatory Arrangements of Certain Officers . ​ On February 20, 2025, Ecolab Inc. (the “Company”) filed a Current Report on Form 8-K (the “Initial 8   -   K”) disclosing that on February 20, 2025, the board of directors of the Company (the “Board”) had appointed Michel Doukeris as a member of the Board. At the time of the Initial 8-K, the Boad had not determined Mr. Doukeris’ committee assignments. ​ This Current Report on Form 8-K/A amends the Initial 8-K to disclose that, on May 7, 2025, the Board appointed Mr. Doukeris as a member of the Audit Committee and the Governance Committee of the Board, effective as of May 8, 2025. ​ ​ 2 ​ SIGNATURE ​ Pursuant to the requirements of the Securities Exchange Act of 1934, the registrant has duly caused this report to be signed on its behalf by the undersigned hereunto duly authorized. ​ ​ ​ ​ ​ ​ ​ ECOLAB INC. ​ ​ ​ ​ Date: May 9, 2025 By: /s/ Youhao Dong ​ ​ Youhao Dong ​ ​ Assistant Secretary ​ ​ ​ 3