X0306 4 2020-04-30 0 0000031462 ECOLAB INC. ECL 0001540754 Mulhere Timothy P 1 ECOLAB PLACE SAINT PAUL MN 55102 0 1 0 0 EVP & Pres - Global Inst Common Stock 2020-04-30 4 M 0 5112 55.595 A 21884.393 D Common Stock 2020-04-30 4 S 0 5112 195.036 D 16772.393 D Common Stock 1890.044 I By Ecolab Savings Plan Employee Stock Option (Right to Buy) 55.595 2020-04-30 4 M 0 5112 0 D 2012-12-01 2021-12-01 Common Stock 5112 7388 D This transaction was executed in multiple trades at prices ranging from $195.00 to $195.26, inclusive. The price reported above reflects the weighted average sale price. The reporting person hereby undertakes to provide upon request to the SEC staff, the issuer or a security holder of the issuer full information regarding the number of shares and prices at which the transaction was effected. Number of UNITS in the Ecolab Stock Fund of the Ecolab Savings Plan (401(k) Plan) as of March 31, 2020. Includes 7.369 UNITS acquired since the reporting person's last report.(The 1,890.044 UNITS are the equivalent of approximately 3,472 SHARES of the issuer's Common Stock.) The option became exercisable, on a cumulative basis, as to one-third of the option shares (excluding any fractional portion less than one share), on each of the first and second anniversaries of the date of grant and as to the remaining shares on the third anniversary of the date of grant. The date reflected in the Date Exercisable column is the first anniversary of the date of grant. /s/ David F. Duvick, as Attorney-in-Fact for Timothy P. Mulhere 2020-05-04