X0306 4 2020-02-20 0 0000031462 ECOLAB INC. ECL 0001699917 McCormick Michael C. 1 ECOLAB PLACE SAINT PAUL MN 55102 0 1 0 0 EVP, GC & Secretary Common Stock 2020-02-20 4 M 0 4900 71.54 A 59430.162 D Common Stock 2020-02-20 4 S 0 2050 205.629 D 57380.162 D Common Stock 2020-02-20 4 S 0 1550 206.502 D 55830.162 D Common Stock 2020-02-20 4 S 0 1150 207.915 D 54680.162 D Common Stock 2020-02-20 4 S 0 150 208.523 D 54530.162 D Employee Stock Option (Right to Buy) 71.54 2020-02-20 4 M 0 4900 0 D 2013-12-05 2022-12-05 Common Stock 4900 0 D This transaction was executed in multiple trades at prices ranging from $205.130 to $206.120, 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. This transaction was executed in multiple trades at prices ranging from $206.140 to $207.090, 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. This transaction was executed in multiple trades at prices ranging from $207.455 to $208.440, 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. This transaction was executed in multiple trades at prices ranging from $208.490 to $208.590, 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. 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. /s/ David F. Duvick, as Attorney-in-Fact for Michael C. McCormick 2020-02-24