ECOLAB INC. — Director's Dealing 2015

May 7, 2015

SEC Form 4 — Statement of Changes in Beneficial Ownership

Issuer: ECOLAB INC (ECL)
CIK: 0000031462
Period of Report: 2015-05-05

Reporting Person: Hughes Bryan L (Sr. VP & Corporate Controller)

Non-Derivative Transactions

Date	Security	Code	Shares	Price	A/D	Holdings After	Ownership
2015-05-05	Common Stock	M	2035	$45.24	Acquired	6324	Direct
2015-05-05	Common Stock	S	1633	$112.2139	Disposed	4691	Direct

Derivative Transactions

Date	Security	Exercise Price	Code	Shares	A/D	Expiration	Underlying	Ownership
2015-05-05	Employee Stock Option (Right to Buy)	$45.24	M	2035	Disposed	2016-12-06	Common Stock (2035)	Direct

Holdings (Non-Derivative)

Security	Shares	Ownership
Common Stock	524.910	Indirect

Footnotes

F1: This transaction was executed in multiple trades at prices ranging from $112.186 to $112.258. 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.

F2: Number of UNITS in the Ecolab Stock Fund of the Ecolab Savings Plan (401(k) Plan) as of April 30, 2015. Includes 1.449 UNITS acquired since the reporting person's last report. (The 524.910 UNITS are the equivalent of approximately 969 SHARES of the issuer's Common Stock.)

F3: Option granted under the Ecolab Inc. 2002 Stock Incentive Plan on December 6, 2006. 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.