ECOLAB INC. — Director's Dealing 2012

May 25, 2012

SEC Form 4 — Statement of Changes in Beneficial Ownership

Issuer: ECOLAB INC (ECL)
CIK: 0000031462
Period of Report: 2012-05-24

Reporting Person: BAKER DOUGLAS M JR (Director, Chairman and CEO)

Non-Derivative Transactions

Date	Security	Code	Shares	Price	A/D	Holdings After	Ownership
2012-05-24	Common Stock	M	314000	$34.50	Acquired	427847.583	Direct
2012-05-24	Common Stock	F	229295	$65.19	Disposed	198552.583	Direct
2012-05-24	Common Stock	M	37034	$43.24	Acquired	235586.583	Direct
2012-05-24	Common Stock	F	29888	$65.19	Disposed	205698.583	Direct
2012-05-24	Common Stock	M	59544	$51.445	Acquired	265242.583	Direct
2012-05-24	Common Stock	F	52349	$65.19	Disposed	212893.583	Direct
2012-05-24	Common Stock	M	61885	$46.715	Acquired	274778.583	Direct
2012-05-24	Common Stock	F	51834	$65.19	Disposed	223623.895	Direct

Derivative Transactions

Date	Security	Exercise Price	Code	Shares	A/D	Expiration	Underlying	Ownership
2012-05-24	Employee Stock Option (Right to Buy)	$34.50	M	314000	Disposed	2014-12-09	Common Stock (314000)	Direct
2012-05-24	Employee Stock Option (Right to Buy)	$43.24	M	37034	Disposed	2012-12-05	Common Stock (37034)	Direct
2012-05-24	Employee Stock Option (Right to Buy)	$51.445	M	59544	Disposed	2012-12-05	Common Stock (59544)	Direct
2012-05-24	Employee Stock Option (Right to Buy)	$46.715	M	61885	Disposed	2012-12-05	Common Stock (61885)	Direct

Holdings (Non-Derivative)

Security	Shares	Ownership
Common Stock	96400	Indirect
Common Stock	5186.702	Indirect

Footnotes

F1: Reflects the reporting person's payment of the exercise price and witholding taxes for a stock option issued in accordance with Rule 16b-3 by delivering or withholding shares of Ecolab common stock.

F2: Includes 345.102 shares acquired on January 20, 2012 and 334.210 shares acquired on April 19, 2012 by dividend reinvestment under the Dividend Reinvestment Plan for shareholders of Ecolab sponsored by Computershare Trust Company, N.A.

F3: Number of UNITS in the Ecolab Stock Fund of the Ecolab Savings Plan (401(k) Plan) as of April 30, 2012. Includes 33.675 UNITS acquired since the reporting person's last report. (The 5,186.702 UNITS are the equivalent of approximtely 9,644 SHARES of the issuer's Common Stock.)

F4: Option granted under the Ecolab Inc. 2002 Stock Incentive Plan. 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.