ECOLAB INC. — Director's Dealing 2012

May 8, 2012

SEC Form 4 — Statement of Changes in Beneficial Ownership

Issuer: ECOLAB INC (ECL)
CIK: 0000031462
Period of Report: 2012-05-03

Reporting Person: Mulhere Timothy P (EVP & Pres. Gobal Healthcare)

Non-Derivative Transactions

Date	Security	Code	Shares	Price	A/D	Holdings After	Ownership
2012-05-03	Common Stock	M	10000	$27.39	Acquired	11508	Direct
2012-05-03	Common Stock	F	6722	$63.995	Disposed	4786	Direct
2012-05-03	Common Stock	M	10000	$27.39	Acquired	14786	Direct
2012-05-03	Common Stock	S	6400	$63.9701	Disposed	8386	Direct
2012-05-03	Common Stock	S	3600	$63.97	Disposed	4786	Direct

Derivative Transactions

Date	Security	Exercise Price	Code	Shares	A/D	Expiration	Underlying	Ownership
2012-05-03	Employee Stock Option (Right to Buy)	$27.39	M	10000	Disposed	2013-12-11	Common Stock (10000)	Direct
2012-05-03	Employee Stock Option	$27.39	M	10000	Disposed	2013-12-11	Common Stock (10000)	Direct

Holdings (Non-Derivative)

Security	Shares	Ownership
Common Stock	1634.098	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: Number of UNITS in the Ecolab Stock Fund of the Ecolab Savings Plan (401(k) Plan) as of April 30, 2012. Includes 34.608 UNITS acquired since the reporting person's last report. (The 1,634.098 UNITS are the equivalent of approximtely 3,038 shares of the issuer's Common Stock.)

F3: Option granted under the Ecolab Inc. 2002 Stock Incentive Plan on December 11, 2003. 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 option shares on the third anniversary of the date of grant.