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: 2012-05-07

Reporting Person: Hickey Michael A (Ex.VP & Pres. Institutional)

Non-Derivative Transactions

Date	Security	Code	Shares	Price	A/D	Holdings After	Ownership
2012-05-07	Common Stock	M	20000	$24.34	Acquired	36617.979	Direct
2012-05-07	Common Stock	S	11500	$64.00	Disposed	25141.964	Direct

Derivative Transactions

Date	Security	Exercise Price	Code	Shares	A/D	Expiration	Underlying	Ownership
2012-05-07	Employee Stock Option (Right to Buy)	$24.34	M	20000	Disposed	2012-12-05	Common Stock (20000)	Direct

Holdings (Non-Derivative)

Security	Shares	Ownership
Common Stock	3698.245	Indirect

Footnotes

F1: Includes 12.185 shares acquired by reporting person on January 20, 2012 and 11.800 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.

F2: Number of UNITS in the Ecolab Stock Fund of the Ecolab Savings Plan (401(k) Plan) as of April 30, 2012. Includes 48.005 UNITS acquired since the reporting person's last report. (The 3,698.245 UNITS are the equivalent of approximtely 6,876 shares of the issuer's Common Stock.)

F3: 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.