8-K

UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

______________________

FORM 8-K

CURRENT REPORT

Pursuant to Section 13 or 15(d) of the

Securities Exchange Act of 1934

Date of report (Date of earliest event reported): September 18, 2012

Sigma-Aldrich Corporation

(Exact Name of Registrant as Specified in Charter)

Delaware	000-08135	43-1050617
(State or Other Jurisdiction of Incorporation)	(Commission File Number)	(IRS Employer Identification No.)

3050 Spruce Street, St. Louis, Missouri 63103

(Address of Principal Executive Offices, Including Zip Code)

Registrant’s telephone number, including area code: (314) 771-5765

N/A

(Former Name or Former Address, if Changed Since Last Report)

Check the appropriate box below if the Form 8-K filing is intended to simultaneously satisfy the filing obligations of the registrant under any of the following provisions (see General Instruction A.2.):

o    Written communications pursuant to Rule 425 under the Securities Act (17 CFR 230.425)

o    Soliciting material pursuant to Rule 14a-12 under the Exchange Act (17 CFR 240.14a-12)

o    Pre-commencement communications pursuant to Rule 14d-2(b) under the Exchange Act (17 CFR 240.14d-2(b))

o    Pre-commencement communications pursuant to Rule 13e-4(c) under the Exchange Act (17 CFR 240.13e-4(c))

Section 5 - Corporate Governance and Management

Item 5.02Departure of Directors or Certain Officers; Election of Directors; Appointment of Certain Officers; Compensatory Arrangements of Certain Officers.

On September 18, 2012, the Sigma-Aldrich Corporation (the "Company") Board of Directors (the "Board") elected Michael Marberry as a Director of the Company. Mr. Marberry (age 54) is the President and Chief Executive Officer of J.M. Huber Corporation, a diversified, multinational supplier of engineered materials, natural resources and technology-based services to customers spanning many industries from paper and energy to plastics and construction.

The Board has determined Mr. Marberry qualifies as an independent Director under Nasdaq Global Select Market rules and the Board's independence criteria set forth in the Company's Corporate Governance Guidelines. Mr. Marberry is not expected to be appointed to any standing Board committee at this time.

There are no arrangements between Mr. Marberry and any other person pursuant to which Mr. Marberry was elected to serve as a Director. Since January 1, 2012, the Company is not aware of any transaction, proposed transaction or series of either, where the amount involved exceeds $120,000, in which the Company is or will be a participant and Mr. Marberry has or will have a direct or indirect material interest.

For his services on the Board, Mr. Marberry will receive the same compensation as other independent members of the Board. A description of such compensation was previously reported under the heading "Director Compensation" on pages 12-14 of the Company’s Definitive Proxy Statement on Schedule 14A dated March 12, 2012, for the Company’s Annual Meeting of Shareholders held on May 1, 2012.

The press release announcing Mr. Marberry's election to the Board is furnished as Exhibit 99.1 to this Current Report on Form 8-K and is incorporated herein by reference.

Section 9 - Financial Statements and Exhibits

Item 9.01 Financial Statements and Exhibits.

Exhibit No.	Description
99.1	Text of press release dated September 19, 2012.

SIGNATURES

Pursuant to the requirements of the Securities Exchange Act of 1934, the registrant has duly caused this report to be signed on its behalf by the undersigned hereunto duly authorized.

		SIGMA-ALDRICH CORPORATION
Date:	September 19, 2012	By	/s/ George L. Miller
			George L. Miller Senior Vice President, General Counsel and Secretary

Exhibit Index

Exhibit No.	Description
99.1	Text of press release dated September 19, 2012.

EX-99.1

3050 Spruce Street, St. Louis, MO 63103 USA

Tel: (800) 521-8956 (314) 771-5765 Fax: (800) 325-5052 (314) 771-5757

News Release

FORWARD INQUIRIES TO:

Quintin Lai

Sigma-Aldrich Corporation

314-898-4643

quintin.lai@sial.com

FOR IMMEDIATE RELEASE

SIGMA-ALDRICH ELECTS MICHAEL MARBERRY AS DIRECTOR

St. Louis, MO, September 19, 2012 – The Board of Directors of Sigma-Aldrich Corporation (NASDAQ: SIAL) has elected Michael Marberry as a Director of the Company. Mr. Marberry (age 54) is President and CEO of J.M. Huber Corporation, a diversified, multinational supplier of engineered materials, natural resources and technology-based services to customers spanning many industries from paper and energy to plastics and construction.

In announcing Mr. Marberry’s election to the Board, Rakesh Sachdev, President and CEO of Sigma-Aldrich said, “We are extremely pleased to have Michael Marberry join our Board. His broad background and international experience in leading a successful global company and in expanding into applied chemical and industrial markets will help Sigma-Aldrich in strategic efforts to enhance its leadership position in Life Science and High Technology.”

About Sigma-Aldrich: Sigma-Aldrich is a leading Life Science and High Technology company. Its biochemical and organic chemical products and kits are used in scientific and genomic research, biotechnology, pharmaceutical development, the diagnosis of disease and as key components in pharmaceutical and other high technology manufacturing. The Company has customers in life science companies, university and government institutions, hospitals and in industry. Over one million scientists and technologists use its products. Sigma-Aldrich operates in 38 countries and has 9,100 employees providing excellent service worldwide. The Company is committed to accelerating customer success through innovation and leadership in Life Science, High Technology and Service. For more information about Sigma-Aldrich, please visit its award winning web site at www.sigma-aldrich.com.