Mark Cassidy Appointed Vice President of SAFC® Contract Manufacturing Services

St. Louis, MO and CPhI Paris, October 5, 2010 - SAFC®, a member of the Sigma-Aldrich® Group (NASDAQ: SIAL), today announced that Mark Cassidy has been appointed Vice President of SAFC’s Contract Manufacturing Services. Cassidy joined SAFC in January 2009 as Director of Global Sales and Marketing, responsible for SAFC's contract manufacturing sales worldwide, which encompassed small and large molecule capabilities. Cassidy was promoted to his new position on September 20, 2010, and is based at SAFC's Cambridge, UK, facility and reports to SAFC President, Gilles Cottier.

"Over the past two years, Mark has helped us strengthen our presence in the custom manufacturing space despite challenging market conditions," said Cottier. "As Vice President overseeing our contract manufacturing efforts, Mark will aim his considerable talents at developing and maximizing the market potential for SAFC's unique manufacturing capabilities and help us deliver on our promise to provide unique problem-solving solutions to global customers while expanding market share and profitability."

Prior to joining SAFC, Cassidy spent 18 years working for Dow Chemical, where he held various positions in sales, marketing and operations in the UK, Germany, Switzerland and United States. He also worked at Merck Sharp and Dohme as a Medicinal Chemist at their Neuroscience Research Centre, Harlow, UK. Cassidy earned a BSc (Hons) in Chemistry from Leeds University, UK and holds a Ph.D. in Chemistry from St. John’s College, Cambridge, UK.

About SAFC®: SAFC is the custom manufacturing and services business unit of Sigma-Aldrich Corporation. We are recognized as a top 10 global fine molecule supplier and trusted manufacturer of specialty chemicals and biologics for the life science and high technology industries. Utilizing global "Centers of Excellence" and dedicated manufacturing facilities, SAFC can resolve development and manufacturing challenges and accelerate the production of custom materials. Our rich portfolio includes high-purity inorganic materials for high technology applications, cell culture products, services for biopharmaceutical manufacturing and biochemical production, and complex, multi-step organic synthesis of APIs and key intermediates. For more information about SAFC, visit www.safcglobal.com.

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 research, including genomic and proteomic research, biotechnology, pharmaceutical development and as key components in pharmaceutical, diagnostic 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 40 countries and has 7,600 employees providing excellent service worldwide. Sigma-Aldrich 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.

SAFC and Sigma-Aldrich are registered trademarks Sigma-Aldrich Biotechnology L.P. and Sigma-Aldrich Co.