A/H1N1 ('swine flu') Virus Potential Pandemic Update

St. Louis, MO – May 4, 2009 – Sigma-Aldrich^® has a thorough business continuity and recovery plan in place globally, and responding to pandemic illness is included in the many scenarios it contains. While Sigma-Aldrich has heightened its awareness and communication levels internally in response to the current global flu event, we have not needed to implement our plan. Our trade compliance and supply chain organizations are closely monitoring import, export, and sourcing channels. At this point, we are not aware of any restrictions by any country that affect our products or our manufacturing.