X0202 4 2007-02-16 0 0000090185 SIGMA ALDRICH CORP SIAL 0001210653 PORWOLL JOE 1001 WEST SAINT PAUL AVE MILWAUKEE WI 53233 0 0 0 1 President, Aldrich Chemical Common Stock, $1 Par Value 2007-01-02 4 J 0 4250 38.86 A 8500 D Stock Option, Right to Buy 41.62 2007-02-16 4 A 0 7500 41.62 A 2008-02-16 2017-02-16 Common Stock, $1 Par Value 7500 7500 D Stock Option, Right to Buy 13.438 1999-03-09 4 A 0 5000 13.438 A 2000-03-09 2009-03-09 Common Stock, $1 Par Value 5000 10000 D Stock Option, Right to Buy 18.25 2000-11-13 4 A 0 6000 18.25 A 2001-11-13 2010-11-13 Common Stock, $1 Par Value 6000 12000 D Stock Option, Right to Buy 25.315 2002-05-07 4 A 0 5000 25.315 A 2003-05-07 2012-05-07 Common Stock, $1 Par Value 5000 10000 D Stock Option, Right to Buy 25.86 2003-05-06 4 A 0 7500 25.86 A 2004-05-06 2013-05-06 Common Stock, $1 Par Value 7500 15000 D Stock Option, Right to Buy 28.66 2004-05-04 4 A 0 7500 28.66 A 2005-05-04 2014-05-04 Common Stock, $1 Par Value 7500 15000 D Stock Option, Right to Buy 28.825 2005-07-08 4 A 0 3750 28.825 A 2006-07-08 2015-07-08 Common Stock, $1 Par Value 3750 7500 D Stock Option, Right to Buy 34.03 2006-05-01 4 A 0 3750 34.03 A 2007-05-01 2016-05-01 Common Stock, $1 Par Value 3750 7500 D On January 2, 2007, the common stock of Sigma-Aldrich Corporation split 2:1, resulting in the reporting person's ownership of4,250 additional shares of common stock Employee stock option granted pursuant to the Sigma-Aldrich Corporation Long-Term Incentive Plan of 2003, amended 2006 in compliance with rule 16(b)-3 Shares granted vest for a period of 3 years as established in the Sigma-Aldrich Corporation 2003 Long-Term Incentive Plan This option was previously reported as covering 5,000 shares at an exercise price of $26.875 per share, but is being adjusted to reflect the 2:1 stock split that occurred on January 2, 2007 This option was previously reported as covering 6,000 shares at an exercise price of $36.50 per share, but is being adjusted to reflect the 2:1 stock split that occurred on January 2, 2007 This option was previously reported as covering 5,000 shares at an exercise price of $50.63 per share, but is being adjusted to reflect the 2:1 stock split that occurred on January 2, 2007 This option was previously reported as covering 7,500 shares at an exercise price of $51.72 per share, but is being adjusted to reflect the 2:1 stock split that occurred on January 2, 2007 This option was previously reported as covering 7,500 shares at an exercise price of $57.32 per share, but is being adjusted to reflect the 2:1 stock split that occurred on January 2, 2007 This option was previously reported as covering 3,750 shares at an exercise price of $57.65 per share, but is being adjusted to reflect the 2:1 stock split that occurred on January 2, 2007 This option was previously reported as covering 3,750 shares at an exercise price of $68.06 per share, but is being adjusted to reflect the 2:1 stock split that occurred on January 2, 2007 Debbie Bockius, Attorney in Fact 2007-02-20