Q3 2012 Results (all percentages are to comparable periods in 2011)

Q3 2012 reported sales increased 2% to $639 million. Sales grew organically by 2% with Research and Sigma-Aldrich Fine Chemicals (“SAFC”) organic sales growth of 1% and 5%, respectively. Acquisitions contributed 6% to sales growth. Changes in foreign currency exchange rates reduced otherwise reportable sales by 6%.

Q3 2012 reported diluted EPS was $0.92 compared to $0.95 in Q3 2011. Excluding restructuring costs, Q3 2012 adjusted diluted EPS was $0.94 compared to $0.96 in Q3 2011. Changes in foreign currency exchange rates versus the same period last year reduced adjusted Q3 2012 EPS by $0.11. Excluding this impact, adjusted EPS would have grown by 9% from the same period last year.

Q3 2012 had strong free cash flow generation of $122 million. YTD 2012 net cash provided by operating activities and free cash flow were $379 million and $290 million, respectively.

2012 Outlook (all percentages are compared to full year 2011 results)

Overall organic sales growth for the full year 2012 is expected to be about 3%, within our prior guidance of low-to-mid single digits. Research sales are expected to grow organically in the low single digits in Q4 2012. SAFC sales are expected to grow in the mid-to-high single digits in Q4 2012.

Acquisitions are expected to increase 2012 sales growth by approximately 6%.

At current rates, foreign currency exchange rate changes are expected to reduce otherwise reportable sales for the full year 2012 by approximately 3%.

Guidance for adjusted diluted 2012 EPS (excluding restructuring charges, one-time acquisition-related transaction costs, and any other special charges) remains unchanged at $3.80 to $3.90.

Net cash provided by operating activities and free cash flow is expected to exceed $525 million and $400 million, respectively, for 2012, and is the same as prior guidance.

CEO’s STATEMENT:

Commenting on third quarter 2012 performance, President and CEO Rakesh Sachdev said, “We were able to deliver $0.94 adjusted EPS, which includes an $0.11 EPS headwind for unfavorable year-over-year changes in foreign currency exchange rates, while generating 2% overall organic sales growth.

While we continue to experience soft demand in our Research business, our end markets have remained relatively stable from second quarter levels. We believe our recent initiatives, including new product launches and expansion in emerging markets, have set us up for improved performance in the coming quarters.

SAFC sales were below our expectations, and a reminder that this business can fluctuate quarter to quarter. Third quarter results were impacted by the timing of a few large orders, including a large industrial cell culture media order, which slipped into the fourth quarter. Despite strong double-digit volume growth of our LED chemical precursors from our new Taiwan Hitech facility, market pricing declined more than expected. Additionally, some of our LED customers made late-quarter changes to orders as they adjusted inventory levels. We were able to mitigate some of the margin impact arising from price declines through reduced raw material prices and enhanced efficiencies.

For the fourth quarter, we expect sequential improvement in organic sales growth for SAFC. We remain positive on the end market dynamics in our Bioscience and Custom Pharma businesses. In Hitech, we expect to deliver higher sequential volume growth, despite inventory management by a few of our customers.”

Sachdev concluded, “We continue to monitor end market dynamics and are confident in our ability to enact further cost reduction actions, if necessary. Other than increased Hitech pricing and demand fluctuations, our end markets have generally remained stable since the second quarter. We were very pleased with our cash flow generation in the third quarter. We reaffirm our full-year adjusted EPS guidance of $3.80 to $3.90 and free cash flow guidance of more than $400 million. We remain fully committed to our strategic initiatives to support future growth and remain positive on the foundation that we have been building for growth in 2013 and beyond.”

Q3 2012 RESULTS:

Reported third quarter 2012 sales were $639 million and increased 2% over third quarter 2011. Excluding changes in foreign currency exchange rates, which reduced otherwise reportable sales by 6%, and acquisitions, which increased sales by 6%, third quarter 2012 organic sales growth was 2%.

Third quarter Research organic sales growth was 1%, led by strong sales of Analytical products offset by a decline in sales of Chemistry products as a result of continued Pharma consolidation.

Third quarter SAFC organic sales growth was 5%, led by double-digit growth in the Custom Pharma manufacturing business, offset by timing issues in Bioscience and late-quarter order adjustments and pricing declines in Hitech. A reconciliation of reported to adjusted (organic) sales for the Company can be found on page 10.

Adjusted operating income margin in third quarter 2012 was 25.0% of sales compared to 26.0% of sales in third quarter 2011. Adjusted operating income excludes restructuring costs in both periods.

Excluding the impact of year-over-year foreign exchange rate changes and incremental amortization expense related to new acquisitions, adjusted third quarter 2012 operating margin would have been 27.5%, an improvement of 150 basis points from the third quarter 2011. Reported and adjusted operating income includes amortization of acquisition related intangibles of $7 million, or $0.04 earnings per diluted share, in third quarter 2012 compared to $3 million, or $0.02 earnings per diluted share, in third quarter 2011. A reconciliation of reported to adjusted operating income and margin is provided on page 11.

The effective tax rate for third quarter 2012 was 27.7% compared to 25.9% in third quarter 2011 and was 30.1% for the first nine months of 2012 compared to 27.4% for the same period in 2011. The effective tax rate for full year 2012 is now expected to be approximately 30%.

Free cash flow (defined on page 9) for the first nine months of 2012 was $290 million compared to $300 million in the same time period of 2011. Free cash flow in 2012 is lower than 2011 due primarily to greater capital spending related to new facilities. A reconciliation of net cash provided by operating activities to free cash flow is provided on page 11.

Other highlights include:

Worldwide sales of Research products through the Company’s e-commerce channels grew 4% organically in third quarter 2012.

Asia Pacific and Latin America continued to be the leading geographic region for sales growth with mid-single digit growth. Europe grew low-single digits, and North America was flat.

SAFC’s booked orders for future delivery at September 30, 2012 grew 4% over the level at September 30, 2011.

China Novartis Institutes for BioMedical Research named the Company as a “Top 10 Strategic Partner Supplier.”

2012 OUTLOOK:

Organic sales growth is expected to be 3% for the full year, which is within our prior guidance range of low-to-mid single digits. Significant factors in the sales outlook include:

Research Business: Research sales are expected to grow organically in the low single digits in the fourth quarter of 2012, similar to the growth achieved in the first nine months of 2012.

SAFC Business: SAFC sales are expected to grow organically in the mid-to-high single digits in the fourth quarter of 2012.

Changes in foreign currency exchange rates are expected to reduce otherwise reported full year 2012 sales growth by approximately 3% as compared to the prior year.

Recent acquisitions, including BioReliance and Research Organics, are expected to increase sales by approximately 6%.

Adjusted diluted EPS forecast for 2012 (excluding any restructuring charges, one-time transaction costs associated with acquisitions, and other special charges) is reaffirmed to be $3.80 to $3.90.

The effective tax rate for full year 2012 is expected to be approximately 30%.

Changes in foreign currency rates since our last guidance update are estimated to be a slight positive to our prior EPS guidance. This has been offset by a lower outlook for SAFC, resulting in no net impact to overall adjusted EPS guidance for the full year 2012.

The adjusted diluted EPS outlook for 2012 includes the amortization of intangibles associated with acquisitions. This amortization is expected to reduce 2012 EPS by $0.15 as compared to a $0.07 reduction in 2011 EPS and is expected to negatively impact otherwise reportable operating margin by approximately $26 million in 2012.

Free cash flow for 2012 is reaffirmed and is expected to exceed $400 million.

Net cash provided by operating activities is expected to exceed $525 million.

Capital expenditures are expected to be approximately $125 million, unchanged from previous outlook.

About Sigma-Aldrich: Sigma-Aldrich is a leading Life Science and High Technology company whose biochemical and organic chemical products, kits and services are used in scientific research, including genomic and proteomic research, biotechnology, pharmaceutical development, the diagnosis of disease and as key components in pharmaceutical, diagnostics and high technology manufacturing. Sigma-Aldrich customers include more than one million scientists and technologists in life science companies, university and government institutions, hospitals and industry. The Company operates in 38 countries and has approximately 9,000 employees whose objective is to provide 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 website, at www.sigma-aldrich.com.