Donaldson Company, Inc. (NYSE:DCI), today announced that it has been selected as a constituent in the 2012-2013 Ocean Tomo 300 ® Patent Index (OT300). This Index, which was launched in 2006, is based on the value of intellectual property (IP) and represents a diversified portfolio of 300 companies that own the most valuable patents relative to their book value. Donaldson is a recognized intellectual property leader with its innovative filtration technologies, such as Ultra-Web ® media, PowerCore ® filtration, and Synteq XP ™ media. Donaldson’s technology investments have resulted in over 500 active, issued, or pending patent families covering a broad spectrum of the Company’s global products and technology. “Donaldson has a longstanding history and global reputation as a filtration technology innovator,” said Bill Cook, Donaldson’s CEO. “For nearly 100 years, we have prided ourselves on developing breakthrough filtration technologies that meet our Customers’ increasing needs for industrial and engine filtration. Using technology, our products help improve people’s lives, enhance our Customers’ equipment performance, and protect our global environment. Our inclusion in the OT300 Index is an honor and affirms our commitment to increasing Shareholder value through innovation and technology development.” In addition to being selected to the OT300 Index, Donaldson was recently included in the Minneapolis/St. Paul Business Journal’s “Top 25 Index of Patent Holders.” For 2011, Donaldson was ranked 11 th, with 43 U.S. patents granted. “Being recognized as one of the top 25 patent holders in Minnesota is also a special honor as this state is the home of many highly innovative and IP-rich companies,” said Cook. “This recognition would not be possible without the thousands of Donaldson employees who are committed to advancing our technologies and products.” About Donaldson Company Donaldson is a leading worldwide provider of air and liquid filtration systems. We are a technology-driven Company committed to satisfying our Customers’ needs for filtration solutions through innovative research and development, application expertise, and global presence. Our approximately 13,000 employees contribute to the Company’s success by supporting our Customers at our more than 140 sales, manufacturing, and distribution locations around the world.