Your Board of Directors Seeks Your Support: VOTE FOR THE DOWDUPONT MERGER The merger of DuPont and The Dow Chemical Company is an extraordinary opportunity to deliver long-term sustainable growth and value to DuPont stockholders. The combined company intends to subsequently separate into three independent, publicly traded companies(1) that are stronger, more competitive, more resilient and better equipped to deliver growth and long-term sustainable value for you, our valued stockholders, than either company could deliver on its own. MATERIAL SCIENCE Net Sales: ~$46B ~$10B ~$6B ~$10B ~$2B ~$5B ~$46B LONG-TERM, SUSTAINABLE VALUE FOR DUPONT STOCKHOLDERS Enhanced Platform for Growth: Three intended companies to benefit from scale, focused growth strategies, strong balance sheets and differentiated technologies Compelling Synergies: Minimum of $3B in cost synergies and potential for $1B in growth synergies Industry Leading R&D Platform: Continue to be a leading investor in market-driven innovation Superior Customer Proposition: Superior solutions, expanded choices and greater value 4 4 4 4 Note: Numbers may not sum due to rounding. (1) Subject to the receipt of approval by the DowDuPont board and any required regulatory approvals. (2) Based on Dow’s and DuPont’s Net Sales as reported in each company’s 2015 Form 10-K filing. (3) Adjusted Net Sales includes revenue attributable to Dow Corning Corporation’s Silicones businesses in 2015. DOWDUPONT AGRICULTURE Net Sales: ~$16B(2) SPECIALTY PRODUCTS Net Sales: ~$12B(2) (2) Adjusted Net Sales: ~$51B(3) + + Dow Electronic + Consumer Solutions: Materials Agricultural Sciences Performance Materials Electronics & Communications Nutrition & Health Industrial Biosciences Safety & Protection Performance Plastics Performance Materials & Chemicals Infrastructure Solutions Consumer Solutions: Consumer Care Dow Automotive Systems Dow Corning Silicones Agriculture

PLEASE VOTE FOR THE MERGER TODAY – IT’S EASY AND QUICK: Whether or not you plan to attend the July 20, 2016 Special Meeting of Stockholders, please vote “FOR” adoption of the merger agreement and related matters TODAY. YOU MAY VOTE IN ONE OF THREE WAYS: To vote by telephone or on-line, first locate the Control Number printed on your proxy card or voting instruction form. Then: IMPORTANT REMINDER: If you hold shares in different accounts, you will receive separate proxy cards or voting instruction cards for each such account. Please remember to vote with respect to each account in which you hold shares. Failing to vote your shares will have the same effect as a vote against the merger. IMPORTANT INFORMATION ABOUT THE TRANSACTION AND WHERE TO FIND IT In connection with the proposed transaction, DowDuPont Inc. (f/k/a Diamond-Orion HoldCo, Inc.) (“DowDuPont”) has filed with the Securities and Exchange Commission (“SEC”), and the SEC has declared effective on June 9, 2016, a registration statement on Form S-4 (File No. 333-209869) (as amended, the “Registration Statement”) that includes a joint proxy statement of The Dow Chemical Company (“Dow”) and E. I. du Pont de Nemours and Company (“DuPont”) and that also constitutes a prospectus of DowDuPont. Dow, DuPont and DowDuPont may also file other documents with the SEC regarding the proposed trans-action. This document is not a substitute for the joint proxy statement/prospectus or Registration Statement or any other document which Dow, DuPont or DowDuPont may file with the SEC. INVESTORS AND SECURITY HOLDERS OF DOW AND DUPONT ARE URGED TO READ THE REGISTRATION STATEMENT, THE JOINT PROXY STATEMENT/PROSPECTUS AND ANY OTHER RELEVANT DOCUMENTS THAT ARE FILED OR WILL BE FILED WITH THE SEC, AS WELL AS ANY AMENDMENTS OR SUPPLEMENTS TO THESE DOCUMENTS, CAREFULLY AND IN THEIR ENTIRETY BECAUSE THEY CONTAIN IMPORTANT INFORMATION ABOUT THE PROPOSED TRANSACTION AND RELATED MATTERS. Investors and security holders may obtain free copies of the Registration Statement, the joint proxy statement/prospectus and other documents filed with the SEC (when available) by Dow, DuPont and DowDuPont through the web site maintained by the SEC at www.sec.gov or by contacting the investor relations department of Dow or DuPont at the following: Dow 2030 Dow Center Midland, MI 48674 Attention: Investor Relations 1-989-636-1463 DuPont 974 Centre Road Wilmington, DE 19805 Attention: Investor Relations: 1-302-774-4994 PARTICIPANTS IN THE SOLICITATION Dow, DuPont, DowDuPont and their respective directors and executive officers may be deemed to be participants in the solicitation of proxies in respect of the proposed transaction. Information regarding Dow’s directors and executive officers, including a description of their direct interests, by security holdings or otherwise, is contained in Dow’s Form 10-K for the year ended December 31, 2015, its proxy statement filed on April 1, 2016 and the joint proxy statement/prospectus of Dow contained in the Registration Statement filed on June 7, 2016, which are filed with the SEC. Information regarding DuPont’s directors and executive officers, including a description of their direct interests, by security holdings or otherwise, is contained in DuPont’s Form 10-K for the year ended December 31, 2015, its proxy statement filed on March 18, 2016 and the joint proxy statement/prospectus of DuPont contained in the Registration Statement filed on June 7, 2016, which are filed with the SEC. A more complete description is available in the Registration Statement and the joint proxy statement/prospectus. NO OFFER OR SOLICITATION This communication is not intended to and shall not constitute an offer to sell or the solicitation of an offer to sell or the solicitation of an offer to buy any securities or a solicitation of any vote of approval, nor shall there be any sale of securities in any jurisdiction in which such offer, solicitation or sale would be unlawful prior to registration or qualification under the securities laws of any such jurisdiction. No offer of securities shall be made except by means of a prospectus meeting the requirements of Section 10 of the Securities Act of 1933, as amended. CAUTIONARY NOTES ON FORWARD LOOKING STATEMENTS This communication contains “forward-looking statements” within the meaning of the federal securities laws, including Section 27A of the Securities Act of 1933, as amended, and Section 21E of the Securities Exchange Act of 1934, as amended. In this context, forward-looking statements often address expected future business and financial performance and financial condition, and often contain words such as “expect,” “anticipate,” “intend,” “plan,” “believe,” “seek,” “see,” “will,” “would,” “target,” similar expressions, and variations or negatives of these words. Forward-looking statements by their nature address matters that are, to different degrees, uncertain, such as statements about the consummation of the proposed transaction and the anticipated benefits thereof. These and other forward-looking statements, including the failure to consummate the proposed transaction or to make or take any filing or other action required to consummate such transaction on a timely matter or at all, are not guarantees of future results and are subject to risks, uncertainties and assumptions that could cause actual results to differ materially from those expressed in any forward-looking statements. Important risk factors that may cause such a difference include, but are not limited to, (i) the completion of the proposed transaction on anticipated terms and timing, including obtaining shareholder and regulatory approvals, anticipated tax treatment, unforeseen liabilities, future capital expenditures, revenues, expenses, earnings, synergies, economic performance, indebtedness, financial condition, losses, future prospects, business and management strategies for the management, expansion and growth of the new combined company’s operations and other conditions to the completion of the merger, (ii) the ability of Dow and DuPont to integrate the business successfully and to achieve anticipated synergies, risks and costs and pursuit and/or implementation of the potential separations, including anticipated timing, any changes to the configuration of businesses included in the potential separation if implemented, (iii) the intended separation of the agriculture, material science and specialty products businesses of the combined company post-mergers in one or more tax efficient transactions on anticipated terms and timing, including a number of conditions which could delay, prevent or otherwise adversely affect the proposed transactions, including possible issues or delays in obtaining required regulatory approvals or clearances, disruptions in the financial markets or other potential barriers, (iv) potential litigation relating to the proposed transaction that could be instituted against Dow, DuPont or their respective directors, (v) the risk that disruptions from the proposed transaction will harm Dow’s or DuPont’s business, including current plans and operations, (vi) the ability of Dow or DuPont to retain and hire key personnel, (vii) potential adverse reactions or changes to business relationships resulting from the announcement or completion of the merger, (viii) uncertainty as to the long-term value of DowDuPont common stock, (ix) continued availability of capital and financing and rating agency actions, (x) legislative, regulatory and economic developments, (xi) potential business uncertainty, including changes to existing business relationships, during the pendency of the merger that could affect Dow’s and/or DuPont’s financial performance, (xii) certain restrictions during the pendency of the merger that may impact Dow’s or DuPont’s ability to pursue certain business opportunities or strategic transactions and (xiii) unpredictability and severity of catastrophic events, including, but not limited to, acts of terrorism or outbreak of war or hostilities, as well as management’s response to any of the aforementioned factors. These risks, as well as other risks associated with the proposed merger, are more fully discussed in the joint proxy statement/prospectus included in the Registration Statement filed with the SEC in connection with the proposed merger. While the list of factors presented here is, and the list of factors presented in the Registration Statement are, considered representative, no such list should be considered to be a complete statement of all potential risks and uncertainties. Unlisted factors may present significant additional obstacles to the realization of forward looking statements. Consequences of material differences in results as compared with those anticipated in the forward-looking statements could include, among other things, business disruption, operational problems, financial loss, legal liability to third parties and similar risks, any of which could have a material adverse effect on Dow’s or DuPont’s consolidated financial condition, results of operations, credit rating or liquidity. Neither Dow nor DuPont assumes any obligation to publicly provide revisions or updates to any forward looking statements, whether as a result of new information, future developments or otherwise, should circumstances change, except as otherwise required by securities and other applicable laws. YOUR VOTE IS IMPORTANT, NO MATTER HOW MANY OR HOW FEW SHARES YOU OWN If you have questions about how to vote your shares, or need additional assistance, please contact the firm assisting us in the solicitation of proxies: INNISFREE M&A INCORPORATED (877) 750-9501 (toll-free from the US and Canada) (412) 232-3651 (from other locations) PHONE To vote by telephone, just call the toll-free number listed on your proxy card or voting instruction form and follow the easy voice prompts provided. MAIL If you prefer to vote by mail, simply sign, date and return the enclosed proxy card in the postage-paid envelope provided. ONLINE To vote on-line, simply access the website indicated on your proxy card or voting instruction form and follow the easy directions provided.