THE DOW CHEMICAL COMPANY Floating Rate Notes due 2011

Exhibit 4.3

UNLESS THIS CERTIFICATE IS PRESENTED BY AN AUTHORIZED REPRESENTATIVE OF THE DEPOSITORY TRUST COMPANY (55 WATER STREET, NEW YORK, NEW YORK) (THE “DEPOSITORY”) TO THE ISSUER OR ITS AGENT FOR REGISTRATION OF TRANSFER, EXCHANGE OR PAYMENT, AND ANY CERTIFICATE ISSUED IS REGISTERED IN THE NAME OF CEDE & CO., OR SUCH OTHER NAME AS REQUESTED BY AN AUTHORIZED REPRESENTATIVE OF THE DEPOSITORY TRUST COMPANY AND ANY PAYMENT IS MADE TO CEDE & CO., ANY TRANSFER, PLEDGE OR OTHER USE HEREOF FOR VALUE OR OTHERWISE BY OR TO ANY PERSON IS WRONGFUL SINCE THE REGISTERED OWNER HEREOF, CEDE & CO., HAS AN INTEREST HEREIN.

THE DOW CHEMICAL COMPANY

Floating Rate Notes due 2011

THE DOW CHEMICAL COMPANY, a Delaware corporation (herein called the “Company,” which term includes any successor corporation under the Indenture hereinafter referred to), for value received, hereby promises to pay to CEDE & CO., or registered assigns, the principal sum of [                    ] DOLLARS (US$[                    ]) on August 8, 2011, in such coin or currency of the United States of America as at the time of payment shall be legal tender for the payment of public and private debts, and to pay interest thereon quarterly on each February 8, May 8, August 8 and November 8 (each an “Interest Payment Date”), commencing November 8, 2009 and at maturity on said principal sum, in such coin or currency of the United States of America as at the time of payment shall be legal tender for the payment of public and private debts, at the rate specified on the reverse hereof, or as may be adjusted pursuant to the terms hereof, from the most recent Interest Payment Date next preceding the date of this Security to which interest has been paid, unless the date hereof is a date to which interest has been paid, in which case from the date of this Security, or unless no interest has been paid on this Security, in which case from August 7, 2009, until payment of said principal sum has been made or duly provided for. Payments of such principal and interest shall be made at the office or agency of the Company in Chicago, Illinois, which, subject to the right of the Company to vary or terminate the appointment of such agency, shall initially be at the principal office of The Bank of New York Mellon Trust Company, N.A., Two North LaSalle Street, Chicago, Illinois 60602; provided , that payment of interest may be made at the option of the Company by check mailed to the address of the person entitled thereto as such address shall appear on the Security register; provided , further that so long as CEDE & CO. or another nominee of the Depository is the registered owner of this Security payments of principal and interest will be made in immediately available funds through the Depository’s Same-Day Funds Settlement System. Notwithstanding the foregoing, if the date hereof is after a Record

Date (as defined below) and before the related Interest Payment Date, this Security shall bear interest from such related Interest Payment Date; provided , that if the Company shall default in the payment of interest due on such Interest Payment Date, then this Security shall bear interest from the next preceding Interest Payment Date, to which interest has been paid or, if no interest has been paid on this Security, from August 7, 2009. The interest payable on any Interest Payment Date will, subject to certain exceptions provided in the Indenture referred to on the reverse hereof, be paid to the person in whose name this Security is registered at the close of business on the fifteenth (15th) calendar day immediately preceding such Interest Payment Date (whether or not a Business Day) (each a “Record Date”), and the interest payable at maturity will be payable to the person to whom the principal hereof shall be payable.

Reference is made to the further provisions of this Security set forth on the reverse hereof. Such further provisions shall for all purposes have the same effect as though fully set forth at this place.

This Security shall not be valid or become obligatory for any purpose until the certificate of authentication hereon shall have been signed by the Trustee under the Indenture referred to on the reverse hereof.

[Signatures appear on next page]

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IN WITNESS WHEREOF, THE DOW CHEMICAL COMPANY has caused this instrument to be signed by facsimile by its duly authorized representative.

Dated: August 7, 2009

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TRUSTEE’S CERTIFICATE OF AUTHENTICATION

This is one of the Securities of the series designated herein referred to in the within-mentioned Indenture.

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THE DOW CHEMICAL COMPANY

Floating Rate Notes due 2011

Section 1. General . This Note is one of a duly authorized issue of securities of the Company (herein called the “Securities”), issued and to be issued in one or more series under an Indenture, dated as of May 1, 2008 (the “Indenture”), between The Dow Chemical Company (the “Company”) and The Bank of New York Mellon Trust Company, N.A., as trustee (herein called the “Trustee”, which term includes any successor trustee under the Indenture), to which Indenture and all indentures supplemental thereto reference is hereby made for a statement of the respective rights, limitations of rights, duties and immunities thereunder of the Company, the Trustee and the Holders of the Securities and of the terms upon which the Securities are, and are to be, authenticated and delivered. This Security is one of the Securities of the series designated on the face hereof.

Section 2. Interest Rate . The interest rate on this Security will be reset quarterly on February 8, May 8, August 8 and November 8 of each year, commencing November 8, 2009 (each, an “Interest Reset Date”). This Security will bear interest at a per annum rate equal to three-month LIBOR (as defined below) for the applicable Interest Reset Period or Initial Interest Period (each as defined below) plus 2.25% (225 basis points). The interest rate for the Initial Interest Period will be three-month LIBOR, determined as of August 5, 2009, plus 2.25% per annum. The “Initial Interest Period” is the period from August 7, 2009 to but excluding November 8, 2009. Thereafter, each “Interest Reset Period” will be the period from and including an Interest Reset Date to but excluding the immediately succeeding Interest Reset Date; provided that the final Interest Reset Period will be the period from and including the Interest Reset Date immediately preceding the maturity date of this Security to but excluding the maturity date.

If any Interest Reset Date would otherwise be a day that is not a Business Day (as defined below), the Interest Reset Date will be postponed to the immediately succeeding day that is a Business Day, except that if that Business Day is in the immediately succeeding calendar month, the Interest Reset Date will be the immediately preceding Business Day.

The interest rate in effect on each day will be (i) if that day is an Interest Reset Date, the interest rate determined as of the Interest Determination Date (as defined below) immediately preceding such Interest Reset Date or (ii) if that day is not an Interest Reset Date, the interest rate determined as of the Interest Determination Date immediately preceding the most recent Interest Reset Date or the original issue date, as the case may be.

The interest rate applicable to each Interest Reset Period commencing on the related Interest Reset Date, or the date of original issuance in the case of the Initial Interest Period, will be the rate determined as of the applicable Interest Determination Date. The “Interest Determination Date” will be the second London business day immediately preceding the date of original issuance, in the case of the initial Interest Reset Period, or thereafter the applicable Interest Reset Date.

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The Bank of New York Mellon Trust Company, N.A., or its successor appointed by the Company, will act as calculation agent. Three-month LIBOR will be determined by the calculation agent as of the applicable Interest Determination Date in accordance with the following provisions:

(i) LIBOR is the rate for deposits in U.S. dollars for the 3-month period which appears on Bloomberg Page BBAM1 (as defined below) at approximately 11:00 a.m., London time, on the applicable Interest Determination Date. “Bloomberg Page BBAM1” means the display designated on page “BBAM1” on the Bloomberg Service (or such other page as may replace the BBAM1 page on that service, any successor service or such other service or services as may be nominated by the British Bankers’ Association for the purpose of displaying London interbank offered rates for U.S. dollar deposits). If no rate appears on Bloomberg Page BBAM1, LIBOR for such Interest Determination Date will be determined in accordance with the provisions of paragraph (ii) below.

(ii) With respect to an Interest Determination Date on which no rate appears on Bloomberg Page BBAM1 as of approximately 11:00 a.m., London time, on such Interest Determination Date, the calculation agent shall request the principal London offices of each of four major reference banks (which may include affiliates of Banc of America Securities LLC, Citigroup Global Markets) in the London interbank market selected by the calculation agent (after consultation with the Company) to provide the calculation agent with a quotation of the rate at which deposits of U.S. dollars having a three-month maturity, commencing on the second London business day (as defined below) immediately following such Interest Determination Date, are offered by it to prime banks in the London interbank market as of approximately 11:00 a.m., London time, on such Interest Determination Date in a principal amount equal to an amount of not less than U.S. $1,000,000 that is representative for a single transaction in such market at such time. If at least two such quotations are provided, LIBOR for such Interest Determination Date will be the arithmetic mean of such quotations as calculated by the calculation agent. If fewer than two quotations are provided, LIBOR for such Interest Determination Date will be the arithmetic mean of the rates quoted as of approximately 11:00 a.m., New York City time, on such Interest Determination Date by three major banks (which may include affiliates of Banc of America Securities LLC, Citigroup Global Markets Inc., HSBC Securities (USA) Inc. and Morgan Stanley & Co. Incorporated) selected by the calculation agent (after consultation with the Company) for loans in U.S. dollars to leading European banks having a three-month maturity commencing on the second London business day immediately following such Interest Determination Date and in a principal amount equal to an amount of not less than U.S. $1,000,000 that is representative for a single transaction in such market at such time; provided, however, that if the banks selected as aforesaid by the calculation agent are not quoting such rates as mentioned in this sentence, LIBOR for such Interest Determination Date will be LIBOR determined with respect to the immediately preceding Interest Determination Date.

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All percentages resulting from any calculation of any interest rate for this Security will be rounded, if necessary, to the nearest one hundred thousandth of a percentage point, with five one-millionths of a percentage point rounded upward (e.g., 9.876545% (or .09876545) would be rounded to 9.87655% (or .0987655), and all dollar amounts will be rounded to the nearest cent, with one-half cent being rounded upward.

Promptly upon such determination, the calculation agent will notify the Company and the Trustee (if the calculation agent is not the Trustee) of the interest rate for the new Interest Reset Period.

All calculations made by the calculation agent for the purposes of calculating interest on this Security shall be conclusive and binding on the holders and the Company, absent manifest errors.

A business day with respect to the Securities means (i) any day, other than a Saturday or Sunday, that is neither a legal holiday nor a day on which banking institutions are authorized or required by law or regulation to close in The City of New York and (ii) that is also a “London business day” (as defined below). A “London business day” with respect to the Securities means a day on which dealings in deposits in U.S. dollars are transacted in the London interbank market.

Section 3. Interest Rate Adjustment . The interest rate payable on this Security shall be subject to adjustments from time to time if either Moody’s (as defined below) or S&P (as defined below) or, if either Moody’s or S&P ceases to rate the Securities or fails to make a rating of the Securities publicly available for reasons outside of the Company’s control, a “nationally recognized statistical rating organization” within the meaning of Rule 15c3-1(c)(2)(vi)(F) under the Exchange Act, selected by us as a replacement agency for Moody’s or S&P (a “substitute rating agency”) downgrades (or subsequently upgrades) the credit rating assigned to the Securities, in the manner described below.

If the rating from Moody’s (or any substitute rating agency thereof) of the Securities is decreased to a rating set forth in the immediately following table, the interest rate on this Security will increase such that it will equal the interest rate otherwise in effect (as determined pursuant to Section 2 above) plus the percentage set forth opposite the ratings from the table below:

If the rating from S&P (or any substitute rating agency thereof) of the Securities is decreased to a rating set forth in the immediately following table, the interest rate on this Security will increase such that it will equal the interest rate otherwise in effect (as determined pursuant to Section 2 above) plus the percentage set forth opposite the ratings from the table below:

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If at any time the interest rate on this Security has been adjusted upward and either Moody’s or S&P (or, in either case, a substitute rating agency thereof), as the case may be, subsequently increases its rating of the Securities to any of the threshold ratings set forth above, the interest rate on this Security will be decreased such that the interest rate for this Security equals the interest rate otherwise in effect (as determined pursuant to Section 2 above) plus the perce