FIRST AMENDMENT TO RIGHTS AGREEMENT

Exhibit 4.1

FIRST AMENDMENT TO RIGHTS AGREEMENT

AMENDMENT (the “Amendment”), dated as of February 29, 2012, to the Rights Agreement, dated as of June 12, 2009 (the “Rights Agreement”), between Innospec Inc., a Delaware corporation (the “Company”), and Computershare Trust Company, N.A., as Rights Agent (the “Rights Agent”).

RECITALS

WHEREAS, the Company and the Rights Agent have heretofore executed and entered into the Rights Agreement.

WHEREAS, pursuant to Section 27 of the Rights Agreement, the Company may, and the Rights Agent shall if the Company so directs, from time to time supplement and amend the Rights Agreement.

WHEREAS, the Board of Directors of the Company has determined that an amendment to the Rights Agreement as set forth herein is necessary and desirable.

Accordingly, the parties agree as follows:

1. Amendment of Final Expiration Date. The definition of “Final Expiration Date” set forth in Section 1 of the Rights Agreement is hereby amended to read in its entirety as follows:

“Final Expiration Date” shall mean the close of business on March 1, 2012.

In addition, the references to June 26, 2014 on the Form of Rights Certificate attached as Exhibit B to the Rights Agreement are amended to read as March 1, 2012.

2. Effectiveness. This Amendment shall be deemed effective as of the date first written above, as if executed on such date. Except as amended hereby, the Rights Agreement shall remain in full force and effect and shall be otherwise unaffected hereby.

3. Miscellaneous. This Amendment shall be deemed to be a contract under the laws of the State of Delaware and for all purposes shall be governed and construed in accordance with the laws of such state applicable to contracts to be made and performed entirely within such state. If any provision, covenant or restriction of this Amendment is held by a court of competent jurisdiction or other authority to be invalid, illegal or unenforceable, the remainder of the terms, provisions, covenants and restrictions of this Amendment shall remain in full force and effect and shall in no way be effected, impaired or invalidated. Except as otherwise expressly provided herein, or unless the context otherwise requires, all terms used herein have the meanings assigned to them in the Rights Agreement. The Rights Agent and the Company hereby waive any notice requirement under the Rights Agreement pertaining to the matters covered by this Amendment. This Amendment may be executed in any number of counterparts and each of such counterparts shall for all purposes be deemed to be an original, and all such counterparts shall together constitute but one and the same instrument. A signature to this Amendment transmitted electronically shall have the same authority, effect, and enforceability as an original signature.

IN WITNESS WHEREOF, the parties hereto have caused this Amendment to be duly executed as of the day and year first above written.