POWER OF ATTORNEY

        Known by all those present, that Sherry Duff hereby constitutes and
appoints each of Joshua Horenstein, Michael Lestino and Han Kieftenbeld as her
true and lawful attorneys-in-fact with respect to Innophos Holdings, Inc. to:

        (1) execute for and on behalf of the undersigned, Forms 3, 4 and 5 in
        accordance with 16(a) of the Securities Exchange Act of 1934, as
        amended, and the rules thereunder;

        (2) do and perform any and all acts for and on behalf of the undersigned
        which may be necessary or desirable to complete and execute any such
        Forms 3, 4, and 5, complete and execute any amendment or amendments
        thereto, and timely file such forms with the United States Securities
        and Exchange Commission and any stock exchange or similar authority; and

        (3) take any other action of any type whatsoever in connection with the
        foregoing which, in the opinion of such attorney-in-fact, may be of
        benefit to, in the best interest of, or legally required by, the
        undersigned, it being understood that the documents executed by such
        attorney-in-fact on behalf of the undersigned pursuant to this Power of
        Attorney shall be in such form and shall contain such terms and
        conditions as such attorney-in-fact may approve in such attorney-in-
        fact's discretion.

        The undersigned hereby grants to each such attorney-in-fact full power
and authority to do and perform any and every act and thing whatsoever
requisite, necessary, or proper to be done in the exercise of any of the rights
and powers herein granted, as fully to all intents and purposes as the
undersigned might or could do if personally present, with full power of
substitution or revocation, hereby ratifying and confirming all that such
attorney-in-fact, or such attorney-in-fact's designated substitute or
substitutes, shall lawfully do or cause to be done by virtue of this Power of
Attorney and the rights and powers herein granted. The undersigned acknowledges
that the foregoing attorneys-in-fact, in serving in such capacity at the request
of the undersigned, are not assuming any of the undersigned's responsibilities
to comply with Section 16 of the Securities Exchange Act of 1934, as amended,
and the rules thereunder.

        This Power of Attorney shall remain in full force and effect until
revoked by the undersigned in a signed writing delivered to the each foregoing
attorney-in-fact.

        IN WITNESS WHEREOF, the undersigned has caused this Power of Attorney to
be executed as of August 26, 2016.

                                        /s/ Sherry Duff
                                        ---------------
                                        Signature
                                        Name: Sherry Duff