HERCULES INCORPORATED

                                                                    EXHIBIT 99.6

                            CERTIFICATION PURSUANT TO
                             18 U.S.C. SECTION 1350,
                             AS ADOPTED PURSUANT TO
                  SECTION 906 OF THE SARBANES-OXLEY ACT OF 2002

      In connection with the Annual Report of Hercules Incorporated (the
"Company") on Form 10-K/A for the period ended December 31, 2002 as filed with
the Securities and Exchange Commission on the date hereof (the "Report"), I,
Fred G. Aanonsen, Vice President and Controller, certify, pursuant to 18 U.S.C.
Section 1350, as adopted pursuant to Section 906 of the Sarbanes-Oxley Act of
2002, that:

(1)   The Report fully complies with the requirements of Section 13(a) or 15(d)
      of the Securities Exchange Act of 1934; and


(2)   The information contained in the Report fairly presents, in all material
      respects, the financial condition and results of operations of the
      Company.


/s/ Fred G. Aanonsen
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Fred G. Aanonsen
Vice President and Controller
May 1, 2003