SUMMARY ANNUAL REPORT

FOR HERCULES INCORPORATED SAVINGS AND INVESTMENT PLAN

This is a summary of the annual report for the Hercules Incorporated Savings and Investment Plan, EIN 51-0023450, Plan No. 020, for the period January 1, 2006 through December 31, 2006. The annual report has been filed with the Employee Benefits Security Administration, U.S. Department of Labor, as required under the Employee Retirement Income Security Act of 1974 (ERISA).

Basic Financial Statement

Benefits under the plan are provided through a trust fund. Plan expenses were $48,457,000. These expenses included $26,000 in administrative expenses, $46,034,000 in benefits paid to participants and beneficiaries, and $2,397,000 in other expenses. In addition to the expenses, $11,139,000 in assets were transferred from the Plan as a result of the sale of a 51% interest in FiberVisions Delaware Corporation, LLC during the year ended December 31, 2006. A total of 3,857 persons were participants in or beneficiaries of the plan at the end of the plan year, although not all of these persons had yet earned the right to receive benefits.

The value of plan assets, after subtracting liabilities of the plan, was $370,845,000 as of December 31, 2006, compared to $327,561,000 as of January 1, 2006. During the plan year the plan experienced and increase in its net assets of $43,284,000. This increase includes unrealized appreciation and depreciation in the value of plan assets; that is, the difference between the value of the plan's assets at the end of the year and the value of the assets at the beginning of the year or the cost of assets acquired during the year. The plan had total income of $102,880,000 including employer contributions of $18,757,000, employee contributions of $12,869,000, realized gains of $6,141,000 from the sale of assets, earnings from investments of $65,103,000, and other income of $10,000.

Your Rights To Additional Information

You have the right to receive a copy of the full annual report, or any part thereof, on request. The items listed below are included in that report:

1. an accountant's report;

2. financial information and information on payments to service providers;

3. assets held for investment; and

4. information regarding any common or collective trusts, pooled separate accounts, master trusts or 103-12 investment entities in which the plan participates.

To obtain a copy of the full annual report, or any part thereof, write or call Hercules Incorporated Attn: Pension Trust Department, 1313 North Market Street, Wilmington, DE 19894-0001, (302) 594-5000.

You also have the right to receive from the plan administrator, on request and for the cost of copying noted above, a statement of the assets and liabilities of the plan and accompanying notes, or a statement of income and expenses of the plan and accompanying notes, or both. If you request a copy of the full annual report from the plan administrator, these two statements and accompanying notes will be included as part of that report.

You also have the legally protected right to examine the annual report at the main office of the plan (Hercules Incorporated Attn: Pension Trust Department, 1313 North Market Street, Wilmington, DE 19894-0001) and at the U.S. Department of Labor in Washington, D.C., or to obtain a copy from the U.S. Department of Labor upon payment of copying costs. Requests to the Department should be addressed to: Public Disclosure Room, Room N1513, Employee Benefits Security Administration, U.S. Department of Labor, 200 Constitution Avenue, N.W., Washington, D.C. 20210.

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