Hexion (HXOH) 10-K 2005 FY Annual report

EXHIBIT 31.1(a)

Certification of Financial Statements and Internal Controls

I, Craig O. Morrison, certify that:

1. I have reviewed this Annual Report on Form 10-K of Hexion Specialty Chemicals, Inc. (Hexion);

2. Based on my knowledge, this annual report does not contain any untrue statement of material fact or omit to state a material fact necessary to make the statements made, in light of the circumstances under which such statements were made, not misleading with respect to the period covered by this annual report;

3. Based on my knowledge, the financial statements, and other financial information included in this annual report, fairly present in all material respects the financial condition, results of operations and cash flows of the registrant as of, and for, the periods presented in this annual report;

4. Hexion’s other certifying officer and I are responsible for establishing and maintaining disclosure controls and procedures (as defined in Exchange Act Rules 13a-15(e) and 15d-15(e)) for Hexion and have:

a. Designed such disclosure controls and procedures, or caused such disclosure controls and procedures to be designed under our supervision, to ensure that material information relating to Hexion, including its consolidated subsidiaries, is made known to us by others within those entities, particularly during the period in which this report is being prepared;

b. Evaluated the effectiveness of Hexion’s disclosure controls and procedures and presented in this report our conclusions about the effectiveness of the disclosure controls and procedures, as of the end of the period covered by this report based on such evaluation; and

c. Disclosed in this report any change in Hexion’s internal control over financial reporting that occurred during Hexion’s most recent fiscal quarter (Hexion’s fourth fiscal quarter in the case of an annual report) that has materially affected, or is reasonably likely to materially affect, Hexion’s internal control over financial reporting; and

5. Hexion’s other certifying officer and I have disclosed, based on our most recent evaluation of internal control over financial reporting, to Hexion’s auditors and the audit committee of Hexion’s board of directors (or persons performing the equivalent functions):

a. All significant deficiencies and material weaknesses in the design or operation of internal control over financial reporting that are reasonably likely to adversely affect Hexion’s ability to record, process, summarize and report financial information; and

b. Any fraud, whether or not material, that involves management or other employees who have a significant role in Hexion’s internal control over financial reporting.

Date: March 16, 2006

/s/ Craig O. Morrison

Craig O. Morrison

Chief Executive Officer