<PAGE>

Exhibit 31.2


I, John E. Sharland, certify that:


1.   I have reviewed this report on Form 10-Q of LSB Corporation;


2.   Based on my knowledge, this report does not contain any untrue statement of
     a 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
     report;

3.   Based on my knowledge, the financial statements, and other financial
     information included in this 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 report;

4.   The registrant's other certifying officers 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 the registrant 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 the
          registrant, including its consolidated subsidiary, 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 the registrant's disclosure controls
          and procedures and presented in this report our conclusion about the
          effectiveness of the disclosure controls and procedures as of the end
          of the period covered in this report based on such evaluation and;

     c)   disclosed in this report any change in the registrant's internal
          control over financial reporting that occurred during the registrant's
          most recent fiscal quarter that has materially affected, or is
          reasonably likely to materially affect, the registrant's internal
          control over financial reporting and;

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

     a)   all significant deficiencies and material weaknesses in the design or
          operation of internal controls over financial reporting which are
          reasonably likely to adversely affect the registrant'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 the registrant's internal
          controls over financial reporting.


Date: May 14, 2004

                                       /s/ John E. Sharland
                                       -----------------------------------------
                                       John E. Sharland
                                       Senior Vice President
                                       Chief Financial Officer


                                       22