<PAGE>

                                  Exhibit 31.2

                  CERTIFICATION OF PRINCIPAL ACCOUNTING OFFICER
            PURSUANT TO SECTION 302 OF THE SARBANES-OXLEY ACT OF 2002

I, Conrad Nagel, certify that:

     1. I have reviewed this quarterly report on Form 10-QSB of U.S. Microbics,
Inc.;

     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 small business
issuer as of, and for, the periods presented in this report;

     4. The small business issuer 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 the small business issuer 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 small
          business issuer, 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 the small business issuer'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 the small business issuer's
          internal control over financial reporting that occurred during the
          small business issuer's most recent fiscal quarter (the small business
          issuer's fourth fiscal quarter in the case of an annual report) that
          has materially affected, or is reasonably likely to materially affect,
          the small business issuer's internal control over financial reporting;
          and

     5. The small business issuer's other certifying officer and I have
disclosed, based on our most recent evaluation of internal control over
financial reporting, to the small business issuer's auditors and the audit
committee of the small business issuer'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 which are
          reasonably likely to adversely affect the small business issuer'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 small business
          issuer's internal control over financial reporting.

Date: May 16, 2005

                                         /s/ Conrad Nagel
                                         ---------------------------------
                                         Conrad Nagel
                                         Principal Accounting Officer


                                       24