**Exhibit 31.2**

**CERTIFICATION PURSUANT TO SECTION 302(a) OF THE  SARBANES-OXLEY ACT OF 2002**

| 1.                                                                                                                                                                                                                                                                                                                                                                                                   | I   have reviewed this quarterly report on Form 10-QSB of Northern Technologies   International Corporation;                                                                                                                                                                                                                                                                                                                                     |
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| 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;                                       |
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| 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;                                               |
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| 4.       The small business   issuer’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 small business issuer and have:                                                                                            |
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|                                                                                                                                                                                                                                                                                                                                                                                                 | (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; |
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|                                                                                                                                                                                                                                                                                                                                                                                                 | (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                                                                                         |
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|                                                                                                                                                                                                                                                                                                                                                                                                 | (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 current reported quarter that has   materially affected, or is reasonably likely to materially affect, the small business issuer’s internal control   over financial reporting; and                                  |
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| 5.       The small business   issuer’s other certifying officers and I have disclosed, based on our most   recent evaluation of internal controls 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 function): |
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|                                                                                                                                                                                                                                                                                                                                                                                                 | (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 small business issuer’s ability to record, process, summarize and   report financial information; and                                                                                                  |
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|                                                                                                                                                                                                                                                                                                                                                                                                 | (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 controls over   financial reporting.                                                                                                                                                                                                   |