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|Exhibit 31.1
I, David Unger, certify that:
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|1. | I have reviewed this annual report on Form 10-K of MFRI, Inc.                                                                                                                                                                                                                                               
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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 registrant as of, and for, the periods presented in this report;                
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|4. | The registrant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

the registrant and we 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 registrant,

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 registrant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 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                                                                
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|5. | The registrants other certifying officer 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 the registrants board of directors (or persons performing the equivalent functions):
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| | 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 registrant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 registrants internal control over financial reporting.                                                                                                   

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|Date: April 29, 2005
      /s/ David Unger                                                                      
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|David UngerDirector, Chairman of the Board of Directors,and Chief Executive Officer(Principal Executive Officer)

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