RUDNICK & WOLFE
                         

As filed with the Securities and Exchange Commission on December 15, 2006

Registration No. 333-_____ 

UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

WASHINGTON, D.C. 20549

FORM S-3

REGISTRATION STATEMENT UNDER

THE SECURITIES ACT OF 1933

MFRI, INC.

(Exact name of registrant as specified in its charter)

Delaware

36-3922969

(State or other jurisdiction of incorporation or organization)

(I.R.S. Employer Identification Number)

7720 Lehigh Avenue

Niles, Illinois 60714

(847) 966-1000

(Address, including zip code, and telephone number, including area code, of registrant’s principal executive offices)

Mr. David Unger

Chairman of the Board of Directors

MFRI, Inc.

7720 Lehigh Avenue

Niles, Illinois 60714

(847) 966-1000

(Name, address, including zip code, and telephone number, including area code, of agent for service)

Copy to:

Hal M. Brown, Esq.

DLA Piper US LLP

203 North LaSalle Street, Suite 1800 1900

Chicago, ILIllinois 60601 May 2, 1997

(312) 368-2109 VIA EDGAR368-4012

Approximate date of commencement of proposed sale to the public: From time to time after this registration statement becomes effective.

If the only securities being registered on this Form are being offered pursuant to dividend or interest reinvestment plans, please check the following box. [ ]

If any of the securities being registered on this Form are to be offered on a delayed or continuous basis pursuant to Rule 415 under the Securities Act of 1933, other than securities offered only in connection with dividend or interest reinvestment plans, check the following box. [ X ]

If this Form is filed to register additional securities for an offering pursuant to Rule 462(b) under the Securities Act, please check the following box and list the Securities Act registration statement number of the earlier effective registration statement for the same offering. [ ]

If this Form is a post-effective amendment filed pursuant to Rule 462(c) under the Securities Act, check the following box and list the Securities Act registration statement number of the earlier effective registration statement for the same offering. [ ]

If this Form is a registration statement pursuant to General Instruction I.D. or a post-effective amendment thereto that shall become effective upon filing with the Commission pursuant to Rule 462(e) under the Securities Act, check the following box. [ ]

If this Form is a post-effective amendment to a registration statement filed pursuant to General Instruction I.D. filed to register additional securities or additional classes of securities pursuant to Rule 413(b) under the Securities Act, check the following box. [ ]

CALCULATION OF REGISTRATION FEE

Title of each class
of securities to be registered

Amount to be registered

Proposed maximum offering price per unit(1)

Proposed maximum aggregate offering price (1)

Amount of registration
fee

Common Stock, par value, $0.01 per share

1,500,000 shs.

$22.02

$33,030,000

$3,535

(1)

Estimated solely for the purpose of computing the registration fee in accordance with Rule 457(c) based on the average of the high and low reported sales prices on the NASDAQ Global Market on December 11, 2006.

The Registrant hereby amends this Registration Statement on such date or dates as may be necessary to delay its effective date until the Registrant shall file a further amendment which specifically states that this Registration Statement shall thereafter become effective in accordance with Section 8(a) of the Securities Act of 1933 or until the Registration Statement shall become effective on such date as the Commission, acting pursuant to said Section 8(a), may determine.



The information in this prospectus is not complete and may be changed. We may not sell these securities until the registration statement relating to these securities has been declared effective by the Securities and Exchange Commission. This prospectus is neither an offer to sell nor a solicitation of an offer to buy these securities in any jurisdiction where such offer or sale is unlawful.

Subject to Completion

Dated _______, 2006

PROSPECTUS

1,500,000 Shares

MFRI, INC.

Common Stock

This prospectus relates to the offer and sale from time to time of 1,500,000 shares of common stock of MFRI, Inc., a Delaware corporation (the “Company”), par value $0.01 per share (“Common Shares”) by the Company.

The Common Shares are listed on the NASDAQ Global Market under the symbol “MFRI”.

Investing in our securities involves risk. Before buying our securities, you should read and consider the risk factors included in our periodic reports and in other information that we file with the Securities and Exchange Commission. See “Special Note Regarding Forward-Looking Statements.”

Neither the Securities and Exchange Commission 450 5th Street, N. W. Washington, D. C. 20549 Re: MFRI, INC. ANNUAL REPORT ON FORM 10-K FOR THE YEAR ENDED JANUARY 31, 1996 FILE NO. 0-18370 REGISTRATION STATEMENT ON FORM S-3 FILE NO. 333-21951 Ladies and Gentlemen: Attached, for filing,nor any state securities commission has approved or disapproved of these securities or passed upon the adequacy or accuracy of this prospectus. Any representation to the contrary is a conformed copycriminal offense.

The date of Amendment No. 1this prospectus is ___________, 200_.



TABLE OF CONTENTS

Page

SPECIAL NOTE REGARDING FORWARD-LOOKING STATEMENTS

3

AVAILABLE INFORMATION

3

INCORPORATION OF CERTAIN DOCUMENTS BY REFERENCE

3

THE COMPANY

4

USE OF PROCEEDS

4

PLAN OF DISTRIBUTION

4

EXPERTS

5

LEGAL MATTERS

5

No dealer, salesperson or other individual has been authorized to Registration Statement No. 333-21951 on Form S-3, including exhibits thereto, with respectgive any information or to shares of common stock, par value $. 01 per share, of MFRI, Inc. (the "Company"), that were issuedmake any representations not contained or incorporated by reference in this prospectus in connection with the mergeroffering covered by this prospectus. If given or made, such information or representations must not be relied upon as having been authorized by us. This prospectus does not constitute an offer to sell, or a solicitation of Midwesco, Inc. ("Midwesco") with and intoan offer to buy, the Company. The changesCommon Shares, in Amendment No. 1 include: (i) changesany jurisdiction where, or to any person to whom, it is unlawful to make any such offer or solicitation. Neither the delivery of this prospectus nor any offer or sale made in response to the staff's letter of comment dated March 20, 1997 (as discussed below); and (ii) minor editorial efforts and corrections. The responses herein are numbered consecutively to correspond to the commentshereunder shall, under any circumstances, create an implication that there has not been any change in the staff's letter. THE COMPANY, PAGE 3 1. The Company's Annual Report on Form 10-K forfacts set forth in this prospectus or in our affairs since the fiscal year ended January 31, 1997 ("1997 Form 10-K Report"), which isdate hereof.


SPECIAL NOTE REGARDING FORWARD-LOOKING STATEMENTS

Information contained in or incorporated by reference into this prospectus and any accompanying prospectus supplement contains “forward-looking statements” within the Registration Statement, includes a discussionmeaning of the business of Thermal Care. SELLING STOCKHOLDERS, PAGE 5 2. The Registration Statement has been revised as requested. 3. The Registration Statement has been revised as requested. PLAN OF DISTRIBUTION, PAGE 7 4. The Registration Statement has not been revised, in accordance with telephone conversations between the undersigned and Mr. Mark Webb of the staff. INFORMATION INCORPORATED BY REFERENCE, PAGE 7 5. The Registration Statement has been amended as requested. 6. As discussed by the undersigned and Mr. Webb, the Registration Statement incorporates the Company's Current Report on Form 8-K dated December 30, 1996, as required by Item 12 of Form S-3. However, no information incorporated therein has been incorporated by reference into the Registration Statement. EXPERTS 7. The Registration Statement has been revised to reflect the filing of the 1997 Form 10-K Report. See the responses to questions 10 and 11 below. INFORMATION INCORPORATED BY REFERENCE 8. The Registration Statement has been revised as requested. GENERAL 9. A consent for the use of the audit report contained in the 1997 Form 10-K Report has been included in the Registration Statement. 10. The Registration Statement has been amended to incorporate by reference the financial statements of the Company as of and for the year ended January 31, 1997 included in the 1997 Form 10-K Report. 11. The financial statements of the Company included in the 1997 Form 10-K Report include updated pro forma financial information with respect to the Company's December 30, 1996 acquisition of Midwesco. Midwesco merged with and into the Company and through such merger, Midwesco's accounts are included in the consolidated financial statements of the Company since the date of acquisition in accordance with APB No. 16. Management of the Company does not believe that the separate historic interim or prior year financial statements of Midwesco, after the consummation of the transaction and the merger of Midwesco into the Company, would be meaningful to the readers of its financial statements at this time. 12. Midwesco Management believes that, as a privately held entity, the "segmentation" provisions of APB 30 do not apply to Midwesco. The spin off of certain operations of Midwesco was contingent upon approval of the acquisition of Midwesco by the stockholders of the Company; thus, no "measurement date" under paragraph 14 of APB 30 had been reached. Management does not believe that restatement of Midwesco's historic interim or prior year financial statements, after the consummation of the transaction and the merger of Midwesco into the Company, would be meaningful to the readers of its financial statements at this time. 13. Because the fiscal 1994 consolidated statement of operations is not included in the 1997 Form 10-K Report, management does not believe it is meaningful at this point to amend the disclosure in the earlier year's Form 10-K. Management believes that the comparisons made in the referenced Form 10-K/A1 are meaningful given their pro forma nature. 14. The following reconciles the changes in the balance sheet accumulated depreciation and amortization to the cash flow provision for depreciation and amortization, for the year ended January 31, 1996 in $000's:
PATENTS AND PROPERTY, PLANT OTHER TOGETHER GOODWILL AND EQUIPMENT ASSETS Accum. Deprec/amort $158 $3,138 $-- $3,296 beginning Provision 289 983 63 1,335 Disposals (369) (369) Accum. Deprec/amort - - ending $447 $3,752 $63 $4,199
15. and 16. In the Company's financial statements for the fiscal year ended January 31, 1997, the first paragraph of Note 1 - Basis of Presentation, has been modified to make it clear that the Company became successor to Midwesco Filter Resources, Inc. through merger. The previous registrant was Midwesco Filter Resources, Inc. which is now a wholly-owned subsidiary of MFRI, Inc. ; the Company had no operations prior to its merger with Midwesco Filter Resources, Inc. 17. The Company adopted SFAS 121 in the fiscal year ended January 31, 1997. Note 2 - Significant Accounting Polices, to the Company's fiscal 1997 consolidated financial statements includes the disclosures required by this Statement, including a reference that since the adoption, no impairment losses have been recognized. 18. The debt referred to was repaid during the fiscal 1997. The language in Note 7 - Debt, did not make it clear that the waiver the Company received extended for more than one year. 19. The caption in Note 9 - Income Taxes has been revised to read "Accrued Commissions" not "Unearned Commissions." Management does not believe that this drafting change is material. 20. Note 12 (Note 3 in the Company's fiscal 1997 financial statements) - Related Party Transactions, has been reworded. 21. Amendment No. 1 to the Company's Annual Report on Form 10-K for the fiscal year ended January 31, 1996 (the "1996 Form 10-K Report") was filed in order to correct the following: 1. In the Consolidated Statements of Cash Flows "Prepaid expenses and other assets" for the year ended January 31, 1996 was changed from (1,285,000) to (1,151,000), with resulting totals changing accordingly. 2. In Notes to Consolidated Financial Statements Note 13, "Cash paid for interest" for the year ended January 31, 1996 was changed from 1,009,000 to 928,000. 3. In Notes to Consolidated Financial Statements Note 13, the Ricwil acquisition disclosures for the year ended January 31, 1995 were modified. Amendment No. 2 to the 1996 Form 10-K Report changes the third sentence under the caption "Liquidity and Capital Resources" of the Management's Discussion and Analysis of Financial Condition and Results of Operations section of the 1996 Form 10-K Report as follows: "This line of credit is unsecured, has a term of three years and provides for interest at the higher of the federal funds rate, in effect from time to time, plus 50 basis points and the bank's prime rate in effect from time to time." 22. and 23. The Company does not propose to amend its Form 8-K/A dated December 30, 1996. The Company believes that its amendment of the Registration Statement to incorporate by reference the Company's fiscal 1997 consolidated financial statements is sufficient to comply with Rule 3-01 and Rule 3-02 for Regulation S-X. See the responses to questions 10 and 11 above. 24. For the periods presented there were no contract claims for either the Company or Midwesco for which "realization [was] probable and the amount [was] reasonably estimable" (the Midwesco recognition policy) but for which "claims [were not yet] settled" (the MFRI recognition policy). Therefore, there was no difference in revenues measured in accordance with the two policies. Note that in the 1997 Form 10-K Report, the Company has reworded the description of its revenue recognition policy to more clearly describe its revenue recognition practices. 25. The Company is not awaiting additional information for any FAS 38 contingencies. Accordingly, the purchase price allocation is not considered to be preliminary. 26. The fair value of the MFRI common stock used to determine the purchase price has been changed to include a reasonable period before and after the Thermal Care Merger was announced. 27. Revenues, costs and expenses presented as those of Midwesco Businesses spun-off directly attributable to the transaction represent the revenue, costs and expenses of those businesses which the Company has no intention of pursuing, and which New Midwesco (as defined in the Company's Proxy Statement relating to the Special Meeting of Stockholders held on December 16, 1996) intended to continue (and has in fact continued uninterrupted since the time of the transaction). Those revenues, costs and expenses (including corporate general and administrative expenses) are factually supportable in that they have not been allocated but rather have been derived from the ledgers and related accounting records of Midwesco, in which its businesses have been separately accounted for. As a result of, and as a part of the transaction as planned at the time the Registration Statement was filed, Midwesco employees and resources adequate to support the general and administrative needs of Midwesco Businesses spun-off have been spun off to New Midwesco with those businesses. 28. The reconciliation requested is as follows, for the year ended January 31, 1996, in $000's: Income for operations: Heat transfer equipment, $2,231 page F-19 Note 10 Corporate administrative expenses to support this (759) business and being spun off with it Charge for unabsorbed costs of the leased building, to (154) be shared on an actual cost basis as provided by the Management Services Agreement Acquired Midwesco income from operations, page 48 $1,318 29. The Simtech subsidiary has operated at a loss and the minority stockholder has no obligation to fund such losses. 30. Midwesco's ownership percentage in MPJV (which ownership was spun off to New Midwesco in the transaction) was 55%. This special partnership completed in 1989 the construction project which was the sole purpose for its formation. Due to the dormant nature of this venture and its relative size, management of Midwesco elected not to fully consolidate its accounts. 31. The management of Midwesco and of MPJV's new owner, New Midwesco, believe recognition of contract revenue relating to claims is supported by SOP 81-1, as follows: a. The basis for the claims is a contractual performance guarantee for turbine performance, which was not met. b. The circumstances causing the additional costs were unforeseen at the contract date and the result of the turbine supplier's performance, not of MPJV's performance. c. Costs associated with the claim have been identified and measured and are reasonable in view of the work performed. d. The evidence supporting the claim is objective and verifiable. It consists of contractually guaranteed turbine performance to be measured by a contractually specified engineering formula, compared with the results of actual performance measured in accordance with that formula supervised, evaluated and attested to by competent third parties, including expert third parties who have testified during pretrial preparation and depositions. An offer to settle for an amount approximately the amount recognized on Midwesco's statements was once received from the turbine supplier but was rejected as inadequate. 32. Midwesco had deferred a portion (38%) of the gain on the sale of Perma-Pipe to the Company in order to match revenues with expenses in its consolidated financial statements. Immediately after selling Perma-Pipe to the Company, Midwesco owned approximately 38% of the stock of the Company. Therefore, Midwesco's gain resulted from a transaction with a 38%-owned affiliate and, subsequent to the sale of Perma-Pipe to the Company, Midwesco's financial statements included its 38% share of the earnings of the Company, which the Company's earnings were net of amortizing goodwill generated by the purchase of Perma-Pipe from Midwesco. By deferring 38% of the gain and amortizing it into income over the same period over which the Company was amortizing the Perma-Pipe goodwill, Midwesco matched the timing of its gain with the corresponding goodwill amortization expense of its 38%-owned affiliate in its financial statements. At the time of the acquisition of Midwesco by the Company, the 38% ownership was eliminated. * * * * * A manually signed and currently dated accountant's consent has been filed as Exhibit 23. 1 to the Registration Statement. Attached hereto, in accordance with Rule 461, is a letter from the Company to the Commission relating to acceleration of the effective date of the Registration Statement. We expect that the Company will submit an oral request for acceleration asking that the Registration Statement be ordered effective during mid-May. Accordingly, we would appreciate any further comments of the staff as soon as practicable. Please call the undersigned or Hal M. Brown (312/368-4012) of this law firm if there are any comments or questions concerning the enclosed Amendment No. 1. Very truly yours, RUDNICK & WOLFE /s/ Dorian R. Williams Dorian R. Williams DRW/ph Enclosures cc:Steven C. Duvall James Rosenberg Kevin Trolaro Mark S. Webb David Unger Michael D. Bennett Hal M. Brown MFRI, INC. 7720 Lehigh Avenue Niles, IL 60714 May 2, 1997 Securities and Exchange Commission 450 5th Street, N. W. Washington, D. C. 20549 Re: MFRI, INC. (THE "COMPANY") REGISTRATION STATEMENT ON FORM S-3 (REGISTRATION STATEMENT NO. 333-21951) Ladies and Gentlemen: Please be advised that the Company, at the appropriate time, intends to make an oral request that appropriate action be taken by the Commission under Section 8(a)27A of the Securities Act of 1933, as amended (the "Act"“Securities Act”),. We intend the forward-looking statements to orderbe covered by the above-captioned registration statement on Form S-3 (relatingsafe harbor provisions for forward-looking statements contained in that section. These forward-looking statements relate to, 2,124,298 shareswithout limitation, our anticipated future economic performance, our plans and objectives for future operations and projections of common stock) effective. The Company is awarerevenue and other financial items, which can be identified by the use of its obligations underforward-looking words such as “may,” “will,” “should,” “expect,” “anticipate,” “estimate” or “continue” or the Act. Very truly yours, /s/ Michael D. Bennett Michael D. Bennett Vice President AS FILED WITH THE SECURITIES AND EXCHANGE COMMISSION ON MAY 2, 1997. REGISTRATION NO. 333-21951 SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D. C. 20549 AMENDMENT NO. 1 to FORM S-3 REGISTRATION STATEMENT UNDER THE SECURITIES ACT OF 1933 MFRI, INC. (Exact name of registrant as specified in its charter) DELAWARE 36-3922969 (Statenegative thereof or other (IRS Employer jurisdiction Identification No.) of incorporationvariations thereon or organization) 7720 LEHIGH AVENUE NILES, ILLINOIS 60714 (847) 966-1000 (Address, including ZIP code, and telephone number, including area code, of registrant's principal executive offices) DAVID UNGER CHAIRMAN OF THE BOARD OF DIRECTORS MFRI, INC. 7720 LEHIGH AVENUE NILES, ILLINOIS 60714 (847) 966-1000 (Name, address, including ZIP Code, and telephone number, including area code, of agent for service) COPIES TO: HAL M. BROWN, ESQ. DORIAN R. WILLIAMS, ESQ. RUDNICK & WOLFE 203 NORTH LASALLE STREET, SUITE 1800 CHICAGO, ILLINOIS 60601 (312) 368-4000 (312) 236-7516(TELECOPIER) INFORMATION CONTAINED HEREIN IS SUBJECT TO COMPLETION OR AMENDMENT. A REGISTRATION STATEMENT RELATING TO THESE SECURITIES HAS BEEN FILED WITH THE SECURITIES AND EXCHANGE COMMISSION. THESE SECURITIES MAY NOT BE SOLD NOR MAY OFFERS TO BUY BE ACCEPTED PRIOR TO THE TIME THE REGISTRATION STATEMENT BECOMES EFFECTIVE. THIS PROSPECTUS SHALL NOT CONSTITUTE AN OFFER TO SELL OR THE SOLICITATION OF AN OFFER TO BUY NOR SHALL THERE BE ANY SALE OF THESE SECURITIES IN ANY STATE IN WHICH SUCH OFFER, SOLICITATION OR SALE WOULD BE UNLAWFUL PRIOR TO REGISTRATION OR QUALIFICATION UNDER THE SECURITIES LAWS OF ANY SUCH STATE. SUBJECT TO COMPLETION, DATED MAY 2, 1997 PROSPECTUS 2,124,298 Shares MFRI, INC. COMMON STOCK This Prospectus relates to 2,124,298 outstanding shares ("Shares") of common stock, par value $.01 per share (the "Common Stock"), of MFRI, Inc., a Delaware corporation (the "Company"), which may hereaf sold from time to time for the account of persons namedcomparable terms. The cautionary statements under the caption "Selling Stockholders." The Shares were issued“Risk Factors” contained in the merger (the "Merger") of Midwesco, Inc., an Illinois corporation, with and into the Company, which occurredour Annual Report on December 30, 1996 (the "Merger Closing Date"). The Shares may hereafter be offered or sold from time to timeForm 10-K for the account of persons named under the caption "Selling Stockholders" on the Nasdaq National Market,year ended January 31, 2006, which is incorporated herein by reference, and other similar statements contained in this prospectus or otherwise, at pricesany accompanying prospectus supplement identify important factors with respect to forward-looking statements, including certain risks and on terms then obtainable,uncertainties, that could cause actual results to differ materially from those in broker's transactions, special offerings, exchange distributions, negotiated transactions, block transactions, or otherwise. See "Selling Stockholders" and "Plan of Distribution." The Company will not realize any proceeds from any sale of the Shares. SEE "RISK FACTORS" ON PAGE 2 FOR A DISCUSSION OF CERTAIN FACTORS THAT SHOULD BE CONSIDERED BY PROSPECTIVE PURCHASERS OF THE COMMON STOCK OFFERED HEREBY. The Common Stock is traded on the Nasdaq National Market under the symbol MFRI. On May ____, 1997, the last reported sale price of the Common Stock on the Nasdaq National Market was $__________. ______________ THESE SECURITIES HAVE NOT BEEN APPROVED OR DISAPPROVED BY THE SECURITIES AND EXCHANGE COMMISSION OR ANY STATE SECURITIES COMMISSION NOR HAS THE COMMISSION PASSED OR ANY STATE SECURITIES COMMISSION UPON THE ACCURACY OR ADEQUACY OF THIS PROSPECTUS. ANY REPRESENTATION TO THE CONTRARY IS A CRIMINAL OFFENSE. ______________ MAY , 1997 NO DEALER, BROKER OR OTHER PERSON HAS BEEN AUTHORIZED TO GIVE ANY INFORMATION OR TO MAKE ANY REPRESENTATIONS, OTHER THAN THOSE CONTAINED IN THIS PROSPECTUS, IN CONNECTION WITH THE OFFERING MADE HEREBY, AND, IF GIVEN OR MADE, SUCH INFORMATION OR REPRESENTATION MUST NOT BE RELIED ON AS HAVING BEEN AUTHORIZED BY THE COMPANY. THIS PROSPECTUS DOES NOT CONSTITUTE AN OFFER TO SELL OR A SOLICITATION OF ANY OFFER TO BUY THE SECURITIES TO WHICH IT RELATES IN ANY JURISDICTION IN WHICH, OR TO ANY PERSON TO WHOM, IT IS UNLAWFUL TO MAKE SUCH AN OFFER OR SOLICITATION OF AN OFFER. NEITHER THE DELIVERY OF THIS PROSPECTUS NOR ANY OFFER OR SALE MADE HEREUNDER SHALL, UNDER ANY CIRCUMSTANCES, CREATE ANY IMPLICATION THAT THERE HAS BEEN NO CHANGE IN THE INFORMATION SET FORTH HEREIN OR IN THE AFFAIRS OF THE COMPANY SINCE THE DATE HEREOF. THIS PROSPECTUS, INCLUDING DOCUMENTS INCORPORATED BY REFERENCE, CONTAINS FORWARD-LOOKING STATEMENTS WITHIN THE MEANING OF SECTION 27A OF THE SECURITIES ACT AND SECTION 21E OF THE EXCHANGE ACT. FORWARD-LOOKING STATEMENTS ARE INHERENTLY SUBJECT TO RISKS AND UNCERTAINTIES, MANY OF WHICH CANNOT BE PREDICTED WITH ACCURACY AND SOME OF WHICH MIGHT NOT EVEN BE ANTICIPATED. FUTURE EVENTS AND ACTUAL RESULTS, FINANCIAL AND OTHERWISE, MAY DIFFER MATERIALLY FROM THE RESULTS DISCUSSED IN THE FORWARD-LOOKING STATEMENTS. FACTORS THAT MIGHT CAUSE SUCH A DIFFERENCE INCLUDE, BUT ARE NOT LIMITED TO, THOSE DISCUSSED IN "RISK FACTORS" HEREIN AND IN "MANAGEMENT'S DISCUSSION AND ANALYSIS OF RESULTS OF OPERATIONS AND FINANCIAL CONDITION" INCORPORATED BY REFERENCE IN THE COMPANY'S ANNUAL REPORT ON FORM 10-K FOR THE FISCAL YEAR ENDED JANUARY 31, 1997, WHICH IS INCORPORATED BY REFERENCE IN THIS PROSPECTUS. TABLE OF CONTENTS PAGE Available Information 2 Risk Factors 2 The Company 3 Selling Stockholders 5 Use of Proceeds 7 Plan of Distribution 7 Legal Matters 8 Experts 8 Information Incorporated By Reference 8 such forward-looking statements.

AVAILABLE INFORMATION The Company is

We are subject to the informational requirements of the Securities Exchange Act of 1934, as amended (the "Exchange Act"“Exchange Act”), and, in accordance therewith, files periodicwe are required to file reports, proxy statements and other information with the Securities and Exchange Commission (the "Commission"“Commission”). SuchYou may read and copy these reports, proxy statements and other information can be inspected and copied at the public reference facilities maintained by the Commission atPublic Reference Room 1024, 450 Fifth Street, N. W., Washington, D. C. 20549, and should also be available for inspection and copying at the regional offices of the Commission, located at 75 Park Place, 14th Floor, New York, New York 10007 and 500 West Madison100 F Street, Suite 1400, Chicago, Illinois 60661. Copies of such material can also be obtained from the Public Reference Section of the Commission at 450 Fifth Street, N. W.N.E., Washington, D. C. 20549 at prescribed rates. The Commission maintains a Web site that containsD.C. 20549. You may also obtain copies of the reports, proxy and information statements and other information aboutregarding issuers that file electronically with the Company. The address ofCommission by accessing the Commission's World Wide Web site maintained byat http://www.sec.gov. You may obtain information on the Commission is "http://www. sec. gov". This Prospectus constitutes a partoperation of a registration statement on Form S-3 (herein, together with all amendments and exhibits, the "Registration Statement") under the Securities Act of 1933, as amended (the "Securities Act"), filed by the Company. This Prospectus does not contain all of the information set forth in the Registration Statement. For further information, reference is hereby made to the Registration Statement, including the financial schedules and exhibits filed or incorporated by reference as a part thereof, which may be -examined at the Public Reference Room by calling the Commission at 1-800-SEC-0330.

INCORPORATION OF CERTAIN DOCUMENTS BY REFERENCE

We have filed the documents listed below with the Commission under the Exchange Act and these documents are incorporated into this prospectus by reference:

a.

Annual Report on Form 10-K for the year ended January 31, 2006.

b.

Quarterly Reports on Form 10-Q for the periods ended April 30, 2006, July 31, 2006, and October 31, 2006.

c.

Current Reports on Form 8-K filed on April 20, 2006, June 30, 2006, September 21, 2006, October 18, 2006, and November 6, 2006.

d.

Description of our common shares contained in the registration statement of our predecessor on Form 8-A filed on March 13, 1990.

All documents filed by us pursuant to Sections 13(a), 13(c), 14 and 15(d) of the CommissionExchange Act after the date of this prospectus and prior to the termination of the offering of all Common Shares under this prospectus will also be deemed to be incorporated by reference in Washington, D. C., without charge, or copies of which maythis prospectus and to be obtaineda part hereof from the Commission upon paymentdate of filing those documents.

Any statement contained in this prospectus or in a document incorporated or deemed to be incorporated by reference herein will be modified or superseded by inconsistent statements in any document we file in the prescribed fees. Statements containedfuture that will be deemed incorporated by reference herein, concerningincluding any prospectus supplement that supplements this prospectus. Any statement so modified or superseded shall not be deemed, except as so modified or superseded, to constitute a part of this prospectus or any accompanying prospectus supplement. Subject to the provisions of documents filed herewith as exhibits are necessarily summaries of such documents,foregoing, all information appearing in this prospectus and each such statementaccompanying prospectus supplement is qualified in its entirety by reference to the copy of the applicable document filed with the Commission. RISK FACTORS COMPETITION; BUSINESS. The businesses in which the Company is engaged are highly competitive. In addition, new installations of baghouses are subject to competition from alternative technologies and the sale of specialty piping systems and electronic leak detection and location systems are subject to competition from alternative products. The business of Thermal Care is dependent on the plastics industry. Any adverse trendsinformation appearing in the plastics industry may have a material adverse effect ondocuments incorporated by reference.

We will provide, without charge, copies of all documents that are incorporated herein by reference (not including the business of Thermal Care. Thermal Care relies upon a single source for key components of several of its products. Although the Company believes that thereexhibits to such information, unless such exhibits are alternate sources available for such components, there can be no assurance that the interruption of supplies of such components would not have an adverse effect on the financial condition of the Company, and that the Company, if required to do so, would be able to negotiate agreements with alternative sources on acceptable terms. GOVERNMENT REGULATION. The demand for the Company's leak detection and location systems and secondary containment piping systems is driven primarilyspecifically incorporated by government regulation with respect to hazardous waste. Laws such as the Federal Resource Conservation and Recovery Act ("RCRA"), and standards such as the National Emission Standard for Hydrocarbon Airborne Particulates ("NESHAP"), have increased the demand for the Company's leak detection and location and secondary containment piping systems. The Company's filtration products business to a large extent is dependent on governmental regulation of air pollution at the federal and state levels. The Company believes that continuing growth in the sale of filtration products and services will be materially dependent on continuing enforcement of environmental laws such as the Federal Clean Air Act Amendments of 1990 ("Clean Air Act Amendments"). Although changesreference in such environmental regulations could significantly alter the demand for the Company's products and services, the Company does not believe that such a changeinformation) to each person, including any beneficial owner, to whom this prospectus is likelydelivered upon written or oral request. Requests should be directed to decrease demand in the foreseeable future. ECONOMIC FACTORS. Although demand for many of the Company's products is generally affected by its customers' need to comply with governmental regulations, purchases of the Company's products at times may be delayed by customers due to adverse economic factors. DIVIDENDS. The Company has not paid dividends in the past and does not anticipate paying cash dividends on its common stock in the foreseeable future. The Company's line of credit agreement contains certain restrictions on payment of dividends. The primary restriction limits dividends to a cumulative amount of up to 25% of net income. LACK OF ARM'S-LENGTH NEGOTIATIONS; CONFLICTS OF INTEREST. The agreements between the Company and Midwesco relating to the Merger and the Perma-Pipe Transaction were not negotiated on an arm's-length basis. However, the Company believes the consideration, representations, warranties and covenants in such agreements are fair to the Company even though they may not provide the same level of protection as similar representations, warranties and covenants contained in comparable agreements with persons that are not affiliates of the Company. Members of the Board of Directors affiliated with Midwesco (Messrs. Unger, Ogilvie, Elgendy, Gruenberg and Henry and Bradley Mautner) will have a conflict of interest with respect to their obligations as directors and officers of the Company, and enforcingMFRI, Inc., 7720 Lehigh Avenue, Niles, Illinois 60714, Attention: Michael D. Bennett (telephone number: (847) 966-1000.)


Unless otherwise indicated, when used herein, the terms of such agreements against Midwesco, if necessary. "we, "us," and “our” refer to MFRI, Inc., a Delaware corporation, and its subsidiaries.

THE COMPANY The Company

MFRI, Inc., (“MFRI”), the (“Company” or the “Registrant”) is engaged in the manufacture and sale of filter bags for useproducts in industrial air pollution control systems known as "baghouses", and also engineers, designs and manufactures specialtythree distinct business segments: filtration products, piping systems and leak detection and location systems, and industrial waterprocess cooling equipment. The Company, which was incorporated in Delaware in October 1993, is the successor corporation to Midwesco Filter Resources, Inc. ("Midwesco Filter"). Midwesco Filter was incorporated in Delaware in October 1989 as a wholly owned subsidiary of Midwesco. On December 13, 1989, Midwesco Filter exchanged shares of its common stock for the net assets constituting its Midwesco Filter Resources division ("Filter Division") of Midwesco. The Filter Division was formed from certain assets of the Filter Media division of the Kennecott Corporation, acquired by Midwesco in June 1982, and certain assets of the Filter Resources Corporation, acquired by Midwesco in December 1983. On January 28, 1994 pursuant to a merger transaction ("Perma-Pipe Transaction") between the Company, a subsidiary of the Company and Midwesco Filter, the Company acquired the Perma-Pipe business ("Perma-Pipe") from Midwesco for cash and 278,666 shares of Common Stock. Pursuant to the Perma-Pipe Transaction, each share of common stock of Midwesco Filter was exchanged for one share of Common Stock. Immediately prior to the effective time of the Perma-Pipe Transaction, a public offering (the "Offering") of shares of common stock of Midwesco Filter was consummated, the net proceeds of which were used to repay bank debt related to Perma-Pipe. Perma-Pipe is in the business of engineering, designing and manufacturing specialty piping systems and leak detection and location systems. On September 30, 1994, the Company and an indirect wholly-owned subsidiary of the Company, pursuant to a purchase agreement dated as of such date ("Purchase Agreement"), acquired substantially all of the assets of Ricwil Piping Systems Limited Partnership ("Ricwil LP") for cash and 55,710 shares of Common Stock, as adjusted in accordance with the terms of the Purchase Agreement. Ricwil LP was a manufacturer of insulated piping systems for district heating and cooling systems. On December 6, 1995, Perma-Pipe acquired for cash the net assets and leak detection business of Hagenuk GmbH. On August 15, 1996, the Company, pursuant to an Asset Purchase Agreement dated as of such date (the "Purchase Agreement"), acquired substantially all of the assets of Eurotech Air Filtration, Inc., an Oregon corporation ("Eurotech"), for cash and 30,571 shares of Common Stock, subject to possible adjustments in accordance with the terms of the Purchase Agreement. Pursuant to the Purchase Agreement, Eurotech has the right, subject to certain conditions, to distribute such shares to its four shareholders. On December 30, 1996, the Company acquired the Thermal Care Division ("Thermal Care") and certain other specified assets and liabilities of Midwesco by the merger of Midwesco with and into MFRI (the "Merger"). Through the Merger, an aggregate of 2,124,298 shares of Common Stock were issued to the shareholders of Midwesco and the 1,717,666 shares of Common Stock owned by Midwesco immediately prior to the consummation of the Merger were cancelled. Thermal Care engineers, designs and manufactures industrial water cooling equipment. The Company's filtration products business is carried on by Midwesco Filter, and the piping system products business is carried on by Perma- Pipe, Inc. Midwesco Filter and Perma-Pipe, Inc. are wholly-owned subsidiaries of MFRI. As used herein, unless the context otherwise requires, the term Company“Company” includes MFRI Inc., Midwesco Filter, Thermal Care, Perma-Pipe, Inc., and its subsidiaries, Midwesco Filter Resources, Inc., Perma-Pipe, Inc., Thermal Care Inc., and their predecessors. respective predecessors and subsidiaries.

The Company's principalFiltration Products business segment manufactures and sells a wide variety of filter elements for air filtration and particulate collection systems. Air filtration systems are used in many industries in the United States and abroad to limit particulate emissions to comply with environmental regulations. The Filtration Products business segment markets air filtration-related products and accessories, and provides maintenance services, consisting primarily of dust collector inspection, filter cleaning and filter replacement.

The Piping Systems business segment engineers, designs, manufactures and sells specialty piping systems and leak detection and location systems. This segment’s specialty piping systems include (i) industrial and secondary containment piping systems for transporting chemicals, waste streams and petroleum liquids, (ii) insulated and jacketed district heating and cooking piping systems for efficient energy distribution to multiple locations from central energy plants, and (iii) oil and gas gathering flow lines and long lines for oil and mineral transportation. The Piping Systems business segment’s leak detection and location systems are sold as part of many of its piping systems products and on a stand-alone basis, to monitor areas where fluid intrusion may contaminate the environment, endanger personal safety, cause a fire hazard, impair essential services or damage equipment or property.

The Industrial Process Cooling Equipment business segment engineers, designs, manufactures and sells industrial process cooling equipment, including liquid chillers, mold temperature controllers, cooling towers, plan circulating systems, and related accessories for use in industrial process applications.

Our executive offices are located at 7720 Lehigh Avenue, Niles, Illinois, 60714 and itsour telephone number is (847) 966-1000. Other information concerning

USE OF PROCEEDS

Unless we otherwise specify in the Company's management,applicable prospectus supplement, the net proceeds received from the sale of the securities offered by this prospectus and any prospectus supplement will be used for general corporate purposes. General corporate purposes may include the repayment of debt, financing of possible acquisitions, business securities,expansion and resultsworking capital.

PLAN OF DISTRIBUTION

We may sell the shares of operations is incorporatedCommon Stock offered hereby to one or more underwriters for public offering and sale by reference from its reports filed withthem or may sell such shares to investors directly or through agents. Any underwriter or agent involved in the Commission. See "Information Incorporated by Reference." SELLING STOCKHOLDERS The Sharesoffer and sale of such shares will be named in the applicable prospectus supplement.

Underwriters may offer and sell such shares at a fixed price or prices, which may be offeredchanged, at prices related to the prevailing market prices at the time of sale or at negotiated prices. We may, from time to time, forauthorize underwriters acting as our agents to offer and sell such shares upon the account of the Selling Stockholders whose namesterms and conditions as are set forth in the table below. The table sets forth information as of January 31, 1997 with respect to the beneficial ownership of the Shares by the Selling Stockholders. To the knowledge of the Company, none of the Selling Stockholders has any material relationshipapplicable prospectus supplement. In connection with the Company except as set forthsale of such shares, underwriters may be deemed to have received compensation from us in the footnotesform of underwriting discounts or commissions and may also receive commissions from purchasers of such shares for whom they may act as agent. Underwriters may sell such shares to the following table and as more fully described elsewhere in this Prospectus (including the information incorporated by reference in this Prospectus).
NO. OF SHARES NO. OF SHARES NO. OF SHARES WHICH OWNED PRIOR TO WHICH MAY BE MAY BE OWNED AFTER SELLING STOCKHOLDER OFFERING(1) OFFERED OFFERING(1) Henry Mautner(2) 451,688 419,938 31,750 Debra Mautner 170,473 170,473 -- David M. Mautner(3) 171,298 170,473 825 Bradley E. Mautner(4) 172,773 170,473 2,300 David Unger(5) 535,677 489,927 45,750 Maxine S. Unger(6) 29,359 12,859 16,500 Judith Golden 141,632 141,632 -- Rebecca Fishman 148,932 141,632 7,300 Michael Unger 142,132 141,632 500 Robert F. Spreenberg(7)187,925 187,925 -- David A. Miller(8) 6,611 5,511 1,100 William F. Davis(9) 27,126 25,901 1,225 Judith & Jeff Golden 4,374 3,674 700 Don L. Gruenberg(10) 4,587 1,837 2,750 John F. Conroy(11) 2,543 918 1,625 Carlo Ferraro(12) 367 367 -- Edward A. Crylen(13) 3,062 1,837 1,225 Herbert J. Sturm(14) 9,815 3,490 6,325 Robert K. Spreenberg(15) 9,552 9,552 -- Gene K. Ogilvie(16) 43,772 11,022 32,750 Michael D. Bennett(17) 10,331 3,306 7,025 Fati Elgendy(18) 27,969 9,919 18,050
(1) Includes shares, if any, held by spouse; held as custodian; held in joint tenancy with spouse; held by or for the benefit of the named person or one or more members of his immediate family; with respect to which the named person has or shares voting or investment powers; or in which the named person otherwise has a beneficial interest. Also includes shares issuable upon exercise of employee stock options. (2) Henry Mautner is Director and Vice Chairman of the Board of Directors of the Company. From 1972 to the Merger Closing Date, he served as Chairman of Midwesco. (3) From June 1985 to the Merger Closing Date, David M. Mautner served as Director of Midwesco. (4) Bradley E. Mautner is Director and Vice President of the Company. From January 1994 to the Merger Closing Date, he served as President of Midwesco. In addition, since February 1996, he served as the Chief Executive Officer of Midwesco Services, Inc. ("Midwesco Services"), which, prior to the Merger Closing Date, was a 50% owned affiliate of Midwesco. Mr. Mautner served as President of Midwesco Services from February 1988 to January 1996. (5) David Unger is Director, Chairman of the Board of Directors, President and Chief Executive Officer of the Company. From 1972 to the Merger Closing Date, he served as Director of Midwesco, having served as President from 1972 to January 1994 and Vice President since January 1994. (6) From March 1993 to the Merger Closing Date, Maxine S. Unger served as Director of Midwesco. (7) From February 1970 to the Merger Closing Date, Robert K. Spreenberg served as Director and Executive Vice President of Midwesco. (8) From June 1979 to the Merger Closing Date, Mr. Miller served as Vice President of Midwesco. (9) From June 1979 to the Merger Closing Date, Mr. Davis served as Vice President of Midwesco. (10) Mr. Gruenberg is Director and Vice President of the Company. From August 1980 to the Merger Closing Date, he served as Vice President of Midwesco. (11) Mr. Conroy is Comptroller and Assistant Secretary of the Company. From January 1980 to the Merger Closing Date, he served as Controller of Midwesco. (12) From May 1982 to the Merger Closing Date, he served as Vice President of Midwesco Services. (13) From August 1982 to the Merger Closing Date, he served as Vice President of Midwesco. (14) Mr. Sturm is Vice President of the Company and of Midwesco Filter. (15) Robert K. Spreenberg is an employee of the Company. From May 1979 to the Merger Closing Date, he was employed by Midwesco. (16) Mr. Ogilvie is Director, Vice President of the Company and President of Midwesco Filter. From 1982 to the Merger Closing Date, he served as Vice President of Midwesco. (17) Mr. Bennett is Vice President, Secretary and Treasurer of the Company. From 1989 to the Merger Closing Date, he served as Vice President, Secretary and Treasurer of Midwesco. (18) Mr. Elgendy is Director, Vice President of the Company and President of Perma-Pipe, Inc. At March 31, 1997, there were 4,965,329 shares of Common Stock outstanding. USE OF PROCEEDS This Prospectus relates solely to Shares being offered and sold for the accounts of the Selling Stockholders. The Company will not realize any proceeds from any sale of Shares by the Selling Stockholders. PLAN OF DISTRIBUTION The Selling Stockholders may offer and sell Shares by means of the Prospectus from time to time in one or more transactions, directly by the Selling Stockholders, or through agents, dealers, or brokers to be designated from time to time;and such offers and sales may be effected over any national securities exchange or automated interdealer quotation system on which shares of the Common Stock are then listed, in negotiated transactions or in a combination of such methods of sale; the selling price of the Shares may be at market prices prevailing at the time of sale, at prices related to such prevailing market prices or at negotiated prices; and the Shares may also be offered in coordinated block transactions through underwriters, dealers or agents, or otherwise who may receive compensation in the form of underwriting or brokerage discounts, concessions or commissions from the Selling Stockholders underwriters and/or commissions from the purchasers of such Shares for whom they may act as agents. In certain states, the Selling Stockholders may be requiredagent.

Any underwriting compensation paid by us to offer and sell Shares only through brokers and dealers registered in such states. The Selling Stockholders and any brokersunderwriters or dealers that actagents in connection with the saleoffering of Shares hereunderthe shares of Common Stock offered hereby will be set forth in the applicable prospectus supplement. The prospectus supplement may further state that such underwriters may allow discounts, concessions or commissions to participating dealers. Underwriters, dealers and 


agents participating in the distribution of such shares may be deemed to be "underwriters" within the meaning of Section 2(11) of the Securities Actunderwriters, and any discounts and commissions received by them and any profit realized by them on the saleresale of Shares as principalsuch shares may be deemed to be underwriting discounts and commissions, under the Securities Act. The Company will pay all of the expenses of the preparation, printingUnderwriters, dealers and filing of the Registration Statement, any amendments or supplements thereto,agents may be entitled, under agreements entered into with us, to indemnification against and prospectuses and revised prospectuses as required to cover the transactions covered hereby, as well as the Company's fees and disbursements of its counsel and accountants relating to the Registration Statement, but the Company is not obligated to pay any underwriting discounts and commissions, brokers' commissions or charges, the legal fees and expenses of the Selling Stockholders, or transfer taxes, if any, relating to the sale or disposition of Shares by a Selling Shareholder. The Selling Stockholders may also resell Shares in open market transactions pursuant to the resale provisions of Rule 144contribution toward certain civil liabilities, including liabilities under the Securities Act or in transactions otherwise permitted under the Securities Act. LEGAL MATTERS Certain legal matters in connection with the Shares, including the validity

EXPERTS

The consolidated financial statements and schedule of the Shares, will be passed uponCompany for the Company by Rudnick & Wolfe, Chicago, Illinois. EXPERTS The financial statements of MFRI, Inc.years ended January 31, 2006 and subsidiaries incorporated2005 appearing in this Prospectus by reference from the Company'sCompany’s Annual Report on Form 10-K for the year ended January 31, 19972006 have been audited by Grant Thornton LLP, an independent registered public accounting firm, as set forth in their reports thereon included therein, and incorporated herein by reference. Such financial statements have been incorporated herein by reference, in reliance upon such reports given on the authority of such firm as experts in accounting and auditing.

The consolidated financial statements and related financial statement schedule for the year ended January 31, 2004, incorporated in this prospectus by reference from the Company’s Annual Report on Form 10-K for the year ended January 31, 2006, have been audited by Deloitte & Touche LLP, an independent auditors,registered public accounting firm, as stated in their report, which is incorporated herein by reference, and have been so incorporated in reliance upon the report of such firm given upon their authority as experts in accounting and auditing. INFORMATION INCORPORATED BY REFERENCE

LEGAL MATTERS

The following documents previously filedlegality of the Common Shares offered by the Company has been passed upon for us by the law firm of DLA Piper US LLP, Chicago, Illinois. DLA Piper US LLP attorneys who are participating in the representation of the Company in this offering own an aggregate of 3,100 Common Shares.


1,500,000 Shares

MFRI, INC.

Common Stock

PROSPECTUS

_______________, 2006




PART II

INFORMATION NOT REQUIRED IN PROSPECTUS

Item 14.Other Expenses Of Issuance And Distribution

The following table sets forth those expenses for distribution to be incurred in connection with the Commission pursuantissuance and distribution of the securities being registered.

Registration Fee

$3,535

Legal Fees and Expenses*

7,500

Accounting Fees and Expenses*

20,000

Printing and Duplicating Expenses*

1,000

Miscellaneous*

1,000

Total*

$33,035

__________

* Estimated

 II-1



Item 15. Indemnification Of Directors And Officers

Section 145 of the Delaware General Corporation Law authorizes indemnification of directors, officers, employees and agents of the Company; allows the advancement of costs of defending against litigation; and permits companies incorporated in Delaware to purchase insurance on behalf of directors, officers, employees and agents against liabilities whether or not in the circumstances such companies would have the power to indemnify against such liabilities under the provisions of the statute.

The Company’s Certificate of Incorporation and its By-Laws provide for indemnification of its officers and directors to the Exchange Act (SEC File No. 1-18370)full extent permitted by Section 145 of the Delaware General Corporation Law.

The Company’s Certificate of Incorporation eliminates, to the fullest extent permitted by Delaware law, liability of a director to the Company or its stockholders for monetary damages for breach of such director’s fiduciary duty of care except for liability where a director (a) breaches his or her duty of loyalty to the Company or its stockholders, (b) fails to act in good faith or engages in intentional misconduct or knowing violation of law, (c) authorizes payment of an illegal dividend or a stock repurchase or (d) obtains an improper personal benefit. While liability for monetary damages has been eliminated, equitable remedies such as injunctive relief or rescission remain available. In addition, a director is not relieved of his responsibilities under any other law, including the federal securities laws.

The Company has entered into indemnification agreements in the form described below with each person who is currently a member of the Board of Directors of the Company and will enter into such agreements with persons who in the future become directors of the Company. Such indemnification agreements provide for indemnification against any and all expenses incurred in connection with, as well as any and all judgments, fines, and amounts paid in settlement resulting from, any threatened, pending, or completed action, suit, or proceeding, whether civil, criminal, administrative, or investigative (collectively an “Action”), by reason of the fact that such director is or was a director, officer, employee or agent of the Company, or is or was serving at the request of the Company as a director, officer, employee or agent of another corporation, partnership, joint venture, trust, or other enterprise. The indemnification agreements provide that if any payment, advance or indemnification of the director requires that he or she acted in good faith, in a manner he or she reasonably believed to be for or not opposed to the best interests of the Company or without reasonable cause to believe his or her conduct was unlawful, then it shall be presumed that he or she so acted unless proven otherwise by clear and convincing evidence. The indemnification agreements also provide for the advancement of all expenses, including reasonable attorneys’ fees, arising from the investigation of any claim, preparation for the defense or defense or settlement of an Action. The indemnification agreements authorize the Company to participate in the defense of any action and to assume the defense thereof, with counsel who shall be reasonably satisfactory to the director, provided that the director shall be entitled to separate counsel of his or her choosing if he or she reasonably believes that (i) there exists conflicts interests between himself or herself and the Company or other parties (the defense of whom the Company shall have assumed) or (ii) there is any substantial likelihood that the Company will be financially or legally unable to satisfy its obligations under the Indemnification Agreement. The indemnification agreements provide that a director’s rights under such contract are hereby incorporated by reference into this Prospectus: not exclusive of any other indemnification rights he or she may have under any provision of law, the Company’s Certificate of Incorporation or By-laws, the vote of the Company’s stockholders or disinterested directors, other agreements or otherwise.

ITEM 16. Exhibits

4.1*

-

Certificate of Incorporation of MFRI, Inc.

4.2**

-

By-laws of MFRI, Inc.

5

-

Opinion of DLA Piper US LLP

23.1

-

Consent of Grant Thornton LLP

23.2

Consent of Deloitte & Touche LLP

23.3

-

Consent of DLA Piper US LLP (included in Exhibit 5)

24

-

Power of Attorney

____________________

*

Incorporated by reference to Exhibit 3.3 to Registration Statement No. 33-70298.

**

Incorporated by reference to Exhibit 3.4 to Registration Statement No. 33-70298.

ITEM 17. Undertakings

(a)

The undersigned Registrant hereby undertakes:

(1)

To file, during any period in which offers or sales are being made, a post-effective amendment to this registration statement:

II-2 



(i)

To include any prospectus required by section 10(a)(3) of the Securities Act of 1933;

(ii)

To reflect in the prospectus any facts or events arising after the effective date of the registration statement (or the most recent post-effective amendment thereof) which, individually or in the aggregate, represent a fundamental change in the information set forth in this registration statement. Notwithstanding the foregoing, any increase or decrease in volume of securities offered (if the total dollar value of securities offered would not exceed that which was registered) and any deviation from the low or high end of the estimated maximum offering range may be reflected in the form of prospectus filed with the Commission pursuant to Rule 424(b) if, in the aggregate, the changes in volume and price represent no more than a 20 percent change in the maximum aggregate offering price set forth in the “Calculation of Registration Fee” table in the effective registration statement;

(iii)

To include any material information with respect to the plan of distribution not previously disclosed in the registration statement or any material change to such information in this registration statement;

provided, however, that subparagraphs (i) and (ii) above do not apply if the registration statement of the Company's predecessoris on Form 8-AS-3, Form S-8 or Form F-3, and the information required to be included in a post-effective amendment by those paragraphs is contained in the periodic reports filed on Marchwith or furnished to the Commission by the Registrant pursuant to Section 13 1990 registering common stock of the Company's predecessor underor Section 12(g)15(d) of the Securities Exchange Act of 1934; (ii) the Company's Annual Report on Form 10-K1934 that are incorporated by reference in this registration statement.

(2)           That, for the fiscal year ended January 31, 1997;purpose of determining any liability under the Securities Act of 1933, each such post-effective amendment shall be deemed to be a new registration statement relating to the securities offered herein, and (iii) the Company's Current Report on Form 8-K dated December 30, 1996. All documents filedoffering of such securities at that time shall be deemed to be the initial bonafide offering thereof.

(3)           To remove from registration by the Company pursuant to Section 13(a), 13(c), 14 or 15(d)means of a post-effective amendment any of the Exchange Act after the date of this Prospectus and beforesecurities being registered which remain unsold at the termination of the offeringoffering.

(4)           That, for the purpose of sharesdetermining liability under the Securities Act of 1933 to any purchaser:

(A)          Each prospectus filed by a registrant pursuant to Rule 424(b)(3) shall be deemed to be part of the Common Stockregistration statement as of the date the filed prospectus was deemed part of and included in the registration statement; and

(B)          Each prospectus required to be filed pursuant to Rule 424(b)(2), (b)(5) or (b)(7) as part of a registration statement in reliance on Rule 430B relating to an offering made hereby are hereby incorporatedpursuant to Rule 415(a)(1)(i), (vii) or (x) for the purpose of providing the information required by reference,Section 10(a) of the Securities Acct of 1933 shall be deemed to be part of and included in the registration statement as of the earlier of the date such documents areform of prospectus is first used after effectiveness or the date of the first contract of sale of securities in the offering described in the prospectus. As provided in Rule 430B, for liability purposes of the issuer and any person that is at that date an underwriter, such date shall be deemed to be a part hereof from thenew effective date of filingthe registration statement relating to the securities in the registration statement to which the prospectus relates, and the offering of such documents. Anysecurities at that time shall be deemed to be the initial bona fide offering thereof. Provided, however, that no statement containedmade in a registration statement or prospectus that is part of the registration statement or made in a document incorporated or deemed to be incorporated by reference hereininto the registration statement or prospectus that is part of the registration statement will, as to a purchaser with a time of contract of sale prior to such effective date, supersede or modify any statement that was made in the registration statement or prospectus that was part of the registration statement or made in any such document immediately prior to such effective date.

(5)           That, for the purpose of determining liability of a registrant under the Securities Act of 1933 to any purchaser in the initial distribution of the securities, the registrant undertakes that in a primary offering of securities of the registrant pursuant to this registration statement, regardless of the underwriting method used to sell the securities to the purchaser, if the securities are offered or sold to such purchaser by means of any of the following communications, the registrant will be a seller to the purchaser and will be considered to offer or sell such securities to such purchaser:

(i)

Any preliminary prospectus or prospectus of the registrant relating to the offering required to be filed pursuant to Rule 424;

(ii)

Any free writing prospectus relating to the offering prepared by or on behalf of the registrant or used or referred to by the registrant;

II-3 



(iii)

The portion of any other free writing prospectus relating to the offering containing material information about the registrant or its securities provided by or on behalf of the registrant; and

(iv)

Any other communication that is an offer in the offering made by the registrant to the purchaser.

(b)           The undersigned Registrant hereby further undertakes that, for the purposes of determining any liability under the Securities Act of 1933, each filing of the Registrant’s annual report pursuant to Section 13(a) or Section 15(d) of the Securities Exchange Act of 1934 that is incorporated by reference in this registration statement shall be modified or superseded for purposes of this Prospectus to the extent that a statement contained herein or in any other subsequently filed document which is or is deemed to be incorporated by reference herein modifies or supersedes such statement. Any sucha new registration statement so modified or superseded shall not, except as so modified or superseded, constitute a part of this Prospectus. THE COMPANY WILL PROVIDE WITHOUT CHARGE TO EACH PERSON, INCLUDING ANY BENEFICIAL OWNER OF COMMON STOCK, TO WHOM A COPY OF THIS PROSPECTUS IS DELIVERED, UPON THE ORAL OR WRITTEN REQUEST OF SUCH PERSON, A COPY OF ANY AND ALL OF THE INFORMATION THAT HAS BEEN INCORPORATED BY REFERENCE IN THIS PROSPECTUS (NOT INCLUDING EXHIBITS TO THE INFORMATION THAT IS INCORPORATED BY REFERENCE UNLESS SUCH EXHIBITS ARE SPECIFICALLY INCORPORATED BY REFERENCE IN SUCH INFORMATION). SUCH REQUEST SHOULD BE DIRECTED TO MICHAEL D. BENNETT, SECRETARY, MFRI, INC., 7720 LEHIGH AVENUE, NILES, ILLINOIS 60714 (TELEPHONE (847) 966-1000). PART II INFORMATION NOT REQUIRED IN PROSPECTUS Item 16. EXHIBITS. EXHIBIT EXHIBIT NUMBER DESCRIPTION 2.1 Agreement for Merger by and between Midwesco, Inc. and MFRI, Inc. [Incorporated by reference to Appendix A to the Company's Proxy Statement dated November 12, 1996 relating to the Company's Special Meetingsecurities offered herein, and the offering of Stockholders held on December 16, 1996 (SEC File No. 0-18370)]. 2.2 Agreementsuch securities at that time shall be deemed to be the initial bona fide offering thereof.

(c)           Insofar as indemnification for liabilities arising under the Securities Act of 1933 may be permitted to directors, officers and Plancontrolling persons of Merger by and between Midwesco, Inc. and MFRI, Inc. [Incorporated by reference to Exhibit 2. 2the Registrant pursuant to the Company's Current Report on Form 8-K dated December 30, 1996 (SEC File No. 0-18370)]. 5 Opinion of Rudnick & Wolfe with respect toforegoing provisions or otherwise, the legalityregistrant has been advised that in the opinion of the Common Stock being registered. 23.1 ConsentSecurities and Exchange Commission such indemnification is against public policy as expressed in the Act and is, therefore, unenforceable. In the event that a claim for indemnification against such liabilities (other than the payment by the registrant of Deloitte & Touche LLP. 23.2 Consent of Rudnick & Wolfe (contained in Exhibit 5 hereof). 24.1 Power of Attorney of Directors and certain officersexpenses incurred or paid by a trustee, officer or controlling person of the Company.* 24.2 Powerregistrant in the successful defense of Attorneyany action, suit or proceeding) is asserted by such trustee, officer or controlling person in connection with the securities being registered, the Registrant will, unless in the opinion of certain Directorsits counsel the matter has been settled by controlling precedent, submit to a court of appropriate jurisdiction the Company. * Previously filed. question whether such indemnification by it is against public policy as expressed in the Act and will be governed by the final adjudication of such issue.

II-4 



SIGNATURES

Pursuant to the requirements of the Securities Act of 1933, the registrantRegistrant certifies that it has reasonable grounds to believe that it meets all of the requirements for filing on Form S-3 and has duly caused this amendment to registration statementRegistration Statement to be signed on its behalf by the undersigned, thereunto duly authorized, in the City of Niles, State of Illinois, on May 2, 1997. MFRI, INC. By: /S/ DAVID UNGER David Unger Chairman of the Board and Chief Executive Officer

MFRI, INC.

By:

/s/ David Unger

David Unger, Chairman of the Board and Chief Executive Officer

Pursuant to the requirements of the Securities Act of 1933, this amendment to registration statementRegistration Statement has been signed below by the following persons in the capacities set forth below and on the date indicated. dates indicated:

SIGNATURE TITLE DATE

Signature

Title

Date**

David Unger*

Director, Chief Executive Officer and Chairman of the Board of Directors (Principal Executive Officer) May 2, 1997

Bradley E. Mautner*

Director, President and Chief Operating Officer

Henry M. Mautner*

Director and Vice Chairman of the Board of Directors May 2, 1997 Gene K. Ogilvie* Director and Vice President May 2, 1997 Bradley E. Mautner* Director and Vice President May 2, 1997

Michael D. Bennett*

Vice President, Secretary and Treasurer (Principal Financial and Accounting Officer) May 2, 1997 Fati Elgendy* Director and Vice President May 2, 1997 Don Gruenberg* Director and Vice President May 2, 1997

Arnold F. Brookstone* Director May 2, 1997

Dennis Kessler*

Eugene Miller* Director May 2, 1997

Stephen B. Schwartz*

Director May 2, 1997 *By:

Director

Director

Director

*By

/S/ DAVID UNGER s/ David Unger


Individually and as Attorney- May 2, 1997 Attorney-in-fact

David Unger in-fact EXHIBIT INDEX EXHIBIT EXHIBIT NUMBER DESCRIPTION 2.1 Agreement for Merger by and between Midwesco, Inc. and

**December 15, 2006

II-5 



EXHIBIT INDEX

Exhibit

Number

Exhibit

Description

4.1*

Certificate of Incorporation of MFRI, Inc. [Incorporated by reference to Appendix A to the Company's Proxy Statement dated November 12, 1996 relating to the Company's Special Meeting

4.2**

By-laws of Stockholders held on December 16, 1996 (SEC File No. 0-18370)]. 2.2 Agreement and Plan of Merger by and between Midwesco, Inc. and MFRI, Inc. [Incorporated by reference to Exhibit 2. 2 to the Company's Current Report on Form 8-K dated December 30, 1996 (SEC file No. 0-18370)].

5

Opinion of Rudnick & Wolfe with respect to the legalityDLA Piper US LLP

23.1

Consent of the Common Stock being registered. 23.1 Grant Thornton LLP

23.2

Consent of Deloitte & Touche LLP. 23.2 LLP

23.3

Consent of Rudnick & Wolfe (containedDLA Piper US LLP (included in Exhibit 5 hereof). 24.1 5)

24

Power of Attorney of the Directors and certain officers of the Company.

____________________

* 24.2 Power of Attorney of certain Directors of the Company. *Previously filed. EXHIBIT 5 RUDNICK & WOLFE 203 NORTH LASALLE STREET CHICAGO, ILLINOIS 60601-1293 May 2, 1997 (312) 368-4000 The Board of Directors MFRI, Inc. 7720 Lehigh Avenue Niles, IL 60714 Gentlemen: We have examined the registration statement on Form S-3 (Registration No. 333-21951) filed with the Securities and Exchange Commission on or about February 17, 1997, for registration under the Securities Act of 1933, as amended, of 2,124,298 shares of common stock of MFRI, Inc., a Delaware corporation (the "Company"), par value $. 01 per share ("Common Stock"). We have examined pertinent corporate documents and records of the Company, including its Certificate of Incorporation and its By-Laws, and we are familiar with the corporate proceedings had and contemplated in connection with the issuance of such shares of Common Stock

Incorporated by the Company. We have also made such other examinations as we have deemed necessary or appropriate as a basis for the opinion hereinafter expressed. On the basis of the foregoing, we are of the opinion that such 2,124,298 shares of Common Stock of the Company have been duly authorized, and are legally issued, fully paid and non-assessable. We hereby consent to the filing of this opinion as an exhibit to the registration statement and to the reference to our firm in the registration statement under the caption "Legal Matters." Very truly yours, RUDNICK & WOLFE By: /S/ DORIAN R. WILLIAMS Dorian R. Williams, a Partner EXHIBIT 23. 1 CONSENT OF INDEPENDENT ACCOUNTANTS We consentExhibit 3.3 to the incorporationRegistration Statement No. 33-70298.

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Incorporated by reference in thisto Exhibit 3.4 to Registration Statement of MFRI, Inc. on Form S-3 of our report dated April 18, 1997, appearing in the Annual Report on Form 10-K of MFRI, Inc. for the year ended January 31, 1997 and to the reference to us under the "Experts" in the Prospectus, which is part of this Registration Statement. /S/ DELOITTE & TOUCHE LLP Deloitte & Touche LLP Chicago, Illinois May 2, 1997 EXHIBIT 24.2 POWER OF ATTORNEY KNOW ALL MEN BY THESE PRESENTS, that each of the undersigned, being a director or officer, or both, of MFRI, Inc., a Delaware corporation (the "Company"), does hereby constitute and appoint David Unger, Henry M. Mautner, Bradley E. Mautner, Fati Elgendy and Michael D. Bennett with full power of substitution and resubstitution to each of said attorneys, to execute, file or deliver any and all instruments and to do any and all acts and things which said attorneys and agents, or any of them, deem advisable to enable the Company to comply with the Securities Act of 1933, as amended, and any requirements or regulations of the Securities and Exchange Commission in respect thereto, in connection with the registration under said Securities Act of the sale of shares of common stock of the Company by certain stockholders of the Company, which shares were issued by the Company in connection with the merger of Midwesco, Inc., an Illinois corporation, and the Company, including specifically, but without limitation of the general authority hereby granted, the power and authority to sign his or her name as director or officer, or both, of the Company, as indicated below opposite his or her signature, to the registration statements and any amendment, post-effective amendment, supplement or papers supplemental thereto, to be filed with respect to said shares of common stock, and each of the undersigned does hereby fully ratify and confirm all that said attorneys and agents, or any one of them, or the substitute of any of them, shall do or cause to be done by virtue hereof. IN WITNESS WHEREOF, each of the undersigned has subscribed these presents, this 2nd day of May, 1997. SIGNATURE TITLE /S/ ARNOLD F. BROOKSTONE Arnold F. Brookstone, Director /s/ STEPHEN B. SCHWARTZ Stephen B. Schwartz, Director No. 33-70298.