Sec Form 4 Filing - Cook Benton Lowell @ CECO ENVIRONMENTAL CORP - 2012-03-20

FORM 4 Check this box if no longer subject to Section 16. Form 4 or Form 5 obligations may continue. See Instruction 1(b).

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 STATEMENT OF CHANGES IN BENEFICIAL OWNERSHIP Filed pursuant to Section 16(a) of the Securities Exchange Act of 1934, Section 17(a) of the Public Utility Holding Company Act of 1935 or Section 30(h) of the Investment Company Act of 1940

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1. Name and Address of Reporting Person Cook Benton Lowell 2. Issuer Name and Ticker or Trading Symbol CECO ENVIRONMENTAL CORP [ CECE] 5. Relationship of Reporting Person(s) to Issuer (Check all applicable) _____ Director _____ 10% Owner X __ Officer (give title below) _____ Other (specify below) Interim CFO (Last) (First) (Middle) 4625 RED BANK ROAD, SUITE 200 3. Date of Earliest Transaction (MM/DD/YY) 03/20/2012 (Street) CINCINNATI, OH45227 4. If Amendment, Date Original Filed (MM/DD/YY) 6. Individual or Joint/Group Filing (Check Applicable Line) __ X __ Form filed by One Reporting Person _____ Form filed by More than One Reporting Person (City) (State) (Zip)

Table I - Non-Derivative Securities Acquired, Disposed of, or Beneficially Owned 1.Title of Security (Instr. 3) 2. Transaction Date (MM/DD/YY) 2A. Deemed Execution Date, if any (MM/DD/YY) 3. Transaction Code (Instr. 8) 4. Securities Acquired (A) or Disposed of (D) (Instr. 3, 4 and 5) 5. Amount of Securities Beneficially Owned Following Reported Transaction(s) (Instr. 3 and 4) 6. Ownership Form: Direct (D) or Indirect (I) (Instr. 4) 7. Nature of Indirect Beneficial Ownership (Instr. 4) Code V Amount (A) or (D) Price Common Stock 03/20/2012 M 1,000 A $ 1.98 1,000 D Common Stock 03/20/2012 M 2,000 A $ 5.26 3,000 D Common Stock 03/20/2012 S 200 D $ 8.41 2,800 D Common Stock 03/20/2012 S 100 D $ 8.37 2,700 D Common Stock 03/20/2012 S 200 D $ 8.36 2,500 D Common Stock 03/20/2012 S 1,500 D $ 8.35 1,000 D Common Stock 03/20/2012 S 800 D $ 8.35 200 D Common Stock 03/20/2012 S 75 D $ 8.33 125 D Common Stock 03/20/2012 S 125 D $ 8.32 0 D

Table II - Derivative Securities Acquired, Disposed of, or Beneficially Owned ( e.g. , puts, calls, warrants, options, convertible securities) 1. Title of Derivative Security (Instr. 3) 2. Conversion or Exercise Price of Derivative Security 3. Transaction Date (MM/DD/YY) 3A. Deemed Execution Date, if any (MM/DD/YY) 4. Transaction Code (Instr. 8) 5. Number of Derivative Securities Acquired (A) or Disposed of (D) (Instr. 3, 4, and 5) 6. Date Exercisable and Expiration Date (MM/DD/YY) 7. Title and Amount of Underlying Securities (Instr. 3 and 4) 8. Price of Derivative Security (Instr. 5) 9. Number of Derivative Securities Beneficially Owned Following Reported Transaction(s) (Instr. 4) 10. Ownership Form of Derivative Security: Direct (D) or Indirect (I) (Instr. 4) 11. Nature of Indirect Beneficial Ownership (Instr. 4) Code V (A) (D) Date Exercisable Expiration Date Title Amount or Number of Shares Employee Stock Option (right to buy) $ 5.26 03/20/2012 M 2,000 ( 1 ) 04/29/2020 Common Stock 2,000 $ 0 4,000 D Employee Stock Option (right to buy) $ 1.98 03/20/2012 M 1,000 ( 2 ) 12/01/2018 Common Stock 1,000 $ 0 2,000 D

Reporting Owners Reporting Owner Name / Address Relationships Director 10% Owner Officer Other Cook Benton Lowell 4625 RED BANK ROAD SUITE 200 CINCINNATI, OH45227 Interim CFO Signatures /s/ Benton Cook 03/22/2012 Signature of Reporting Person Date

Explanation of Responses:

( 1 )Shares are from an option for 6,000 shares, 2,000 of which vested on April 29, 2011, and 2,000 of which vest on each of April 29, 2012 and April 29, 2013. ( 2 )Shares are from an option for 3,000 shares, 1,000 of which vested on December 1, 2011, and 1,000 of which vest on each of December 1, 2012 and December 1, 2013.

Reminder: Report on a separate line for each class of securities beneficially owned directly or indirectly.

* If the form is filed by more than one reporting person, see Instruction 4(b)(v).

** Intentional misstatements or omissions of facts constitute Federal Criminal Violations. See 18 U.S.C. 1001 and 15 U.S.C. 78ff(a).

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