<SEC-DOCUMENT>0001193125-13-349447.txt : 20130828
<SEC-HEADER>0001193125-13-349447.hdr.sgml : 20130828
<ACCEPTANCE-DATETIME>20130828102923
ACCESSION NUMBER:		0001193125-13-349447
CONFORMED SUBMISSION TYPE:	POS EX
PUBLIC DOCUMENT COUNT:		3
FILED AS OF DATE:		20130828
DATE AS OF CHANGE:		20130828
EFFECTIVENESS DATE:		20130828

FILER:

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			CECO ENVIRONMENTAL CORP
		CENTRAL INDEX KEY:			0000003197
		STANDARD INDUSTRIAL CLASSIFICATION:	INDUSTRIAL & COMMERCIAL FANS & BLOWERS & AIR PURIFYING EQUIP [3564]
		IRS NUMBER:				132566064
		STATE OF INCORPORATION:			DE
		FISCAL YEAR END:			1231

	FILING VALUES:
		FORM TYPE:		POS EX
		SEC ACT:		1933 Act
		SEC FILE NUMBER:	333-188797
		FILM NUMBER:		131064652

	BUSINESS ADDRESS:	
		STREET 1:		4625 RED BANK ROAD, SUITE 200
		CITY:			CINCINNATI
		STATE:			OH
		ZIP:			45227
		BUSINESS PHONE:		4165936543

	MAIL ADDRESS:	
		STREET 1:		2300 YONGE STREET, P.O. BOX 2408
		STREET 2:		SUITE 1710
		CITY:			TORONTO
		STATE:			A6
		ZIP:			M4P 1E4

	FORMER COMPANY:	
		FORMER CONFORMED NAME:	API ENTERPRISES INC
		DATE OF NAME CHANGE:	19920703

	FORMER COMPANY:	
		FORMER CONFORMED NAME:	ALARM PRODUCTS INTERNATIONAL INC
		DATE OF NAME CHANGE:	19851210
</SEC-HEADER>
<DOCUMENT>
<TYPE>POS EX
<SEQUENCE>1
<FILENAME>d589759dposex.htm
<DESCRIPTION>POS EX
<TEXT>
<HTML><HEAD>
<TITLE>POS EX</TITLE>
</HEAD>
 <BODY BGCOLOR="WHITE">

 <P STYLE="margin-top:0px;margin-bottom:0px" ALIGN="center"><FONT STYLE="font-family:Times New Roman" SIZE="2"><B>As filed with the Securities and Exchange Commission on August&nbsp;28, 2013.
</B></FONT></P> <P STYLE="margin-top:0px;margin-bottom:0px" ALIGN="right"><FONT STYLE="font-family:Times New Roman" SIZE="2"><B>Registration No.&nbsp;333-188797 </B></FONT></P> <P STYLE="font-size:4px;margin-top:0px;margin-bottom:0px">&nbsp;</P>
<P STYLE="line-height:0px;margin-top:0px;margin-bottom:0px;border-bottom:0.5pt solid #000000">&nbsp;</P> <P STYLE="line-height:3px;margin-top:0px;margin-bottom:2px;border-bottom:0.5pt solid #000000">&nbsp;</P>
<P STYLE="margin-top:4px;margin-bottom:0px" ALIGN="center"><FONT STYLE="font-family:Times New Roman" SIZE="5"><B>UNITED STATES </B></FONT></P> <P STYLE="margin-top:0px;margin-bottom:0px" ALIGN="center"><FONT
STYLE="font-family:Times New Roman" SIZE="5"><B>SECURITIES AND EXCHANGE COMMISSION </B></FONT></P> <P STYLE="margin-top:0px;margin-bottom:0px" ALIGN="center"><FONT STYLE="font-family:Times New Roman" SIZE="3"><B>Washington, DC 20549 </B></FONT></P>
<P STYLE="font-size:12px;margin-top:0px;margin-bottom:0px">&nbsp;</P><center> <P STYLE="line-height:6px;margin-top:0px;margin-bottom:2px;border-bottom:1pt solid #000000;width:21%">&nbsp;</P></center>
<P STYLE="margin-top:12px;margin-bottom:0px" ALIGN="center"><FONT STYLE="font-family:Times New Roman" SIZE="5"><B>Post-Effective Amendment No.&nbsp;1 </B></FONT></P> <P STYLE="margin-top:0px;margin-bottom:0px" ALIGN="center"><FONT
STYLE="font-family:Times New Roman" SIZE="5"><B>to </B></FONT></P> <P STYLE="margin-top:0px;margin-bottom:0px" ALIGN="center"><FONT STYLE="font-family:Times New Roman" SIZE="5"><B>Form S-4 </B></FONT></P>
<P STYLE="margin-top:0px;margin-bottom:0px" ALIGN="center"><FONT STYLE="font-family:Times New Roman" SIZE="5"><B>REGISTRATION STATEMENT </B></FONT></P> <P STYLE="margin-top:0px;margin-bottom:0px" ALIGN="center"><FONT
STYLE="font-family:Times New Roman" SIZE="3"><B><I>UNDER </I></B></FONT></P> <P STYLE="margin-top:0px;margin-bottom:0px" ALIGN="center"><FONT STYLE="font-family:Times New Roman" SIZE="3"><B><I>THE SECURITIES ACT OF 1933 </I></B></FONT></P>
<P STYLE="font-size:12px;margin-top:0px;margin-bottom:0px">&nbsp;</P><center> <P STYLE="line-height:6px;margin-top:0px;margin-bottom:2px;border-bottom:1pt solid #000000;width:21%">&nbsp;</P></center>
<P STYLE="margin-top:12px;margin-bottom:0px" ALIGN="center"><FONT STYLE="font-family:Times New Roman" SIZE="6"><B>CECO Environmental Corp. </B></FONT></P> <P STYLE="margin-top:0px;margin-bottom:0px" ALIGN="center"><FONT
STYLE="font-family:Times New Roman" SIZE="2"><B>(Exact name of registrant as specified in its charter) </B></FONT></P> <P STYLE="font-size:12px;margin-top:0px;margin-bottom:0px">&nbsp;</P><center>
<P STYLE="line-height:6px;margin-top:0px;margin-bottom:2px;border-bottom:1pt solid #000000;width:21%">&nbsp;</P></center> <P STYLE="font-size:12px;margin-top:0px;margin-bottom:0px">&nbsp;</P>
<TABLE CELLSPACING="0" CELLPADDING="0" WIDTH="100%" BORDER="0" STYLE="BORDER-COLLAPSE:COLLAPSE" ALIGN="center">


<TR>
<TD WIDTH="34%"></TD>
<TD VALIGN="bottom"></TD>
<TD WIDTH="32%"></TD>
<TD VALIGN="bottom" WIDTH="1%"></TD>
<TD WIDTH="32%"></TD></TR>


<TR>
<TD VALIGN="top" ALIGN="center"><FONT STYLE="font-family:Times New Roman" SIZE="2"><B>Delaware</B></FONT></TD>
<TD VALIGN="bottom"><FONT SIZE="1">&nbsp;</FONT></TD>
<TD VALIGN="top" ALIGN="center"><FONT STYLE="font-family:Times New Roman" SIZE="2"><B>3564</B></FONT></TD>
<TD VALIGN="bottom"><FONT SIZE="1">&nbsp;</FONT></TD>
<TD VALIGN="top" ALIGN="center"><FONT STYLE="font-family:Times New Roman" SIZE="2"><B>13-2566064</B></FONT></TD></TR>
<TR>
<TD VALIGN="top" ALIGN="center"> <P STYLE="margin-top:0px;margin-bottom:0px" ALIGN="center"><FONT STYLE="font-family:Times New Roman" SIZE="1"><B>(State or other jurisdiction of</B></FONT></P>
<P STYLE="margin-top:0px;margin-bottom:1px" ALIGN="center"><FONT STYLE="font-family:Times New Roman" SIZE="1"><B>incorporation or organization)</B></FONT></P></TD>
<TD VALIGN="bottom"><FONT SIZE="1">&nbsp;</FONT></TD>
<TD VALIGN="top" ALIGN="center"> <P STYLE="margin-top:0px;margin-bottom:0px" ALIGN="center"><FONT STYLE="font-family:Times New Roman" SIZE="1"><B>(Primary Standard Industrial</B></FONT></P> <P STYLE="margin-top:0px;margin-bottom:1px" ALIGN="center"><FONT
STYLE="font-family:Times New Roman" SIZE="1"><B>Classification Code Number)</B></FONT></P></TD>
<TD VALIGN="bottom"><FONT SIZE="1">&nbsp;</FONT></TD>
<TD VALIGN="top" ALIGN="center"> <P STYLE="margin-top:0px;margin-bottom:0px" ALIGN="center"><FONT STYLE="font-family:Times New Roman" SIZE="1"><B>(I.R.S. Employer</B></FONT></P> <P STYLE="margin-top:0px;margin-bottom:1px" ALIGN="center"><FONT
STYLE="font-family:Times New Roman" SIZE="1"><B>Identification Number)</B></FONT></P></TD></TR>
</TABLE> <P STYLE="margin-top:12px;margin-bottom:0px" ALIGN="center"><FONT STYLE="font-family:Times New Roman" SIZE="2"><B>4625 Red Bank Road, Suite 200 </B></FONT></P>
<P STYLE="margin-top:0px;margin-bottom:0px" ALIGN="center"><FONT STYLE="font-family:Times New Roman" SIZE="2"><B>Cincinnati, Ohio 45227 </B></FONT></P> <P STYLE="margin-top:0px;margin-bottom:0px" ALIGN="center"><FONT
STYLE="font-family:Times New Roman" SIZE="2"><B>(513) 458-2600 </B></FONT></P> <P STYLE="margin-top:0px;margin-bottom:0px" ALIGN="center"><FONT STYLE="font-family:Times New Roman" SIZE="1"><B>(Address, including zip code, and telephone number,
including area code, of registrant&#146;s principal executive offices) </B></FONT></P> <P STYLE="margin-top:12px;margin-bottom:0px" ALIGN="center"><FONT STYLE="font-family:Times New Roman" SIZE="2"><B>Jeffrey Lang </B></FONT></P>
<P STYLE="margin-top:0px;margin-bottom:0px" ALIGN="center"><FONT STYLE="font-family:Times New Roman" SIZE="2"><B>Chief Executive Officer </B></FONT></P> <P STYLE="margin-top:0px;margin-bottom:0px" ALIGN="center"><FONT
STYLE="font-family:Times New Roman" SIZE="2"><B>4625 Red Bank Road, Suite 200 </B></FONT></P> <P STYLE="margin-top:0px;margin-bottom:0px" ALIGN="center"><FONT STYLE="font-family:Times New Roman" SIZE="2"><B>Cincinnati, Ohio 45227 </B></FONT></P>
<P STYLE="margin-top:0px;margin-bottom:0px" ALIGN="center"><FONT STYLE="font-family:Times New Roman" SIZE="2"><B>Telephone: (513)&nbsp;458-2600 </B></FONT></P> <P STYLE="margin-top:0px;margin-bottom:0px" ALIGN="center"><FONT
STYLE="font-family:Times New Roman" SIZE="1"><B>(Name, address, including zip code, and telephone number, including area code, of agent for service) </B></FONT></P> <P STYLE="font-size:12px;margin-top:0px;margin-bottom:0px">&nbsp;</P><center>
<P STYLE="line-height:6px;margin-top:0px;margin-bottom:2px;border-bottom:1pt solid #000000;width:21%">&nbsp;</P></center> <P STYLE="margin-top:12px;margin-bottom:0px" ALIGN="center"><FONT STYLE="font-family:Times New Roman" SIZE="2"><B><I>Copies
to:</I></B></FONT></P> <P STYLE="font-size:12px;margin-top:0px;margin-bottom:0px">&nbsp;</P>
<TABLE CELLSPACING="0" CELLPADDING="0" WIDTH="100%" BORDER="0" STYLE="BORDER-COLLAPSE:COLLAPSE" ALIGN="center">


<TR>
<TD WIDTH="50%"></TD>
<TD VALIGN="bottom" WIDTH="1%"></TD>
<TD WIDTH="48%"></TD></TR>


<TR>
<TD VALIGN="top" ALIGN="center"> <P STYLE="margin-top:0px;margin-bottom:0px" ALIGN="center"><FONT STYLE="font-family:Times New Roman" SIZE="2"><B>Leslie J. Weiss</B></FONT></P> <P STYLE="margin-top:0px;margin-bottom:0px" ALIGN="center"><FONT
STYLE="font-family:Times New Roman" SIZE="2"><B>Barnes &amp; Thornburg LLP</B></FONT></P> <P STYLE="margin-top:0px;margin-bottom:0px" ALIGN="center"><FONT STYLE="font-family:Times New Roman" SIZE="2"><B>One North Wacker Drive</B></FONT></P>
<P STYLE="margin-top:0px;margin-bottom:0px" ALIGN="center"><FONT STYLE="font-family:Times New Roman" SIZE="2"><B>Suite 4400</B></FONT></P>
<P STYLE="margin-top:0px;margin-bottom:0px" ALIGN="center"><FONT STYLE="font-family:Times New Roman" SIZE="2"><B>Chicago, Illinois 60606</B></FONT></P> <P STYLE="margin-top:0px;margin-bottom:1px" ALIGN="center"><FONT
STYLE="font-family:Times New Roman" SIZE="2"><B>Telephone: (312) 214-4864</B></FONT></P></TD>
<TD VALIGN="bottom"><FONT SIZE="1">&nbsp;</FONT></TD>
<TD VALIGN="top" ALIGN="center"> <P STYLE="margin-top:0px;margin-bottom:0px" ALIGN="center"><FONT STYLE="font-family:Times New Roman" SIZE="2"><B>Jeffrey H. Nicholas</B></FONT></P> <P STYLE="margin-top:0px;margin-bottom:0px" ALIGN="center"><FONT
STYLE="font-family:Times New Roman" SIZE="2"><B>Vincent A. Vietti</B></FONT></P> <P STYLE="margin-top:0px;margin-bottom:0px" ALIGN="center"><FONT STYLE="font-family:Times New Roman" SIZE="2"><B>Fox Rothschild LLP</B></FONT></P>
<P STYLE="margin-top:0px;margin-bottom:0px" ALIGN="center"><FONT STYLE="font-family:Times New Roman" SIZE="2"><B>2000 Market Street, 20<FONT STYLE="font-family:Times New Roman" SIZE="1"><SUP
STYLE="vertical-align:baseline; position:relative; bottom:.8ex">th</SUP></FONT><FONT STYLE="font-family:Times New Roman" SIZE="2"> Floor</FONT></B></FONT></P> <P STYLE="margin-top:0px;margin-bottom:0px" ALIGN="center"><FONT
STYLE="font-family:Times New Roman" SIZE="2"><B>Philadelphia, Pennsylvania 19103</B></FONT></P> <P STYLE="margin-top:0px;margin-bottom:1px" ALIGN="center"><FONT STYLE="font-family:Times New Roman" SIZE="2"><B>Telephone: (215)
918-3639</B></FONT></P></TD></TR>
</TABLE> <P STYLE="font-size:12px;margin-top:0px;margin-bottom:0px">&nbsp;</P><center> <P STYLE="line-height:6px;margin-top:0px;margin-bottom:2px;border-bottom:1pt solid #000000;width:21%">&nbsp;</P></center>
<P STYLE="margin-top:12px;margin-bottom:0px"><FONT STYLE="font-family:Times New Roman" SIZE="2"><B>Approximate date of commencement of proposed sale of the securities to the public: </B>As soon as practicable after the registration statement becomes
effective and all other conditions to the proposed mergers described herein have been satisfied or waived. </FONT></P> <P STYLE="margin-top:12px;margin-bottom:0px"><FONT STYLE="font-family:Times New Roman" SIZE="2">If the securities being registered
on this Form are being offered in connection with the formation of a holding company and there is compliance with General Instruction G, check the following box.&nbsp;&nbsp;<FONT STYLE="FONT-FAMILY:WINGDINGS">&#168;</FONT> </FONT></P>
<P STYLE="margin-top:12px;margin-bottom:0px"><FONT STYLE="font-family:Times New Roman" SIZE="2">If this Form is filed to register additional securities for an offering pursuant to Rule 462(b) 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.&nbsp;&nbsp;<FONT STYLE="FONT-FAMILY:WINGDINGS">&#168;</FONT> </FONT></P> <P STYLE="margin-top:12px;margin-bottom:0px"><FONT
STYLE="font-family:Times New Roman" SIZE="2">If this form is a post-effective amendment filed pursuant to Rule 462(d) 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.&nbsp;&nbsp;<FONT STYLE="FONT-FAMILY:WINGDINGS">&#120;</FONT> </FONT></P> <P STYLE="margin-top:12px;margin-bottom:0px"><FONT STYLE="font-family:Times New Roman" SIZE="2">Indicate by check mark
whether the registrant is a large accelerated filer, an accelerated filer, a non-accelerated filer, or a smaller reporting company. See the definitions of &#147;large accelerated filer,&#148; &#147;accelerated filer&#148; and &#147;smaller reporting
company&#148; in Rule 12b-2 of the Exchange Act. </FONT></P> <P STYLE="margin-top:12px;margin-bottom:0px"><FONT STYLE="font-family:Times New Roman" SIZE="2">(Check one): </FONT></P>
<P STYLE="font-size:12px;margin-top:0px;margin-bottom:0px">&nbsp;</P>
<TABLE CELLSPACING="0" CELLPADDING="0" WIDTH="100%" BORDER="0" STYLE="BORDER-COLLAPSE:COLLAPSE" ALIGN="center">


<TR>
<TD WIDTH="16%"></TD>
<TD VALIGN="bottom" WIDTH="1%"></TD>
<TD WIDTH="60%"></TD>
<TD VALIGN="bottom" WIDTH="1%"></TD>
<TD WIDTH="20%"></TD>
<TD VALIGN="bottom" WIDTH="1%"></TD>
<TD WIDTH="1%"></TD></TR>


<TR>
<TD VALIGN="bottom"><FONT STYLE="font-family:Times New Roman" SIZE="2">Large&nbsp;accelerated&nbsp;filer</FONT></TD>
<TD VALIGN="bottom"><FONT SIZE="1">&nbsp;</FONT></TD>
<TD VALIGN="bottom"><FONT STYLE="font-family:Times New Roman" SIZE="2"><FONT STYLE="FONT-FAMILY:WINGDINGS">&#168;</FONT></FONT></TD>
<TD VALIGN="bottom"><FONT SIZE="1">&nbsp;&nbsp;</FONT></TD>
<TD VALIGN="bottom"><FONT STYLE="font-family:Times New Roman" SIZE="2">Accelerated&nbsp;filer</FONT></TD>
<TD VALIGN="bottom"><FONT SIZE="1">&nbsp;</FONT></TD>
<TD VALIGN="bottom"><FONT STYLE="font-family:Times New Roman" SIZE="2"><FONT STYLE="FONT-FAMILY:WINGDINGS">&#168;</FONT></FONT></TD></TR>
<TR>
<TD HEIGHT="8"></TD>
<TD HEIGHT="8" COLSPAN="2"></TD>
<TD HEIGHT="8" COLSPAN="2"></TD>
<TD HEIGHT="8" COLSPAN="2"></TD></TR>
<TR>
<TD VALIGN="bottom"><FONT STYLE="font-family:Times New Roman" SIZE="2">Non-accelerated filer</FONT></TD>
<TD VALIGN="bottom"><FONT SIZE="1">&nbsp;</FONT></TD>
<TD VALIGN="bottom"><FONT STYLE="font-family:Times New Roman" SIZE="2"><FONT STYLE="FONT-FAMILY:WINGDINGS">&#168;</FONT>&nbsp;&nbsp;(Do not check if a smaller reporting company)</FONT></TD>
<TD VALIGN="bottom"><FONT SIZE="1">&nbsp;&nbsp;</FONT></TD>
<TD VALIGN="bottom"><FONT STYLE="font-family:Times New Roman" SIZE="2">Smaller&nbsp;reporting&nbsp;company</FONT></TD>
<TD VALIGN="bottom"><FONT SIZE="1">&nbsp;</FONT></TD>
<TD VALIGN="bottom"><FONT STYLE="font-family:Times New Roman" SIZE="2"><FONT STYLE="FONT-FAMILY:WINGDINGS">&#120;</FONT></FONT></TD></TR>
</TABLE> <P STYLE="margin-top:12px;margin-bottom:0px"><FONT STYLE="font-family:Times New Roman" SIZE="2">If applicable, place an X in the box to designate the appropriate rule provision relied upon in conducting this
transaction: </FONT></P> <P STYLE="margin-top:12px;margin-bottom:0px"><FONT STYLE="font-family:Times New Roman" SIZE="2">Exchange Act Rule 13e-4(i) (Cross-Border Issuer Tender Offer)&nbsp;&nbsp;<FONT STYLE="FONT-FAMILY:WINGDINGS">&#168;</FONT>
</FONT></P> <P STYLE="margin-top:12px;margin-bottom:0px"><FONT STYLE="font-family:Times New Roman" SIZE="2">Exchange Act Rule 14d-1(d) (Cross-Border Third-Party Tender Offer)&nbsp;&nbsp;<FONT STYLE="FONT-FAMILY:WINGDINGS">&#168;</FONT> </FONT></P>
<P STYLE="font-size:10px;margin-top:0px;margin-bottom:0px">&nbsp;</P> <P STYLE="line-height:0px;margin-top:0px;margin-bottom:0px;border-bottom:0.5pt solid #000000">&nbsp;</P>
<P STYLE="line-height:3px;margin-top:0px;margin-bottom:2px;border-bottom:0.5pt solid #000000">&nbsp;</P>

<p Style='page-break-before:always'>
<HR  SIZE="3" style="COLOR:#999999" WIDTH="100%" ALIGN="CENTER">

 <P STYLE="margin-top:0px;margin-bottom:0px" ALIGN="center"><FONT STYLE="font-family:Times New Roman" SIZE="2"><B>EXPLANATORY NOTE </B></FONT></P>
<P STYLE="margin-top:12px;margin-bottom:0px; text-indent:4%"><FONT STYLE="font-family:Times New Roman" SIZE="2">This post&#150;effective Amendment No.&nbsp;1 to CECO Environmental Corp.&#146;s Registration Statement on Form S&#150;4 (Registration
No.&nbsp;333-188797) originally filed with the Securities and Exchange Commission on May&nbsp;23, 2013 (as amended by Amendment No.&nbsp;1, filed July&nbsp;3, 2013, and Amendment No.&nbsp;2, filed July&nbsp;22, 2013), is being filed for the sole
purpose of amending the exhibit index to include Exhibits No.&nbsp;2.2, 8.3, 8.4, 23.7 and 23.8 filed herewith. </FONT></P>

<p Style='page-break-before:always'>
<HR  SIZE="3" style="COLOR:#999999" WIDTH="100%" ALIGN="CENTER">

 <P STYLE="margin-top:0px;margin-bottom:0px"><FONT STYLE="font-family:Times New Roman" SIZE="2"><B><I></I></B><B>Item&nbsp;21. </B><B><I>Exhibits and Financial Statement Schedules. </I></B></FONT></P>
<P STYLE="margin-top:6px;margin-bottom:0px"><FONT STYLE="font-family:Times New Roman" SIZE="2">(a) Exhibits. The following Exhibits are filed as part of, or are incorporated by reference in, this Registration Statement: </FONT></P>
<P STYLE="font-size:12px;margin-top:0px;margin-bottom:0px">&nbsp;</P>
<TABLE CELLSPACING="0" CELLPADDING="0" WIDTH="100%" BORDER="0" STYLE="BORDER-COLLAPSE:COLLAPSE" ALIGN="center">


<TR>
<TD></TD>
<TD VALIGN="bottom" WIDTH="5%"></TD>
<TD WIDTH="92%"></TD></TR>
<TR>
<TD VALIGN="bottom" NOWRAP ALIGN="center"> <P STYLE="border-bottom:1px solid #000000;width:28pt" ALIGN="center"><FONT STYLE="font-family:Times New Roman" SIZE="1"><B>Exhibits</B></FONT></P></TD>
<TD VALIGN="bottom"><FONT SIZE="1">&nbsp;&nbsp;</FONT></TD>
<TD VALIGN="bottom">&nbsp;<FONT SIZE="1">&nbsp;</FONT></TD></TR>


<TR>
<TD HEIGHT="8"></TD>
<TD HEIGHT="8" COLSPAN="2"></TD></TR>
<TR>
<TD VALIGN="top" NOWRAP><FONT STYLE="font-family:Times New Roman" SIZE="2">&nbsp;&nbsp;2.1</FONT></TD>
<TD VALIGN="bottom"><FONT SIZE="1">&nbsp;&nbsp;</FONT></TD>
<TD VALIGN="top"><FONT STYLE="font-family:Times New Roman" SIZE="2">Agreement and Plan of Merger by and among Met-Pro Corporation, CECO Environmental Corp., Mustang Acquisition Inc. and Mustang Acquisition II Inc., dated as of April 21, 2013
(included as Annex A to the joint proxy statement/prospectus that is a part of this registration statement)*</FONT></TD></TR>
<TR>
<TD HEIGHT="8"></TD>
<TD HEIGHT="8" COLSPAN="2"></TD></TR>
<TR>
<TD VALIGN="top" NOWRAP><FONT STYLE="font-family:Times New Roman" SIZE="2">&nbsp;&nbsp;2.2</FONT></TD>
<TD VALIGN="bottom"><FONT SIZE="1">&nbsp;&nbsp;</FONT></TD>
<TD VALIGN="top"><FONT STYLE="font-family:Times New Roman" SIZE="2">Amendment No. 1 to Agreement and Plan of Merger by and among Met-Pro Corporation, CECO Environmental Corp., Mustang Acquisition Inc. and Mustang Acquisition II LLC (formerly known
as Mustang Acquisition II Inc.), dated as of August 5, 2013 (incorporated by reference to Exhibit 2.1 to the Form 8-K filed by CECO Environmental Corp. on August 8, 2013)</FONT></TD></TR>
<TR>
<TD HEIGHT="8"></TD>
<TD HEIGHT="8" COLSPAN="2"></TD></TR>
<TR>
<TD VALIGN="top" NOWRAP><FONT STYLE="font-family:Times New Roman" SIZE="2">&nbsp;&nbsp;5.1</FONT></TD>
<TD VALIGN="bottom"><FONT SIZE="1">&nbsp;&nbsp;</FONT></TD>
<TD VALIGN="top"><FONT STYLE="font-family:Times New Roman" SIZE="2">Opinion of Barnes &amp; Thornburg LLP, regarding the legality of the securities being issued**</FONT></TD></TR>
<TR>
<TD HEIGHT="8"></TD>
<TD HEIGHT="8" COLSPAN="2"></TD></TR>
<TR>
<TD VALIGN="top" NOWRAP><FONT STYLE="font-family:Times New Roman" SIZE="2">&nbsp;&nbsp;8.1</FONT></TD>
<TD VALIGN="bottom"><FONT SIZE="1">&nbsp;&nbsp;</FONT></TD>
<TD VALIGN="top"><FONT STYLE="font-family:Times New Roman" SIZE="2">Opinion of Barnes &amp; Thornburg LLP, regarding certain tax matters**</FONT></TD></TR>
<TR>
<TD HEIGHT="8"></TD>
<TD HEIGHT="8" COLSPAN="2"></TD></TR>
<TR>
<TD VALIGN="top" NOWRAP><FONT STYLE="font-family:Times New Roman" SIZE="2">&nbsp;&nbsp;8.2</FONT></TD>
<TD VALIGN="bottom"><FONT SIZE="1">&nbsp;&nbsp;</FONT></TD>
<TD VALIGN="top"><FONT STYLE="font-family:Times New Roman" SIZE="2">Opinion of Fox Rothschild LLP, regarding certain tax matters**</FONT></TD></TR>
<TR>
<TD HEIGHT="8"></TD>
<TD HEIGHT="8" COLSPAN="2"></TD></TR>
<TR>
<TD VALIGN="top" NOWRAP><FONT STYLE="font-family:Times New Roman" SIZE="2">&nbsp;&nbsp;8.3</FONT></TD>
<TD VALIGN="bottom"><FONT SIZE="1">&nbsp;&nbsp;</FONT></TD>
<TD VALIGN="top"><FONT STYLE="font-family:Times New Roman" SIZE="2">Opinion of Barnes &amp; Thornburg LLP, regarding U.S. tax matters (delivered to CECO Environmental Corp. at the closing of the mergers)</FONT></TD></TR>
<TR>
<TD HEIGHT="8"></TD>
<TD HEIGHT="8" COLSPAN="2"></TD></TR>
<TR>
<TD VALIGN="top" NOWRAP><FONT STYLE="font-family:Times New Roman" SIZE="2">&nbsp;&nbsp;8.4</FONT></TD>
<TD VALIGN="bottom"><FONT SIZE="1">&nbsp;&nbsp;</FONT></TD>
<TD VALIGN="top"><FONT STYLE="font-family:Times New Roman" SIZE="2">Opinion of Fox Rothschild LLP, regarding U.S. tax matters (delivered to Met-Pro Corporation at the closing of the mergers)</FONT></TD></TR>
<TR>
<TD HEIGHT="8"></TD>
<TD HEIGHT="8" COLSPAN="2"></TD></TR>
<TR>
<TD VALIGN="top" NOWRAP><FONT STYLE="font-family:Times New Roman" SIZE="2">10.1</FONT></TD>
<TD VALIGN="bottom"><FONT SIZE="1">&nbsp;&nbsp;</FONT></TD>
<TD VALIGN="top"><FONT STYLE="font-family:Times New Roman" SIZE="2">Voting Agreement of Icarus Investment Corp., Phillip DeZwirek and Jason DeZwirek, dated April 21, 2013 (included as Annex B to the joint proxy statement/prospectus that is a part of
this registration statement)</FONT></TD></TR>
<TR>
<TD HEIGHT="8"></TD>
<TD HEIGHT="8" COLSPAN="2"></TD></TR>
<TR>
<TD VALIGN="top" NOWRAP><FONT STYLE="font-family:Times New Roman" SIZE="2">10.2</FONT></TD>
<TD VALIGN="bottom"><FONT SIZE="1">&nbsp;&nbsp;</FONT></TD>
<TD VALIGN="top"><FONT STYLE="font-family:Times New Roman" SIZE="2">Form of Lockup Agreement between certain stockholders of CECO Environmental Corp., dated April 21, 2013 (included as Annex C to the joint proxy statement/prospectus that is a part
of this registration statement)</FONT></TD></TR>
<TR>
<TD HEIGHT="8"></TD>
<TD HEIGHT="8" COLSPAN="2"></TD></TR>
<TR>
<TD VALIGN="top" NOWRAP><FONT STYLE="font-family:Times New Roman" SIZE="2">23.1</FONT></TD>
<TD VALIGN="bottom"><FONT SIZE="1">&nbsp;&nbsp;</FONT></TD>
<TD VALIGN="top"><FONT STYLE="font-family:Times New Roman" SIZE="2">Consent of BDO USA, LLP**</FONT></TD></TR>
<TR>
<TD HEIGHT="8"></TD>
<TD HEIGHT="8" COLSPAN="2"></TD></TR>
<TR>
<TD VALIGN="top" NOWRAP><FONT STYLE="font-family:Times New Roman" SIZE="2">23.2</FONT></TD>
<TD VALIGN="bottom"><FONT SIZE="1">&nbsp;&nbsp;</FONT></TD>
<TD VALIGN="top"><FONT STYLE="font-family:Times New Roman" SIZE="2">Consent of BDO Audit &amp; Assurance B.V.**</FONT></TD></TR>
<TR>
<TD HEIGHT="8"></TD>
<TD HEIGHT="8" COLSPAN="2"></TD></TR>
<TR>
<TD VALIGN="top" NOWRAP><FONT STYLE="font-family:Times New Roman" SIZE="2">23.3</FONT></TD>
<TD VALIGN="bottom"><FONT SIZE="1">&nbsp;&nbsp;</FONT></TD>
<TD VALIGN="top"><FONT STYLE="font-family:Times New Roman" SIZE="2">Consent of Marcum LLP**</FONT></TD></TR>
<TR>
<TD HEIGHT="8"></TD>
<TD HEIGHT="8" COLSPAN="2"></TD></TR>
<TR>
<TD VALIGN="top" NOWRAP><FONT STYLE="font-family:Times New Roman" SIZE="2">23.4</FONT></TD>
<TD VALIGN="bottom"><FONT SIZE="1">&nbsp;&nbsp;</FONT></TD>
<TD VALIGN="top"><FONT STYLE="font-family:Times New Roman" SIZE="2">Awareness Letter of Marcum LLP**</FONT></TD></TR>
<TR>
<TD HEIGHT="8"></TD>
<TD HEIGHT="8" COLSPAN="2"></TD></TR>
<TR>
<TD VALIGN="top" NOWRAP><FONT STYLE="font-family:Times New Roman" SIZE="2">23.5</FONT></TD>
<TD VALIGN="bottom"><FONT SIZE="1">&nbsp;&nbsp;</FONT></TD>
<TD VALIGN="top"><FONT STYLE="font-family:Times New Roman" SIZE="2">Consents of Barnes &amp; Thornburg LLP (included in Exhibits 5.1** and 8.1**)</FONT></TD></TR>
<TR>
<TD HEIGHT="8"></TD>
<TD HEIGHT="8" COLSPAN="2"></TD></TR>
<TR>
<TD VALIGN="top" NOWRAP><FONT STYLE="font-family:Times New Roman" SIZE="2">23.6</FONT></TD>
<TD VALIGN="bottom"><FONT SIZE="1">&nbsp;&nbsp;</FONT></TD>
<TD VALIGN="top"><FONT STYLE="font-family:Times New Roman" SIZE="2">Consent of Fox Rothschild LLP (included in Exhibit 8.2**)</FONT></TD></TR>
<TR>
<TD HEIGHT="8"></TD>
<TD HEIGHT="8" COLSPAN="2"></TD></TR>
<TR>
<TD VALIGN="top" NOWRAP><FONT STYLE="font-family:Times New Roman" SIZE="2">23.7</FONT></TD>
<TD VALIGN="bottom"><FONT SIZE="1">&nbsp;&nbsp;</FONT></TD>
<TD VALIGN="top"><FONT STYLE="font-family:Times New Roman" SIZE="2">Consent of Barnes &amp; Thornburg LLP (included in Exhibit 8.3)</FONT></TD></TR>
<TR>
<TD HEIGHT="8"></TD>
<TD HEIGHT="8" COLSPAN="2"></TD></TR>
<TR>
<TD VALIGN="top" NOWRAP><FONT STYLE="font-family:Times New Roman" SIZE="2">23.8</FONT></TD>
<TD VALIGN="bottom"><FONT SIZE="1">&nbsp;&nbsp;</FONT></TD>
<TD VALIGN="top"><FONT STYLE="font-family:Times New Roman" SIZE="2">Consent of Fox Rothschild LLP (included in Exhibit 8.4)</FONT></TD></TR>
<TR>
<TD HEIGHT="8"></TD>
<TD HEIGHT="8" COLSPAN="2"></TD></TR>
<TR>
<TD VALIGN="top" NOWRAP><FONT STYLE="font-family:Times New Roman" SIZE="2">24.1</FONT></TD>
<TD VALIGN="bottom"><FONT SIZE="1">&nbsp;&nbsp;</FONT></TD>
<TD VALIGN="top"><FONT STYLE="font-family:Times New Roman" SIZE="2">Power of Attorney**</FONT></TD></TR>
<TR>
<TD HEIGHT="8"></TD>
<TD HEIGHT="8" COLSPAN="2"></TD></TR>
<TR>
<TD VALIGN="top" NOWRAP><FONT STYLE="font-family:Times New Roman" SIZE="2">99.1</FONT></TD>
<TD VALIGN="bottom"><FONT SIZE="1">&nbsp;&nbsp;</FONT></TD>
<TD VALIGN="top"><FONT STYLE="font-family:Times New Roman" SIZE="2">Form of Proxy Card for CECO Environmental Corp.**</FONT></TD></TR>
<TR>
<TD HEIGHT="8"></TD>
<TD HEIGHT="8" COLSPAN="2"></TD></TR>
<TR>
<TD VALIGN="top" NOWRAP><FONT STYLE="font-family:Times New Roman" SIZE="2">99.2</FONT></TD>
<TD VALIGN="bottom"><FONT SIZE="1">&nbsp;&nbsp;</FONT></TD>
<TD VALIGN="top"><FONT STYLE="font-family:Times New Roman" SIZE="2">Form of Proxy Card for Met-Pro Corporation**</FONT></TD></TR>
<TR>
<TD HEIGHT="8"></TD>
<TD HEIGHT="8" COLSPAN="2"></TD></TR>
<TR>
<TD VALIGN="top" NOWRAP><FONT STYLE="font-family:Times New Roman" SIZE="2">99.3</FONT></TD>
<TD VALIGN="bottom"><FONT SIZE="1">&nbsp;&nbsp;</FONT></TD>
<TD VALIGN="top"><FONT STYLE="font-family:Times New Roman" SIZE="2">Form of Election Form**</FONT></TD></TR>
<TR>
<TD HEIGHT="8"></TD>
<TD HEIGHT="8" COLSPAN="2"></TD></TR>
<TR>
<TD VALIGN="top" NOWRAP><FONT STYLE="font-family:Times New Roman" SIZE="2">99.4</FONT></TD>
<TD VALIGN="bottom"><FONT SIZE="1">&nbsp;&nbsp;</FONT></TD>
<TD VALIGN="top"><FONT STYLE="font-family:Times New Roman" SIZE="2">Consent of William Blair &amp; Company, L.L.C.**</FONT></TD></TR>
<TR>
<TD HEIGHT="8"></TD>
<TD HEIGHT="8" COLSPAN="2"></TD></TR>
<TR>
<TD VALIGN="top" NOWRAP><FONT STYLE="font-family:Times New Roman" SIZE="2">99.5</FONT></TD>
<TD VALIGN="bottom"><FONT SIZE="1">&nbsp;&nbsp;</FONT></TD>
<TD VALIGN="top"><FONT STYLE="font-family:Times New Roman" SIZE="2">Consent of Jefferies LLC**</FONT></TD></TR>
</TABLE> <P STYLE="font-size:12px;margin-top:0px;margin-bottom:0px">&nbsp;</P>
<TABLE STYLE="BORDER-COLLAPSE:COLLAPSE" BORDER="0" CELLPADDING="0" CELLSPACING="0" WIDTH="100%">
<TR>
<TD WIDTH="4%" VALIGN="top" ALIGN="left"><FONT STYLE="font-family:Times New Roman" SIZE="2">*</FONT></TD>
<TD ALIGN="left" VALIGN="top"><FONT STYLE="font-family:Times New Roman" SIZE="2">Schedules and exhibits have been omitted pursuant to item 601(b)(2) of Regulation S-K. The Registrant agrees to furnish supplementally to the Securities and Exchange
Commission a copy of any omitted schedule or exhibit upon request. </FONT></TD></TR></TABLE>
<TABLE STYLE="BORDER-COLLAPSE:COLLAPSE" BORDER="0" CELLPADDING="0" CELLSPACING="0" WIDTH="100%">
<TR>
<TD WIDTH="4%" VALIGN="top" ALIGN="left"><FONT STYLE="font-family:Times New Roman" SIZE="2">**</FONT></TD>
<TD ALIGN="left" VALIGN="top"><FONT STYLE="font-family:Times New Roman" SIZE="2">Previously filed. </FONT></TD></TR></TABLE>

<p Style='page-break-before:always'>
<HR  SIZE="3" style="COLOR:#999999" WIDTH="100%" ALIGN="CENTER">

 <P STYLE="margin-top:0px;margin-bottom:0px" ALIGN="center"><FONT STYLE="font-family:Times New Roman" SIZE="2"><B>SIGNATURES </B></FONT></P> <P STYLE="margin-top:12px;margin-bottom:0px"><FONT
STYLE="font-family:Times New Roman" SIZE="2">Pursuant to the requirements of the Securities Act, the registrant has duly caused this registration statement to be signed on its behalf by the undersigned, thereunto duly authorized, in the City of
Cincinnati, State of Ohio, on the 28th day of August, 2013. </FONT></P> <P STYLE="font-size:12px;margin-top:0px;margin-bottom:0px">&nbsp;</P><DIV ALIGN="right">
<TABLE CELLSPACING="0" CELLPADDING="0" WIDTH="40%" BORDER="0" STYLE="BORDER-COLLAPSE:COLLAPSE">


<TR>
<TD WIDTH="6%"></TD>
<TD VALIGN="bottom" WIDTH="2%"></TD>
<TD WIDTH="92%"></TD></TR>


<TR>
<TD VALIGN="top" COLSPAN="3"><FONT STYLE="font-family:Times New Roman" SIZE="2">CECO ENVIRONMENTAL CORP.</FONT></TD></TR>
<TR>
<TD HEIGHT="16"></TD>
<TD HEIGHT="16" COLSPAN="2"></TD></TR>
<TR>
<TD VALIGN="top"><FONT STYLE="font-family:Times New Roman" SIZE="2">By:</FONT></TD>
<TD VALIGN="bottom"><FONT SIZE="1">&nbsp;</FONT></TD>
<TD VALIGN="bottom"> <P STYLE="margin-top:0px;margin-bottom:1px;border-bottom:1px solid #000000"><FONT STYLE="font-family:Times New Roman" SIZE="2">/s/ Jeffrey Lang</FONT></P></TD></TR>
<TR>
<TD VALIGN="top"></TD>
<TD VALIGN="bottom"><FONT SIZE="1">&nbsp;</FONT></TD>
<TD VALIGN="bottom"><FONT STYLE="font-family:Times New Roman" SIZE="2">Jeffrey Lang</FONT></TD></TR>
<TR>
<TD VALIGN="top"></TD>
<TD VALIGN="bottom"><FONT SIZE="1">&nbsp;</FONT></TD>
<TD VALIGN="bottom"><FONT STYLE="font-family:Times New Roman" SIZE="2">Chief Executive Officer</FONT></TD></TR>
</TABLE></DIV> <P STYLE="margin-top:12px;margin-bottom:0px"><FONT STYLE="font-family:Times New Roman" SIZE="2">Pursuant to the requirements of the Securities Act of 1933, this registration statement has been signed by the
following persons in the capacities and on the dates indicated. </FONT></P> <P STYLE="font-size:12px;margin-top:0px;margin-bottom:0px">&nbsp;</P>
<TABLE CELLSPACING="0" CELLPADDING="0" WIDTH="100%" BORDER="0" STYLE="BORDER-COLLAPSE:COLLAPSE">


<TR>
<TD WIDTH="37%"></TD>
<TD VALIGN="bottom" WIDTH="1%"></TD>
<TD WIDTH="44%"></TD>
<TD VALIGN="bottom" WIDTH="2%"></TD>
<TD WIDTH="15%"></TD></TR>
<TR>
<TD VALIGN="bottom" NOWRAP ALIGN="center" STYLE="border-bottom:1px solid #000000"> <P STYLE="margin-top:0px;margin-bottom:1px" ALIGN="center"><FONT STYLE="font-family:Times New Roman" SIZE="1"><B>Signature</B></FONT></P></TD>
<TD VALIGN="bottom"><FONT SIZE="1">&nbsp;&nbsp;</FONT></TD>
<TD VALIGN="bottom" NOWRAP ALIGN="center" STYLE="border-bottom:1px solid #000000"> <P STYLE="margin-top:0px;margin-bottom:1px" ALIGN="center"><FONT STYLE="font-family:Times New Roman" SIZE="1"><B>Title</B></FONT></P></TD>
<TD VALIGN="bottom"><FONT SIZE="1">&nbsp;</FONT></TD>
<TD VALIGN="bottom" NOWRAP ALIGN="center" STYLE="border-bottom:1px solid #000000"> <P STYLE="margin-top:0px;margin-bottom:1px" ALIGN="center"><FONT STYLE="font-family:Times New Roman" SIZE="1"><B>Date</B></FONT></P></TD></TR>


<TR>
<TD HEIGHT="16"></TD>
<TD HEIGHT="16" COLSPAN="2"></TD>
<TD HEIGHT="16" COLSPAN="2"></TD></TR>
<TR>
<TD VALIGN="top"> <P STYLE="margin-top:0px;margin-bottom:0px;border-bottom:1px solid #000000"><FONT STYLE="font-family:Times New Roman" SIZE="2">/s/ Jeffrey Lang</FONT></P> <P STYLE="margin-top:0px;margin-bottom:1px"><FONT
STYLE="font-family:Times New Roman" SIZE="2">Jeffrey Lang</FONT></P></TD>
<TD VALIGN="bottom"><FONT SIZE="1">&nbsp;&nbsp;</FONT></TD>
<TD VALIGN="top" ALIGN="center"><FONT STYLE="font-family:Times New Roman" SIZE="2">Principal Executive Officer and Director</FONT></TD>
<TD VALIGN="bottom"><FONT SIZE="1">&nbsp;</FONT></TD>
<TD VALIGN="top" ALIGN="center"><FONT STYLE="font-family:Times New Roman" SIZE="2">August&nbsp;28, 2013</FONT></TD></TR>
<TR>
<TD HEIGHT="16"></TD>
<TD HEIGHT="16" COLSPAN="2"></TD>
<TD HEIGHT="16" COLSPAN="2"></TD></TR>
<TR>
<TD VALIGN="top"> <P STYLE="margin-top:0px;margin-bottom:0px;border-bottom:1px solid #000000"><FONT STYLE="font-family:Times New Roman" SIZE="2">*</FONT></P> <P STYLE="margin-top:0px;margin-bottom:1px"><FONT
STYLE="font-family:Times New Roman" SIZE="2">Benton L. Cook</FONT></P></TD>
<TD VALIGN="bottom"><FONT SIZE="1">&nbsp;&nbsp;</FONT></TD>
<TD VALIGN="top" ALIGN="center"><FONT STYLE="font-family:Times New Roman" SIZE="2">Principal Financial Officer and Controller</FONT></TD>
<TD VALIGN="bottom"><FONT SIZE="1">&nbsp;</FONT></TD>
<TD VALIGN="top" ALIGN="center"><FONT STYLE="font-family:Times New Roman" SIZE="2">August&nbsp;28, 2013</FONT></TD></TR>
<TR>
<TD HEIGHT="16"></TD>
<TD HEIGHT="16" COLSPAN="2"></TD>
<TD HEIGHT="16" COLSPAN="2"></TD></TR>
<TR>
<TD VALIGN="top"> <P STYLE="margin-top:0px;margin-bottom:0px;border-bottom:1px solid #000000"><FONT STYLE="font-family:Times New Roman" SIZE="2">*</FONT></P> <P STYLE="margin-top:0px;margin-bottom:1px"><FONT
STYLE="font-family:Times New Roman" SIZE="2">Jason DeZwirek</FONT></P></TD>
<TD VALIGN="bottom"><FONT SIZE="1">&nbsp;&nbsp;</FONT></TD>
<TD VALIGN="top" ALIGN="center"><FONT STYLE="font-family:Times New Roman" SIZE="2">Chairman of the Board and Director</FONT></TD>
<TD VALIGN="bottom"><FONT SIZE="1">&nbsp;</FONT></TD>
<TD VALIGN="top" ALIGN="center"><FONT STYLE="font-family:Times New Roman" SIZE="2">August&nbsp;28, 2013</FONT></TD></TR>
<TR>
<TD HEIGHT="16"></TD>
<TD HEIGHT="16" COLSPAN="2"></TD>
<TD HEIGHT="16" COLSPAN="2"></TD></TR>
<TR>
<TD VALIGN="top"> <P STYLE="margin-top:0px;margin-bottom:0px;border-bottom:1px solid #000000"><FONT STYLE="font-family:Times New Roman" SIZE="2">*</FONT></P> <P STYLE="margin-top:0px;margin-bottom:1px"><FONT
STYLE="font-family:Times New Roman" SIZE="2">Arthur Cape</FONT></P></TD>
<TD VALIGN="bottom"><FONT SIZE="1">&nbsp;&nbsp;</FONT></TD>
<TD VALIGN="top" ALIGN="center"><FONT STYLE="font-family:Times New Roman" SIZE="2">Director</FONT></TD>
<TD VALIGN="bottom"><FONT SIZE="1">&nbsp;</FONT></TD>
<TD VALIGN="top" ALIGN="center"><FONT STYLE="font-family:Times New Roman" SIZE="2">August&nbsp;28, 2013</FONT></TD></TR>
<TR>
<TD HEIGHT="16"></TD>
<TD HEIGHT="16" COLSPAN="2"></TD>
<TD HEIGHT="16" COLSPAN="2"></TD></TR>
<TR>
<TD VALIGN="top"> <P STYLE="margin-top:0px;margin-bottom:0px;border-bottom:1px solid #000000"><FONT STYLE="font-family:Times New Roman" SIZE="2">*</FONT></P> <P STYLE="margin-top:0px;margin-bottom:1px"><FONT
STYLE="font-family:Times New Roman" SIZE="2">Eric M. Goldberg</FONT></P></TD>
<TD VALIGN="bottom"><FONT SIZE="1">&nbsp;&nbsp;</FONT></TD>
<TD VALIGN="top" ALIGN="center"><FONT STYLE="font-family:Times New Roman" SIZE="2">Director</FONT></TD>
<TD VALIGN="bottom"><FONT SIZE="1">&nbsp;</FONT></TD>
<TD VALIGN="top" ALIGN="center"><FONT STYLE="font-family:Times New Roman" SIZE="2">August&nbsp;28, 2013</FONT></TD></TR>
<TR>
<TD HEIGHT="16"></TD>
<TD HEIGHT="16" COLSPAN="2"></TD>
<TD HEIGHT="16" COLSPAN="2"></TD></TR>
<TR>
<TD VALIGN="top"> <P STYLE="margin-top:0px;margin-bottom:0px;border-bottom:1px solid #000000"><FONT STYLE="font-family:Times New Roman" SIZE="2">*</FONT></P> <P STYLE="margin-top:0px;margin-bottom:1px"><FONT
STYLE="font-family:Times New Roman" SIZE="2">Ronald E. Krieg</FONT></P></TD>
<TD VALIGN="bottom"><FONT SIZE="1">&nbsp;&nbsp;</FONT></TD>
<TD VALIGN="top" ALIGN="center"><FONT STYLE="font-family:Times New Roman" SIZE="2">Director</FONT></TD>
<TD VALIGN="bottom"><FONT SIZE="1">&nbsp;</FONT></TD>
<TD VALIGN="top" ALIGN="center"><FONT STYLE="font-family:Times New Roman" SIZE="2">August&nbsp;28, 2013</FONT></TD></TR>
<TR>
<TD HEIGHT="16"></TD>
<TD HEIGHT="16" COLSPAN="2"></TD>
<TD HEIGHT="16" COLSPAN="2"></TD></TR>
<TR>
<TD VALIGN="top"> <P STYLE="margin-top:0px;margin-bottom:0px;border-bottom:1px solid #000000"><FONT STYLE="font-family:Times New Roman" SIZE="2">*</FONT></P> <P STYLE="margin-top:0px;margin-bottom:1px"><FONT
STYLE="font-family:Times New Roman" SIZE="2">Jonathan Pollack</FONT></P></TD>
<TD VALIGN="bottom"><FONT SIZE="1">&nbsp;&nbsp;</FONT></TD>
<TD VALIGN="top" ALIGN="center"><FONT STYLE="font-family:Times New Roman" SIZE="2">Director</FONT></TD>
<TD VALIGN="bottom"><FONT SIZE="1">&nbsp;</FONT></TD>
<TD VALIGN="top" ALIGN="center"><FONT STYLE="font-family:Times New Roman" SIZE="2">August&nbsp;28, 2013</FONT></TD></TR>
<TR>
<TD HEIGHT="16"></TD>
<TD HEIGHT="16" COLSPAN="2"></TD>
<TD HEIGHT="16" COLSPAN="2"></TD></TR>
<TR>
<TD VALIGN="top"> <P STYLE="margin-top:0px;margin-bottom:0px;border-bottom:1px solid #000000"><FONT STYLE="font-family:Times New Roman" SIZE="2">*</FONT></P> <P STYLE="margin-top:0px;margin-bottom:1px"><FONT
STYLE="font-family:Times New Roman" SIZE="2">Seth Rudin</FONT></P></TD>
<TD VALIGN="bottom"><FONT SIZE="1">&nbsp;&nbsp;</FONT></TD>
<TD VALIGN="top" ALIGN="center"><FONT STYLE="font-family:Times New Roman" SIZE="2">Director</FONT></TD>
<TD VALIGN="bottom"><FONT SIZE="1">&nbsp;</FONT></TD>
<TD VALIGN="top" ALIGN="center"><FONT STYLE="font-family:Times New Roman" SIZE="2">August&nbsp;28, 2013</FONT></TD></TR>
<TR>
<TD HEIGHT="16"></TD>
<TD HEIGHT="16" COLSPAN="2"></TD>
<TD HEIGHT="16" COLSPAN="2"></TD></TR>
<TR>
<TD VALIGN="top"> <P STYLE="margin-top:0px;margin-bottom:0px;border-bottom:1px solid #000000"><FONT STYLE="font-family:Times New Roman" SIZE="2">*</FONT></P> <P STYLE="margin-top:0px;margin-bottom:1px"><FONT
STYLE="font-family:Times New Roman" SIZE="2">Donald A. Wright</FONT></P></TD>
<TD VALIGN="bottom"><FONT SIZE="1">&nbsp;&nbsp;</FONT></TD>
<TD VALIGN="top" ALIGN="center"><FONT STYLE="font-family:Times New Roman" SIZE="2">Director</FONT></TD>
<TD VALIGN="bottom"><FONT SIZE="1">&nbsp;</FONT></TD>
<TD VALIGN="top" ALIGN="center"><FONT STYLE="font-family:Times New Roman" SIZE="2">August&nbsp;28, 2013</FONT></TD></TR>
</TABLE> <P STYLE="font-size:12px;margin-top:0px;margin-bottom:0px">&nbsp;</P>
<TABLE CELLSPACING="0" CELLPADDING="0" WIDTH="40%" BORDER="0" STYLE="BORDER-COLLAPSE:COLLAPSE">


<TR>
<TD WIDTH="10%"></TD>
<TD VALIGN="bottom" WIDTH="2%"></TD>
<TD WIDTH="88%"></TD></TR>


<TR>
<TD VALIGN="top"><FONT STYLE="font-family:Times New Roman" SIZE="2">*&nbsp;By:</FONT></TD>
<TD VALIGN="bottom"><FONT SIZE="1">&nbsp;</FONT></TD>
<TD VALIGN="bottom"> <P STYLE="margin-top:0px;margin-bottom:1px;border-bottom:1px solid #000000"><FONT STYLE="font-family:Times New Roman" SIZE="2">/s/ Jeffrey Lang</FONT></P></TD></TR>
<TR>
<TD VALIGN="top"></TD>
<TD VALIGN="bottom"><FONT SIZE="1">&nbsp;</FONT></TD>
<TD VALIGN="bottom"><FONT STYLE="font-family:Times New Roman" SIZE="2">Jeffrey Lang, Attorney in Fact</FONT></TD></TR>
</TABLE>

<p Style='page-break-before:always'>
<HR  SIZE="3" style="COLOR:#999999" WIDTH="100%" ALIGN="CENTER">

 <P STYLE="margin-top:0px;margin-bottom:0px" ALIGN="center"><FONT STYLE="font-family:Times New Roman" SIZE="2"><B>Exhibit Index </B></FONT></P>
<P STYLE="font-size:12px;margin-top:0px;margin-bottom:0px">&nbsp;</P>
<TABLE CELLSPACING="0" CELLPADDING="0" WIDTH="100%" BORDER="0" STYLE="BORDER-COLLAPSE:COLLAPSE" ALIGN="center">


<TR>
<TD></TD>
<TD VALIGN="bottom" WIDTH="5%"></TD>
<TD WIDTH="92%"></TD></TR>
<TR>
<TD VALIGN="bottom" NOWRAP ALIGN="center"> <P STYLE="border-bottom:1px solid #000000;width:28pt" ALIGN="center"><FONT STYLE="font-family:Times New Roman" SIZE="1"><B>Exhibits</B></FONT></P></TD>
<TD VALIGN="bottom"><FONT SIZE="1">&nbsp;&nbsp;</FONT></TD>
<TD VALIGN="bottom">&nbsp;<FONT SIZE="1">&nbsp;</FONT></TD></TR>


<TR>
<TD HEIGHT="8"></TD>
<TD HEIGHT="8" COLSPAN="2"></TD></TR>
<TR>
<TD VALIGN="top" NOWRAP><FONT STYLE="font-family:Times New Roman" SIZE="2">&nbsp;&nbsp;2.1</FONT></TD>
<TD VALIGN="bottom"><FONT SIZE="1">&nbsp;&nbsp;</FONT></TD>
<TD VALIGN="top"><FONT STYLE="font-family:Times New Roman" SIZE="2">Agreement and Plan of Merger by and among Met-Pro Corporation, CECO Environmental Corp., Mustang Acquisition Inc. and Mustang Acquisition II Inc., dated as of April 21, 2013
(included as Annex A to the joint proxy statement/prospectus that is a part of this registration statement)*</FONT></TD></TR>
<TR>
<TD HEIGHT="8"></TD>
<TD HEIGHT="8" COLSPAN="2"></TD></TR>
<TR>
<TD VALIGN="top" NOWRAP><FONT STYLE="font-family:Times New Roman" SIZE="2">&nbsp;&nbsp;2.2</FONT></TD>
<TD VALIGN="bottom"><FONT SIZE="1">&nbsp;&nbsp;</FONT></TD>
<TD VALIGN="top"><FONT STYLE="font-family:Times New Roman" SIZE="2">Amendment No. 1 to Agreement and Plan of Merger by and among Met-Pro Corporation, CECO Environmental Corp., Mustang Acquisition Inc. and Mustang Acquisition II LLC (formerly known
as Mustang Acquisition II Inc.), dated as of August 5, 2013 (incorporated by reference to Exhibit 2.1 to the Form 8-K filed by CECO Environmental Corp. on August 8, 2013)</FONT></TD></TR>
<TR>
<TD HEIGHT="8"></TD>
<TD HEIGHT="8" COLSPAN="2"></TD></TR>
<TR>
<TD VALIGN="top" NOWRAP><FONT STYLE="font-family:Times New Roman" SIZE="2">&nbsp;&nbsp;5.1</FONT></TD>
<TD VALIGN="bottom"><FONT SIZE="1">&nbsp;&nbsp;</FONT></TD>
<TD VALIGN="top"><FONT STYLE="font-family:Times New Roman" SIZE="2">Opinion of Barnes &amp; Thornburg LLP, regarding the legality of the securities being issued**</FONT></TD></TR>
<TR>
<TD HEIGHT="8"></TD>
<TD HEIGHT="8" COLSPAN="2"></TD></TR>
<TR>
<TD VALIGN="top" NOWRAP><FONT STYLE="font-family:Times New Roman" SIZE="2">&nbsp;&nbsp;8.1</FONT></TD>
<TD VALIGN="bottom"><FONT SIZE="1">&nbsp;&nbsp;</FONT></TD>
<TD VALIGN="top"><FONT STYLE="font-family:Times New Roman" SIZE="2">Opinion of Barnes &amp; Thornburg LLP, regarding certain tax matters**</FONT></TD></TR>
<TR>
<TD HEIGHT="8"></TD>
<TD HEIGHT="8" COLSPAN="2"></TD></TR>
<TR>
<TD VALIGN="top" NOWRAP><FONT STYLE="font-family:Times New Roman" SIZE="2">&nbsp;&nbsp;8.2</FONT></TD>
<TD VALIGN="bottom"><FONT SIZE="1">&nbsp;&nbsp;</FONT></TD>
<TD VALIGN="top"><FONT STYLE="font-family:Times New Roman" SIZE="2">Opinion of Fox Rothschild LLP, regarding certain tax matters**</FONT></TD></TR>
<TR>
<TD HEIGHT="8"></TD>
<TD HEIGHT="8" COLSPAN="2"></TD></TR>
<TR>
<TD VALIGN="top" NOWRAP><FONT STYLE="font-family:Times New Roman" SIZE="2">&nbsp;&nbsp;8.3</FONT></TD>
<TD VALIGN="bottom"><FONT SIZE="1">&nbsp;&nbsp;</FONT></TD>
<TD VALIGN="top"><FONT STYLE="font-family:Times New Roman" SIZE="2">Opinion of Barnes &amp; Thornburg LLP, regarding U.S. tax matters (delivered to CECO Environmental Corp. at the closing of the mergers)</FONT></TD></TR>
<TR>
<TD HEIGHT="8"></TD>
<TD HEIGHT="8" COLSPAN="2"></TD></TR>
<TR>
<TD VALIGN="top" NOWRAP><FONT STYLE="font-family:Times New Roman" SIZE="2">&nbsp;&nbsp;8.4</FONT></TD>
<TD VALIGN="bottom"><FONT SIZE="1">&nbsp;&nbsp;</FONT></TD>
<TD VALIGN="top"><FONT STYLE="font-family:Times New Roman" SIZE="2">Opinion of Fox Rothschild LLP, regarding U.S. tax matters (delivered to Met-Pro Corporation at the closing of the mergers)</FONT></TD></TR>
<TR>
<TD HEIGHT="8"></TD>
<TD HEIGHT="8" COLSPAN="2"></TD></TR>
<TR>
<TD VALIGN="top" NOWRAP><FONT STYLE="font-family:Times New Roman" SIZE="2">10.1</FONT></TD>
<TD VALIGN="bottom"><FONT SIZE="1">&nbsp;&nbsp;</FONT></TD>
<TD VALIGN="top"><FONT STYLE="font-family:Times New Roman" SIZE="2">Voting Agreement of Icarus Investment Corp., Phillip DeZwirek and Jason DeZwirek, dated April 21, 2013 (included as Annex B to the joint proxy statement/prospectus that is a part of
this registration statement)</FONT></TD></TR>
<TR>
<TD HEIGHT="8"></TD>
<TD HEIGHT="8" COLSPAN="2"></TD></TR>
<TR>
<TD VALIGN="top" NOWRAP><FONT STYLE="font-family:Times New Roman" SIZE="2">10.2</FONT></TD>
<TD VALIGN="bottom"><FONT SIZE="1">&nbsp;&nbsp;</FONT></TD>
<TD VALIGN="top"><FONT STYLE="font-family:Times New Roman" SIZE="2">Form of Lockup Agreement between certain stockholders of CECO Environmental Corp., dated April 21, 2013 (included as Annex C to the joint proxy statement/prospectus that is a part
of this registration statement)</FONT></TD></TR>
<TR>
<TD HEIGHT="8"></TD>
<TD HEIGHT="8" COLSPAN="2"></TD></TR>
<TR>
<TD VALIGN="top" NOWRAP><FONT STYLE="font-family:Times New Roman" SIZE="2">23.1</FONT></TD>
<TD VALIGN="bottom"><FONT SIZE="1">&nbsp;&nbsp;</FONT></TD>
<TD VALIGN="top"><FONT STYLE="font-family:Times New Roman" SIZE="2">Consent of BDO USA, LLP**</FONT></TD></TR>
<TR>
<TD HEIGHT="8"></TD>
<TD HEIGHT="8" COLSPAN="2"></TD></TR>
<TR>
<TD VALIGN="top" NOWRAP><FONT STYLE="font-family:Times New Roman" SIZE="2">23.2</FONT></TD>
<TD VALIGN="bottom"><FONT SIZE="1">&nbsp;&nbsp;</FONT></TD>
<TD VALIGN="top"><FONT STYLE="font-family:Times New Roman" SIZE="2">Consent of BDO Audit &amp; Assurance B.V.**</FONT></TD></TR>
<TR>
<TD HEIGHT="8"></TD>
<TD HEIGHT="8" COLSPAN="2"></TD></TR>
<TR>
<TD VALIGN="top" NOWRAP><FONT STYLE="font-family:Times New Roman" SIZE="2">23.3</FONT></TD>
<TD VALIGN="bottom"><FONT SIZE="1">&nbsp;&nbsp;</FONT></TD>
<TD VALIGN="top"><FONT STYLE="font-family:Times New Roman" SIZE="2">Consent of Marcum LLP**</FONT></TD></TR>
<TR>
<TD HEIGHT="8"></TD>
<TD HEIGHT="8" COLSPAN="2"></TD></TR>
<TR>
<TD VALIGN="top" NOWRAP><FONT STYLE="font-family:Times New Roman" SIZE="2">23.4</FONT></TD>
<TD VALIGN="bottom"><FONT SIZE="1">&nbsp;&nbsp;</FONT></TD>
<TD VALIGN="top"><FONT STYLE="font-family:Times New Roman" SIZE="2">Awareness Letter of Marcum LLP**</FONT></TD></TR>
<TR>
<TD HEIGHT="8"></TD>
<TD HEIGHT="8" COLSPAN="2"></TD></TR>
<TR>
<TD VALIGN="top" NOWRAP><FONT STYLE="font-family:Times New Roman" SIZE="2">23.5</FONT></TD>
<TD VALIGN="bottom"><FONT SIZE="1">&nbsp;&nbsp;</FONT></TD>
<TD VALIGN="top"><FONT STYLE="font-family:Times New Roman" SIZE="2">Consents of Barnes &amp; Thornburg LLP (included in Exhibits 5.1** and 8.1**)</FONT></TD></TR>
<TR>
<TD HEIGHT="8"></TD>
<TD HEIGHT="8" COLSPAN="2"></TD></TR>
<TR>
<TD VALIGN="top" NOWRAP><FONT STYLE="font-family:Times New Roman" SIZE="2">23.6</FONT></TD>
<TD VALIGN="bottom"><FONT SIZE="1">&nbsp;&nbsp;</FONT></TD>
<TD VALIGN="top"><FONT STYLE="font-family:Times New Roman" SIZE="2">Consent of Fox Rothschild LLP (included in Exhibit 8.2**)</FONT></TD></TR>
<TR>
<TD HEIGHT="8"></TD>
<TD HEIGHT="8" COLSPAN="2"></TD></TR>
<TR>
<TD VALIGN="top" NOWRAP><FONT STYLE="font-family:Times New Roman" SIZE="2">23.7</FONT></TD>
<TD VALIGN="bottom"><FONT SIZE="1">&nbsp;&nbsp;</FONT></TD>
<TD VALIGN="top"><FONT STYLE="font-family:Times New Roman" SIZE="2">Consent of Barnes &amp; Thornburg LLP (included in Exhibit 8.3)</FONT></TD></TR>
<TR>
<TD HEIGHT="8"></TD>
<TD HEIGHT="8" COLSPAN="2"></TD></TR>
<TR>
<TD VALIGN="top" NOWRAP><FONT STYLE="font-family:Times New Roman" SIZE="2">23.8</FONT></TD>
<TD VALIGN="bottom"><FONT SIZE="1">&nbsp;&nbsp;</FONT></TD>
<TD VALIGN="top"><FONT STYLE="font-family:Times New Roman" SIZE="2">Consent of Fox Rothschild LLP (included in Exhibit 8.4)</FONT></TD></TR>
<TR>
<TD HEIGHT="8"></TD>
<TD HEIGHT="8" COLSPAN="2"></TD></TR>
<TR>
<TD VALIGN="top" NOWRAP><FONT STYLE="font-family:Times New Roman" SIZE="2">24.1</FONT></TD>
<TD VALIGN="bottom"><FONT SIZE="1">&nbsp;&nbsp;</FONT></TD>
<TD VALIGN="top"><FONT STYLE="font-family:Times New Roman" SIZE="2">Power of Attorney**</FONT></TD></TR>
<TR>
<TD HEIGHT="8"></TD>
<TD HEIGHT="8" COLSPAN="2"></TD></TR>
<TR>
<TD VALIGN="top" NOWRAP><FONT STYLE="font-family:Times New Roman" SIZE="2">99.1</FONT></TD>
<TD VALIGN="bottom"><FONT SIZE="1">&nbsp;&nbsp;</FONT></TD>
<TD VALIGN="top"><FONT STYLE="font-family:Times New Roman" SIZE="2">Form of Proxy Card for CECO Environmental Corp.**</FONT></TD></TR>
<TR>
<TD HEIGHT="8"></TD>
<TD HEIGHT="8" COLSPAN="2"></TD></TR>
<TR>
<TD VALIGN="top" NOWRAP><FONT STYLE="font-family:Times New Roman" SIZE="2">99.2</FONT></TD>
<TD VALIGN="bottom"><FONT SIZE="1">&nbsp;&nbsp;</FONT></TD>
<TD VALIGN="top"><FONT STYLE="font-family:Times New Roman" SIZE="2">Form of Proxy Card for Met-Pro Corporation**</FONT></TD></TR>
<TR>
<TD HEIGHT="8"></TD>
<TD HEIGHT="8" COLSPAN="2"></TD></TR>
<TR>
<TD VALIGN="top" NOWRAP><FONT STYLE="font-family:Times New Roman" SIZE="2">99.3</FONT></TD>
<TD VALIGN="bottom"><FONT SIZE="1">&nbsp;&nbsp;</FONT></TD>
<TD VALIGN="top"><FONT STYLE="font-family:Times New Roman" SIZE="2">Form of Election Form**</FONT></TD></TR>
<TR>
<TD HEIGHT="8"></TD>
<TD HEIGHT="8" COLSPAN="2"></TD></TR>
<TR>
<TD VALIGN="top" NOWRAP><FONT STYLE="font-family:Times New Roman" SIZE="2">99.4</FONT></TD>
<TD VALIGN="bottom"><FONT SIZE="1">&nbsp;&nbsp;</FONT></TD>
<TD VALIGN="top"><FONT STYLE="font-family:Times New Roman" SIZE="2">Consent of William Blair &amp; Company, L.L.C.**</FONT></TD></TR>
<TR>
<TD HEIGHT="8"></TD>
<TD HEIGHT="8" COLSPAN="2"></TD></TR>
<TR>
<TD VALIGN="top" NOWRAP><FONT STYLE="font-family:Times New Roman" SIZE="2">99.5</FONT></TD>
<TD VALIGN="bottom"><FONT SIZE="1">&nbsp;&nbsp;</FONT></TD>
<TD VALIGN="top"><FONT STYLE="font-family:Times New Roman" SIZE="2">Consent of Jefferies LLC**</FONT></TD></TR>
</TABLE> <P STYLE="font-size:12px;margin-top:0px;margin-bottom:0px">&nbsp;</P>
<TABLE STYLE="BORDER-COLLAPSE:COLLAPSE" BORDER="0" CELLPADDING="0" CELLSPACING="0" WIDTH="100%">
<TR>
<TD WIDTH="4%" VALIGN="top" ALIGN="left"><FONT STYLE="font-family:Times New Roman" SIZE="2">*</FONT></TD>
<TD ALIGN="left" VALIGN="top"><FONT STYLE="font-family:Times New Roman" SIZE="2">Schedules and exhibits have been omitted pursuant to item 601(b)(2) of Regulation S-K. The Registrant agrees to furnish supplementally to the Securities and Exchange
Commission a copy of any omitted schedule or exhibit upon request. </FONT></TD></TR></TABLE>
<TABLE STYLE="BORDER-COLLAPSE:COLLAPSE" BORDER="0" CELLPADDING="0" CELLSPACING="0" WIDTH="100%">
<TR>
<TD WIDTH="4%" VALIGN="top" ALIGN="left"><FONT STYLE="font-family:Times New Roman" SIZE="2">**</FONT></TD>
<TD ALIGN="left" VALIGN="top"><FONT STYLE="font-family:Times New Roman" SIZE="2">Previously filed. </FONT></TD></TR></TABLE>
</BODY></HTML>
</TEXT>
</DOCUMENT>
<DOCUMENT>
<TYPE>EX-8.3
<SEQUENCE>2
<FILENAME>d589759dex83.htm
<DESCRIPTION>EX-8.3
<TEXT>
<HTML><HEAD>
<TITLE>EX-8.3</TITLE>
</HEAD>
 <BODY BGCOLOR="WHITE">

 <P STYLE="margin-top:0px;margin-bottom:0px" ALIGN="right"><FONT STYLE="font-family:Times New Roman" SIZE="2"><B>Exhibit 8.3 </B></FONT></P> <P STYLE="margin-top:12px;margin-bottom:0px" ALIGN="right"><FONT
STYLE="font-family:Times New Roman" SIZE="2">August&nbsp;27, 2013 </FONT></P> <P STYLE="margin-top:12px;margin-bottom:0px"><FONT STYLE="font-family:Times New Roman" SIZE="2">CECO Environmental Corp. </FONT></P>
<P STYLE="margin-top:0px;margin-bottom:0px"><FONT STYLE="font-family:Times New Roman" SIZE="2">4625 Red Bank Road, Suite 200 </FONT></P> <P STYLE="margin-top:0px;margin-bottom:0px"><FONT STYLE="font-family:Times New Roman" SIZE="2">Cincinnati, OH
45227 </FONT></P> <P STYLE="margin-top:12px;margin-bottom:0px"><FONT STYLE="font-family:Times New Roman" SIZE="2">Ladies and Gentleman: </FONT></P> <P STYLE="margin-top:12px;margin-bottom:0px; text-indent:4%"><FONT
STYLE="font-family:Times New Roman" SIZE="2">We have acted as counsel to CECO Environmental Corp., a Delaware corporation (&#147;Parent&#148;), in connection with the mergers pursuant to the Agreement and Plan of Merger (the &#147;Agreement&#148;),
dated as of April&nbsp;21, 2013, and amended as of August&nbsp;5, 2013, by and among Parent, Mustang Acquisition, Inc., a Delaware corporation (&#147;Merger Sub&#148;), Mustang Acquisition II, Inc. (predecessor of Mustang Acquisition II LLC), a
Delaware corporation (&#147;Successor Sub&#148;), and Met-Pro Corporation, a Pennsylvania corporation (the &#147;Company&#148;), in which Merger Sub will be merged with and into the Company, with the Company as the surviving entity (the
&#147;Merger&#148;), following which the Company will be merged with and into Successor Sub (LLC), with Successor Sub (LLC) as the surviving entity, the sole member of which will be Parent (the &#147;Second Step Merger&#148;, and, together with the
Merger, the &#147;Reorganization&#148;). This opinion is furnished to you pursuant to Section&nbsp;7.12 of the Agreement. </FONT></P> <P STYLE="margin-top:12px;margin-bottom:0px; text-indent:4%"><FONT STYLE="font-family:Times New Roman" SIZE="2">For
purposes of this opinion, we have examined and relied upon the registration statement, including amendments, filed by Parent on Form S-4 (the &#147;Registration Statement&#148;) with the Securities and Exchange Commission (the
&#147;Commission&#148;) pursuant to the Securities Act of 1933, as amended (the &#147;Act&#148;); the Agreement; the letters provided to us and executed by the officers of both Parent and the Company dated August&nbsp;27, 2013, the contents of which
we assume are and will continue to be correct without regard to any qualification as to knowledge, intention or belief (the &#147;Tax Representation Letters&#148;); and such other documents as we have deemed necessary or appropriate, and we have
assumed, with your consent, the following: </FONT></P> <P STYLE="font-size:6px;margin-top:0px;margin-bottom:0px">&nbsp;</P>
<TABLE STYLE="BORDER-COLLAPSE:COLLAPSE" BORDER="0" CELLPADDING="0" CELLSPACING="0" WIDTH="100%">
<TR>
<TD WIDTH="4%"><FONT SIZE="1">&nbsp;</FONT></TD>
<TD WIDTH="4%" VALIGN="top" ALIGN="left"><FONT STYLE="font-family:Times New Roman" SIZE="2">1.</FONT></TD>
<TD ALIGN="left" VALIGN="top"><FONT STYLE="font-family:Times New Roman" SIZE="2">the representations contained in the Registration Statement, the Agreement, and the Tax Representation Letters and any other documents we reviewed were true, correct
and complete as of the effective times of the Merger and the Second Step Merger; </FONT></TD></TR></TABLE> <P STYLE="font-size:6px;margin-top:0px;margin-bottom:0px">&nbsp;</P>
<TABLE STYLE="BORDER-COLLAPSE:COLLAPSE" BORDER="0" CELLPADDING="0" CELLSPACING="0" WIDTH="100%">
<TR>
<TD WIDTH="4%"><FONT SIZE="1">&nbsp;</FONT></TD>
<TD WIDTH="4%" VALIGN="top" ALIGN="left"><FONT STYLE="font-family:Times New Roman" SIZE="2">2.</FONT></TD>
<TD ALIGN="left" VALIGN="top"><FONT STYLE="font-family:Times New Roman" SIZE="2">any and all obligations imposed by the Registration Statement, the Agreement and any other documents we reviewed have been or will be performed or satisfied in
accordance with their terms; and </FONT></TD></TR></TABLE> <P STYLE="font-size:6px;margin-top:0px;margin-bottom:0px">&nbsp;</P>
<TABLE STYLE="BORDER-COLLAPSE:COLLAPSE" BORDER="0" CELLPADDING="0" CELLSPACING="0" WIDTH="100%">
<TR>
<TD WIDTH="4%"><FONT SIZE="1">&nbsp;</FONT></TD>
<TD WIDTH="4%" VALIGN="top" ALIGN="left"><FONT STYLE="font-family:Times New Roman" SIZE="2">3.</FONT></TD>
<TD ALIGN="left" VALIGN="top"><FONT STYLE="font-family:Times New Roman" SIZE="2">the Merger and the Second Step Merger, each at their respective effective times, were consummated pursuant to and in accordance with the terms of the Agreement and in
the manner described in the Registration Statement. </FONT></TD></TR></TABLE>

<p Style='page-break-before:always'>
<HR  SIZE="3" style="COLOR:#999999" WIDTH="100%" ALIGN="CENTER">

 <P STYLE="margin-top:0px;margin-bottom:0px"><FONT STYLE="font-family:Times New Roman" SIZE="2">CECO Environmental Corp. </FONT></P> <P STYLE="margin-top:0px;margin-bottom:0px"><FONT
STYLE="font-family:Times New Roman" SIZE="2">August&nbsp;27, 2013 </FONT></P> <P STYLE="margin-top:0px;margin-bottom:0px"><FONT STYLE="font-family:Times New Roman" SIZE="2">Page 2 </FONT></P>
<P STYLE="margin-top:12px;margin-bottom:0px; text-indent:4%"><FONT STYLE="font-family:Times New Roman" SIZE="2">Based upon and subject to the foregoing, and our consideration of such other matters of fact and law as we have considered necessary or
appropriate, it is our opinion, under presently applicable U.S. federal income tax law, that the Reorganization will be treated for U.S. federal income tax purposes as a reorganization within the meaning of Section&nbsp;368(a) of the Internal
Revenue Code of 1986, as amended (the &#147;Code&#148;), and Parent and the Company will each be a party to that reorganization, as contemplated by Section&nbsp;368(b) of the Code. </FONT></P>
<P STYLE="margin-top:12px;margin-bottom:0px; text-indent:4%"><FONT STYLE="font-family:Times New Roman" SIZE="2">This opinion is limited to the federal income tax laws of the United States and does not purport to discuss the consequences or
effectiveness of the Reorganization under any other laws. </FONT></P> <P STYLE="margin-top:12px;margin-bottom:0px; text-indent:4%"><FONT STYLE="font-family:Times New Roman" SIZE="2">We hereby consent to the filing of this opinion as an exhibit to
the Registration Statement. In giving such consent, we do not hereby concede that we are within the category of persons whose consent is required under Section&nbsp;7 of the Act or the rules and regulations of the Commission promulgated thereunder.
</FONT></P> <P STYLE="font-size:12px;margin-top:0px;margin-bottom:0px">&nbsp;</P><DIV ALIGN="right">
<TABLE CELLSPACING="0" CELLPADDING="0" WIDTH="40%" BORDER="0" STYLE="BORDER-COLLAPSE:COLLAPSE">


<TR>
<TD WIDTH="100%"></TD></TR>


<TR>
<TD VALIGN="top"> <P STYLE="margin-top:0px;margin-bottom:0px"><FONT STYLE="font-family:Times New Roman" SIZE="2">Very truly yours,</FONT></P> <P STYLE="font-size:12px;margin-top:0px;margin-bottom:0px">&nbsp;</P>
<P STYLE="margin-top:0px;margin-bottom:1px"><FONT STYLE="font-family:Times New Roman" SIZE="2">/s/ Barnes&nbsp;&amp; Thornburg LLP</FONT></P></TD></TR>
</TABLE></DIV>
</BODY></HTML>
</TEXT>
</DOCUMENT>
<DOCUMENT>
<TYPE>EX-8.4
<SEQUENCE>3
<FILENAME>d589759dex84.htm
<DESCRIPTION>EX-8.4
<TEXT>
<HTML><HEAD>
<TITLE>EX-8.4</TITLE>
</HEAD>
 <BODY BGCOLOR="WHITE">

 <P STYLE="margin-top:0px;margin-bottom:0px" ALIGN="right"><FONT STYLE="font-family:Times New Roman" SIZE="2"><B>Exhibit 8.4 </B></FONT></P> <P STYLE="margin-top:12px;margin-bottom:0px"><FONT
STYLE="font-family:Times New Roman" SIZE="2">August&nbsp;27, 2013 </FONT></P> <P STYLE="margin-top:12px;margin-bottom:0px"><FONT STYLE="font-family:Times New Roman" SIZE="2">Met-Pro Corporation </FONT></P>
<P STYLE="margin-top:0px;margin-bottom:0px"><FONT STYLE="font-family:Times New Roman" SIZE="2">160 Cassell Road </FONT></P> <P STYLE="margin-top:0px;margin-bottom:0px"><FONT STYLE="font-family:Times New Roman" SIZE="2">Harleysville, PA 19348
</FONT></P> <P STYLE="margin-top:12px;margin-bottom:0px"><FONT STYLE="font-family:Times New Roman" SIZE="2">Ladies and Gentlemen: </FONT></P> <P STYLE="margin-top:12px;margin-bottom:0px"><FONT STYLE="font-family:Times New Roman" SIZE="2">We have
acted as counsel to Met-Pro Corporation, a Pennsylvania corporation (the &#147;Company&#148;), in connection with the mergers pursuant to the Agreement and Plan of Merger (the &#147;Agreement&#148;), dated April&nbsp;21, 2013, and amended as of
August&nbsp;5, 2013, by and among the Company; Mustang Acquisition Inc., a Delaware corporation (&#147;Merger Sub&#148;); Mustang Acquisition II Inc. (predecessor of Mustang Acquisition II LLC), a Delaware corporation (&#147;Successor Sub&#148;);
and CECO Environmental Corp., a Delaware corporation (&#147;Parent&#148;), pursuant to which Merger Sub will be merged with and into the Company, with the Company as the surviving entity (the &#147;Merger&#148;), following which the Company will be
merged with and into Successor Sub (LLC), with Successor Sub (LLC) as the surviving entity, the sole member of which will be Parent (the &#147;Second Step Merger,&#148; and, together with the Merger, the &#147;Reorganization&#148;). This opinion is
furnished to you pursuant to Section&nbsp;7.12 of the Agreement. </FONT></P> <P STYLE="margin-top:12px;margin-bottom:0px"><FONT STYLE="font-family:Times New Roman" SIZE="2">For purposes of this opinion, we have examined and relied upon the
registration statement, including amendments, filed by Parent on Form S-4 (the &#147;Registration Statement&#148;) with the Securities and Exchange Commission (the &#147;Commission&#148;) pursuant to the Securities Act of 1933, as amended (the
&#147;Act&#148;); the Agreement; the letters provided to us and executed by the officers of both Parent and the Company, dated August&nbsp;27, 2013, the contents of which we assume are, and will continue to be, correct without regard to any
qualification as to knowledge intention or belief (the &#147;Tax Representation Letters&#148;); and such other documents as we have deemed necessary or appropriate; and we have assumed, with your consent, the following: </FONT></P>
<P STYLE="font-size:6px;margin-top:0px;margin-bottom:0px">&nbsp;</P>
<TABLE STYLE="BORDER-COLLAPSE:COLLAPSE" BORDER="0" CELLPADDING="0" CELLSPACING="0" WIDTH="100%">
<TR>
<TD WIDTH="4%"><FONT SIZE="1">&nbsp;</FONT></TD>
<TD WIDTH="4%" VALIGN="top" ALIGN="left"><FONT STYLE="font-family:Times New Roman" SIZE="2">1.</FONT></TD>
<TD ALIGN="left" VALIGN="top"><FONT STYLE="font-family:Times New Roman" SIZE="2">the representations contained in the Registration Statement, the Agreement, and the Tax Representation Letters and any other documents we reviewed were true, correct
and complete as of the effective times of the Merger and the Second Step Merger; </FONT></TD></TR></TABLE> <P STYLE="font-size:6px;margin-top:0px;margin-bottom:0px">&nbsp;</P>
<TABLE STYLE="BORDER-COLLAPSE:COLLAPSE" BORDER="0" CELLPADDING="0" CELLSPACING="0" WIDTH="100%">
<TR>
<TD WIDTH="4%"><FONT SIZE="1">&nbsp;</FONT></TD>
<TD WIDTH="4%" VALIGN="top" ALIGN="left"><FONT STYLE="font-family:Times New Roman" SIZE="2">2.</FONT></TD>
<TD ALIGN="left" VALIGN="top"><FONT STYLE="font-family:Times New Roman" SIZE="2">any and all obligations imposed by the Registration Statement, the Agreement and such other documents we reviewed have been or will be performed or satisfied in
accordance with their terms; and </FONT></TD></TR></TABLE> <P STYLE="font-size:6px;margin-top:0px;margin-bottom:0px">&nbsp;</P>
<TABLE STYLE="BORDER-COLLAPSE:COLLAPSE" BORDER="0" CELLPADDING="0" CELLSPACING="0" WIDTH="100%">
<TR>
<TD WIDTH="4%"><FONT SIZE="1">&nbsp;</FONT></TD>
<TD WIDTH="4%" VALIGN="top" ALIGN="left"><FONT STYLE="font-family:Times New Roman" SIZE="2">3.</FONT></TD>
<TD ALIGN="left" VALIGN="top"><FONT STYLE="font-family:Times New Roman" SIZE="2">the Merger and the Second Step Merger, each at their respective effective times, were consummated pursuant to and in accordance with the terms of the Agreement and in
the manner described in the Registration Statement. </FONT></TD></TR></TABLE> <P STYLE="margin-top:12px;margin-bottom:0px"><FONT STYLE="font-family:Times New Roman" SIZE="2">Based upon and subject to the foregoing, and our consideration of such
other matters of fact and law as we have considered necessary or appropriate, it is our opinion, under presently applicable U.S. federal income tax law, that the Reorganization will be treated for U.S. federal income tax purposes as a reorganization
within the meaning of Section&nbsp;368(a) of the Internal Revenue Code of 1986, as amended (the &#147;Code&#148;), and Parent and the Company will each be a party to that reorganization, as contemplated by Section&nbsp;368(b) of the Code.
</FONT></P>
 <p STYLE="margin-top:0px;margin-bottom:0px"><FONT SIZE="1">&nbsp;</FONT></P> <P STYLE="margin-top:0px;margin-bottom:0px" ALIGN="center"><FONT STYLE="font-family:Times New Roman" SIZE="2">1 </FONT></P>


<p Style='page-break-before:always'>
<HR  SIZE="3" style="COLOR:#999999" WIDTH="100%" ALIGN="CENTER">

 <P STYLE="margin-top:0px;margin-bottom:0px"><FONT STYLE="font-family:Times New Roman" SIZE="2">This opinion is limited to the federal income tax laws of the United States and does not purport to discuss
the consequences or effectiveness of the Reorganization under any other laws. </FONT></P> <P STYLE="margin-top:12px;margin-bottom:0px"><FONT STYLE="font-family:Times New Roman" SIZE="2">We hereby consent to the filing of this opinion as an exhibit
to the Registration Statement. In giving such consent, we do not hereby admit that we are within the category of persons whose consent is required under Section&nbsp;7 of the Act, or the rules and regulations of the Commission thereunder.
</FONT></P> <P STYLE="margin-top:12px;margin-bottom:0px"><FONT STYLE="font-family:Times New Roman" SIZE="2">Very truly yours, </FONT></P> <P STYLE="margin-top:12px;margin-bottom:0px"><FONT STYLE="font-family:Times New Roman" SIZE="2">/s/ Fox
Rothschild LLP </FONT></P>
 <p STYLE="margin-top:0px;margin-bottom:0px"><FONT SIZE="1">&nbsp;</FONT></P> <P STYLE="margin-top:0px;margin-bottom:0px" ALIGN="center"><FONT STYLE="font-family:Times New Roman" SIZE="2">2 </FONT></P>

</BODY></HTML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
