<SEC-DOCUMENT>0001144204-16-138640.txt : 20161208
<SEC-HEADER>0001144204-16-138640.hdr.sgml : 20161208
<ACCEPTANCE-DATETIME>20161208211028
ACCESSION NUMBER:		0001144204-16-138640
CONFORMED SUBMISSION TYPE:	S-3MEF
PUBLIC DOCUMENT COUNT:		3
<REFERENCE-462B>333-207969
FILED AS OF DATE:		20161208
DATE AS OF CHANGE:		20161208
EFFECTIVENESS DATE:		20161208

FILER:

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			HUDSON TECHNOLOGIES INC /NY
		CENTRAL INDEX KEY:			0000925528
		STANDARD INDUSTRIAL CLASSIFICATION:	WHOLESALE-MACHINERY, EQUIPMENT & SUPPLIES [5080]
		IRS NUMBER:				133641539
		STATE OF INCORPORATION:			NY
		FISCAL YEAR END:			1231

	FILING VALUES:
		FORM TYPE:		S-3MEF
		SEC ACT:		1933 Act
		SEC FILE NUMBER:	333-214994
		FILM NUMBER:		162042689

	BUSINESS ADDRESS:	
		STREET 1:		PO BOX 1541
		STREET 2:		ONE BLUE HILL PLAZA, 14TH FLOOR
		CITY:			PEARL RIVER
		STATE:			NY
		ZIP:			10965
		BUSINESS PHONE:		8457356000

	MAIL ADDRESS:	
		STREET 1:		PO BOX 1541
		STREET 2:		ONE BLUE HILL PLAZA, 14TH FLOOR
		CITY:			PEARL RIVER
		STATE:			NY
		ZIP:			10965

	FORMER COMPANY:	
		FORMER CONFORMED NAME:	REFRIGERANT RECLAMATION INDUSTRIES INC
		DATE OF NAME CHANGE:	19940617
</SEC-HEADER>
<DOCUMENT>
<TYPE>S-3MEF
<SEQUENCE>1
<FILENAME>v454715_s3mef.htm
<DESCRIPTION>S-3MEF
<TEXT>
<HTML>
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<P STYLE="margin: 0"></P>

<P STYLE="font: 10pt Times New Roman, Times, Serif; margin: 0pt 0; text-align: center">&nbsp;</P>

<P STYLE="font: 10pt Times New Roman, Times, Serif; margin: 0pt 0; text-align: center"><B>As filed with the Securities and Exchange
Commission on December 9, 2016</B></P>

<P STYLE="font: 10pt Times New Roman, Times, Serif; margin: 0pt 0; text-align: center">&nbsp;</P>

<P STYLE="font: 10pt Times New Roman, Times, Serif; margin: 0pt 0; text-align: right"><B>Registration No.&nbsp;333-</B></P>

<P STYLE="font: 10pt Times New Roman, Times, Serif; margin: 0pt 0">&nbsp;</P>

<P STYLE="font: 10pt Times New Roman, Times, Serif; margin: 0pt 0; text-align: center"><B>UNITED STATES</B></P>

<P STYLE="font: 10pt Times New Roman, Times, Serif; margin: 0pt 0; text-align: center"><B>SECURITIES AND EXCHANGE COMMISSION</B></P>

<P STYLE="font: 10pt Times New Roman, Times, Serif; margin: 0pt 0; text-align: center"><B>Washington, DC 20549</B></P>

<P STYLE="font: 10pt Times New Roman, Times, Serif; margin: 0pt 0; text-align: center"><B>&nbsp;</B></P>

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<P STYLE="font: 10pt Times New Roman, Times, Serif; margin: 0pt 0; text-align: center"><B>&nbsp;</B></P>

<P STYLE="font: 10pt Times New Roman, Times, Serif; margin: 0pt 0; text-align: center"><B>FORM S-3</B></P>

<P STYLE="font: 10pt Times New Roman, Times, Serif; margin: 0pt 0; text-align: center"><B>REGISTRATION STATEMENT</B></P>

<P STYLE="font: 10pt Times New Roman, Times, Serif; margin: 0pt 0; text-align: center"><B>UNDER</B></P>

<P STYLE="font: 10pt Times New Roman, Times, Serif; margin: 0pt 0; text-align: center"><B>THE SECURITIES ACT OF 1933</B></P>

<P STYLE="font: 10pt Times New Roman, Times, Serif; margin: 0pt 0; text-align: center">&nbsp;</P>

<!-- Field: Rule-Page --><DIV ALIGN="LEFT" STYLE="margin-top: 1pt; margin-bottom: 1pt"><DIV STYLE="font-size: 1pt; border-top: Black 0.5pt solid; width: 100%">&nbsp;</DIV></DIV><!-- Field: /Rule-Page -->

<P STYLE="font: 10pt Times New Roman, Times, Serif; margin: 0pt 0">&nbsp;</P>

<P STYLE="font: 10pt Times New Roman, Times, Serif; margin: 0pt 0; text-align: center"><B>HUDSON TECHNOLOGIES, INC.</B></P>

<P STYLE="font: 10pt Times New Roman, Times, Serif; margin: 0pt 0; text-align: center">(Exact name of registrant as specified in
its charter)</P>

<P STYLE="font: 10pt Times New Roman, Times, Serif; margin: 0pt 0">&nbsp;</P>

<TABLE CELLSPACING="0" CELLPADDING="0" STYLE="font: 10pt Times New Roman, Times, Serif; width: 100%; border-collapse: collapse">
<TR>
    <TD STYLE="vertical-align: top; width: 33%; text-align: center"><B>New York</B></TD>
    <TD STYLE="vertical-align: top; width: 34%">&nbsp;</TD>
    <TD STYLE="vertical-align: top; width: 33%; text-align: center"><B>13-3641539</B></TD></TR>
<TR>
    <TD STYLE="vertical-align: top">
        <P STYLE="font: 10pt Times New Roman, Times, Serif; margin: 0pt 0; text-align: center">(State or other jurisdiction</P>
        <P STYLE="font: 10pt Times New Roman, Times, Serif; margin: 0pt 0; text-align: center">of incorporation or organization)</P></TD>
    <TD STYLE="vertical-align: top">&nbsp;</TD>
    <TD STYLE="vertical-align: top">
        <P STYLE="font: 10pt Times New Roman, Times, Serif; margin: 0pt 0; text-align: center">(I.R.S. employer</P>
        <P STYLE="font: 10pt Times New Roman, Times, Serif; margin: 0pt 0; text-align: center">identification no.)</P></TD></TR>
</TABLE>
<P STYLE="font: 10pt Times New Roman, Times, Serif; margin: 0pt 0">&nbsp;</P>

<P STYLE="font: 10pt Times New Roman, Times, Serif; margin: 0pt 0; text-align: center"><B>P.O. Box 1541</B></P>

<P STYLE="font: 10pt Times New Roman, Times, Serif; margin: 0pt 0; text-align: center"><B>One Blue Hill Plaza</B></P>

<P STYLE="font: 10pt Times New Roman, Times, Serif; margin: 0pt 0; text-align: center"><B>Pearl River, NY 10965</B></P>

<P STYLE="font: 10pt Times New Roman, Times, Serif; margin: 0pt 0; text-align: center"><B>Telephone: (845)&nbsp;735-6000</B></P>

<P STYLE="font: 10pt Times New Roman, Times, Serif; margin: 0pt 0; text-align: center">(Address, including zip code, and telephone
number, including area code, of registrant&rsquo;s principal executive offices)</P>

<P STYLE="font: 10pt Times New Roman, Times, Serif; margin: 0pt 0; text-align: center">&nbsp;</P>

<P STYLE="font: 10pt Times New Roman, Times, Serif; margin: 0pt 0; text-align: center"><B>Kevin J. Zugibe, Chairman and Chief Executive
Officer</B></P>

<P STYLE="font: 10pt Times New Roman, Times, Serif; margin: 0pt 0; text-align: center"><B>Hudson Technologies, Inc.</B></P>

<P STYLE="font: 10pt Times New Roman, Times, Serif; margin: 0pt 0; text-align: center"><B>P.O. Box 1541</B></P>

<P STYLE="font: 10pt Times New Roman, Times, Serif; margin: 0pt 0; text-align: center"><B>One Blue Hill Plaza</B></P>

<P STYLE="font: 10pt Times New Roman, Times, Serif; margin: 0pt 0; text-align: center"><B>Pearl River, NY 10965</B></P>

<P STYLE="font: 10pt Times New Roman, Times, Serif; margin: 0pt 0; text-align: center"><B>Telephone: (845)&nbsp;735-6000</B></P>

<P STYLE="font: 10pt Times New Roman, Times, Serif; margin: 0pt 0; text-align: center">(Name, address, including zip code, and
telephone number, including area code, of agent for service)</P>

<P STYLE="font: 10pt Times New Roman, Times, Serif; margin: 0pt 0; text-align: center">&nbsp;</P>

<!-- Field: Rule-Page --><DIV ALIGN="LEFT" STYLE="margin-top: 1pt; margin-bottom: 1pt"><DIV STYLE="font-size: 1pt; border-top: Black 0.5pt solid; width: 100%">&nbsp;</DIV></DIV><!-- Field: /Rule-Page -->

<P STYLE="font: 10pt Times New Roman, Times, Serif; margin: 0pt 0; text-align: center"><B><I>Copies to:</I></B></P>

<P STYLE="font: 10pt Times New Roman, Times, Serif; margin: 0pt 0">&nbsp;</P>

<P STYLE="font: 10pt Times New Roman, Times, Serif; margin: 0pt 0; text-align: center"><B>Michael Grundei, Esq.</B></P>

<P STYLE="font: 10pt Times New Roman, Times, Serif; margin: 0pt 0; text-align: center"><B>Wiggin and Dana LLP</B></P>

<P STYLE="font: 10pt Times New Roman, Times, Serif; margin: 0pt 0; text-align: center"><B>Two Stamford Plaza</B></P>

<P STYLE="font: 10pt Times New Roman, Times, Serif; margin: 0pt 0; text-align: center"><B>281 Tresser Boulevard</B></P>

<P STYLE="font: 10pt Times New Roman, Times, Serif; margin: 0pt 0; text-align: center"><B>Stamford, CT 06901</B></P>

<P STYLE="font: 10pt Times New Roman, Times, Serif; margin: 0pt 0; text-align: center"><B>Telephone: (203) 363-7600</B></P>

<P STYLE="font: 10pt Times New Roman, Times, Serif; margin: 0pt 0; text-align: center"><B>Facsimile: (203) 363-7676</B></P>

<P STYLE="font: 10pt Times New Roman, Times, Serif; margin: 0pt 0; text-align: center"><B>&nbsp;</B></P>

<!-- Field: Rule-Page --><DIV ALIGN="LEFT" STYLE="margin-top: 1pt; margin-bottom: 1pt"><DIV STYLE="font-size: 1pt; border-top: Black 0.5pt solid; width: 100%">&nbsp;</DIV></DIV><!-- Field: /Rule-Page -->

<P STYLE="font: 10pt Times New Roman, Times, Serif; margin: 0pt 0; text-indent: 31.7pt">&nbsp;</P>

<P STYLE="font: 10pt Times New Roman, Times, Serif; margin: 0pt 0; text-indent: 31.7pt"><B>APPROXIMATE DATE OF COMMENCEMENT OF
PROPOSED SALE TO THE PUBLIC:</B>&nbsp;From time to time after this Registration Statement becomes effective.</P>

<P STYLE="font: 10pt Times New Roman, Times, Serif; margin: 0pt 0; text-indent: 0.5in">&nbsp;</P>

<P STYLE="font: 10pt Times New Roman, Times, Serif; margin: 0pt 0; text-indent: 0.5in">If the only securities being registered
on this Form are being offered pursuant to dividend or interest reinvestment plans, please check the following box: <FONT STYLE="font-family: Wingdings">&uml;</FONT></P>

<P STYLE="font: 10pt Times New Roman, Times, Serif; margin: 0pt 0; text-indent: 0.5in">&nbsp;</P>

<P STYLE="font: 10pt Times New Roman, Times, Serif; margin: 0pt 0; text-indent: 0.5in">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: <FONT STYLE="font-family: Wingdings">x</FONT></P>

<P STYLE="font: 10pt Times New Roman, Times, Serif; margin: 0pt 0; text-indent: 0.5in">&nbsp;</P>

<P STYLE="font: 10pt Times New Roman, Times, Serif; margin: 0pt 0; text-indent: 0.5in">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. <FONT STYLE="font-family: Wingdings">x
</FONT>333-207969</P>

<P STYLE="font: 10pt Times New Roman, Times, Serif; margin: 0pt 0; text-indent: 0.5in">&nbsp;</P>

<P STYLE="font: 10pt Times New Roman, Times, Serif; margin: 0pt 0; text-indent: 0.5in">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. <FONT STYLE="font-family: Wingdings">&uml;</FONT></P>

<P STYLE="font: 10pt Times New Roman, Times, Serif; margin: 0pt 0; text-indent: 0.5in">&nbsp;</P>

<P STYLE="font: 10pt Times New Roman, Times, Serif; margin: 0pt 0; text-indent: 0.5in">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. <FONT STYLE="font-family: Wingdings">&uml;</FONT></P>

<P STYLE="font: 10pt Times New Roman, Times, Serif; margin: 0pt 0; text-indent: 0.5in">&nbsp;</P>

<P STYLE="font: 10pt Times New Roman, Times, Serif; margin: 0pt 0; text-indent: 0.5in">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. <FONT STYLE="font-family: Wingdings">&uml;</FONT></P>

<P STYLE="font: 10pt Times New Roman, Times, Serif; margin: 0pt 0; text-indent: 0.5in">&nbsp;</P>

<P STYLE="font: 10pt Times New Roman, Times, Serif; margin: 0pt 0; text-indent: 0.5in">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 &ldquo;large accelerated filer&rdquo;, &ldquo;accelerated filer&rdquo; and &ldquo;smaller reporting company&rdquo; in Rule 12b-2
of the Exchange Act. (Check one):</P>

<P STYLE="font: 10pt Times New Roman, Times, Serif; margin: 0pt 0; text-indent: 0.5in">&nbsp;</P>

<TABLE CELLSPACING="0" CELLPADDING="0" STYLE="font: 10pt Times New Roman, Times, Serif; width: 100%; border-collapse: collapse">
<TR STYLE="background-color: white">
    <TD STYLE="width: 20%"><FONT STYLE="font-size: 10pt">Large accelerated filer</FONT>&nbsp;</TD>
    <TD STYLE="width: 3%"><FONT STYLE="font-family: Wingdings; font-size: 10pt">&uml;</FONT></TD>
    <TD STYLE="width: 5%">&nbsp;</TD>
    <TD STYLE="width: 42%">&nbsp;</TD>
    <TD STYLE="width: 5%">&nbsp;</TD>
    <TD STYLE="width: 25%"><FONT STYLE="font-size: 10pt">Accelerated filer</FONT> <FONT STYLE="font-family: Wingdings">x</FONT></TD></TR>
<TR STYLE="background-color: white">
    <TD><FONT STYLE="font-size: 10pt">Non-accelerated filer</FONT>&nbsp;</TD>
    <TD><FONT STYLE="font-family: Wingdings; font-size: 10pt">&uml;</FONT></TD>
    <TD COLSPAN="2"><FONT STYLE="font-size: 10pt">(Do not check if a smaller reporting company)</FONT>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD><FONT STYLE="font-size: 10pt">Smaller reporting company</FONT> <FONT STYLE="font-family: Wingdings">&uml;</FONT></TD></TR>
</TABLE>
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<P STYLE="font: 10pt Times New Roman, Times, Serif; margin: 0pt 0">&nbsp;</P>


<!-- Field: Page; Sequence: 1 -->
    <DIV STYLE="margin-top: 12pt; margin-bottom: 6pt; border-bottom: Black 1pt solid"><P STYLE="margin: 0pt">&nbsp;</P></DIV>
    <DIV STYLE="page-break-before: always; margin-top: 6pt; margin-bottom: 12pt"><P STYLE="margin: 0pt">&nbsp;</P></DIV>
    <!-- Field: /Page -->

<P STYLE="font: 10pt Times New Roman, Times, Serif; margin: 0pt 0; text-align: center">&nbsp;</P>

<P STYLE="font: 10pt Times New Roman, Times, Serif; margin: 0pt 0; text-align: center"><B>CALCULATION OF REGISTRATION FEE</B></P>

<P STYLE="font: 10pt Times New Roman, Times, Serif; margin: 0pt 0">&nbsp;</P>

<TABLE CELLPADDING="0" CELLSPACING="0" STYLE="border-collapse: collapse; width: 100%; font: 10pt Times New Roman, Times, Serif">
<TR STYLE="vertical-align: bottom">
    <TD STYLE="font-size: 10pt; font-weight: bold; text-align: center; border-bottom: Black 1pt solid">Title&nbsp;of Each Class&nbsp;of&nbsp;Securities&nbsp;to&nbsp;be&nbsp;Registered (1)</TD><TD STYLE="font: 10pt Times New Roman, Times, Serif; padding-bottom: 1pt">&nbsp;</TD>
    <TD COLSPAN="2" STYLE="font: 10pt Times New Roman, Times, Serif; text-align: center; border-bottom: Black 1pt solid"><P STYLE="font: 10pt Times New Roman, Times, Serif; margin: 0pt 0; text-align: center"><B>Amount to be</B></P> <P STYLE="font: 10pt Times New Roman, Times, Serif; margin: 0pt 0; text-align: center"><B>Registered(2)</B></P></TD><TD STYLE="padding-bottom: 1pt; font: 10pt Times New Roman, Times, Serif">&nbsp;</TD><TD STYLE="font: 10pt Times New Roman, Times, Serif; padding-bottom: 1pt">&nbsp;</TD>
    <TD COLSPAN="2" STYLE="font: 10pt Times New Roman, Times, Serif; text-align: center; border-bottom: Black 1pt solid"><P STYLE="font: 10pt Times New Roman, Times, Serif; margin: 0pt 0; text-align: center"><B>Proposed&nbsp;Maximum</B></P> <P STYLE="font: 10pt Times New Roman, Times, Serif; margin: 0pt 0; text-align: center"><B>Offering Price Per</B></P> <P STYLE="font: 10pt Times New Roman, Times, Serif; margin: 0pt 0; text-align: center"><B>Security</B></P></TD><TD STYLE="padding-bottom: 1pt; font: 10pt Times New Roman, Times, Serif">&nbsp;</TD><TD STYLE="font: 10pt Times New Roman, Times, Serif; padding-bottom: 1pt">&nbsp;</TD>
    <TD COLSPAN="2" STYLE="font: 10pt Times New Roman, Times, Serif; text-align: center; border-bottom: Black 1pt solid"><P STYLE="font: 10pt Times New Roman, Times, Serif; margin: 0pt 0; text-align: center">&nbsp;<B>Proposed&nbsp;Maximum</B></P> <P STYLE="font: 10pt Times New Roman, Times, Serif; margin: 0pt 0; text-align: center"><B>Aggregate</B></P> <P STYLE="font: 10pt Times New Roman, Times, Serif; margin: 0pt 0; text-align: center"><B>Offering&nbsp;Price</B></P></TD><TD STYLE="padding-bottom: 1pt; font: 10pt Times New Roman, Times, Serif">&nbsp;</TD><TD STYLE="font: 10pt Times New Roman, Times, Serif; padding-bottom: 1pt">&nbsp;</TD>
    <TD COLSPAN="2" STYLE="font: 10pt Times New Roman, Times, Serif; text-align: center; border-bottom: Black 1pt solid"><P STYLE="font: 10pt Times New Roman, Times, Serif; margin: 0pt 0; text-align: center"><B>Amount&nbsp;of</B></P> <P STYLE="font: 10pt Times New Roman, Times, Serif; margin: 0pt 0; text-align: center"><B>Registration&nbsp;<BR> Fee</B></P></TD><TD STYLE="padding-bottom: 1pt; font: 10pt Times New Roman, Times, Serif">&nbsp;</TD></TR>
<TR STYLE="vertical-align: bottom">
    <TD STYLE="font-size: 10pt">&nbsp;</TD><TD STYLE="font-size: 10pt">&nbsp;</TD>
    <TD COLSPAN="2" STYLE="font-size: 10pt; text-align: right">&nbsp;</TD><TD STYLE="font-size: 10pt">&nbsp;</TD><TD STYLE="font-size: 10pt">&nbsp;</TD>
    <TD COLSPAN="2" STYLE="font-size: 10pt; text-align: right">&nbsp;</TD><TD STYLE="font-size: 10pt">&nbsp;</TD><TD STYLE="font-size: 10pt">&nbsp;</TD>
    <TD COLSPAN="2" STYLE="font-size: 10pt; text-align: right">&nbsp;</TD><TD STYLE="font-size: 10pt">&nbsp;</TD><TD STYLE="font-size: 10pt">&nbsp;</TD>
    <TD COLSPAN="2" STYLE="font-size: 10pt; text-align: right">&nbsp;</TD><TD STYLE="font-size: 10pt">&nbsp;</TD></TR>
<TR STYLE="vertical-align: bottom; background-color: rgb(204,238,255)">
    <TD STYLE="width: 44%; font-size: 10pt">Common Stock, par value $.01 per share</TD><TD STYLE="width: 2%; font-size: 10pt">&nbsp;</TD>
    <TD STYLE="width: 1%; font-size: 10pt; text-align: left">&nbsp;</TD><TD STYLE="width: 10%; font-size: 10pt; text-align: right">&mdash;</TD><TD STYLE="width: 1%; font-size: 10pt; text-align: left">&nbsp;</TD><TD STYLE="width: 2%; font-size: 10pt">&nbsp;</TD>
    <TD STYLE="width: 1%; font-size: 10pt; text-align: left">&nbsp;</TD><TD STYLE="width: 10%; font-size: 10pt; text-align: right">&mdash;</TD><TD STYLE="width: 1%; font-size: 10pt; text-align: left">&nbsp;</TD><TD STYLE="width: 2%; font-size: 10pt">&nbsp;</TD>
    <TD STYLE="width: 1%; font-size: 10pt; text-align: left">&nbsp;</TD><TD STYLE="width: 10%; font-size: 10pt; text-align: right">&mdash;</TD><TD STYLE="width: 1%; font-size: 10pt; text-align: left">&nbsp;</TD><TD STYLE="width: 2%; font-size: 10pt">&nbsp;</TD>
    <TD STYLE="width: 1%; font-size: 10pt; text-align: left">&nbsp;</TD><TD STYLE="width: 10%; font-size: 10pt; text-align: right">&mdash;</TD><TD STYLE="width: 1%; font-size: 10pt; text-align: left">&nbsp;</TD></TR>
<TR STYLE="vertical-align: bottom; background-color: White">
    <TD STYLE="font-size: 10pt">Preferred Stock, par value $.01 per share</TD><TD STYLE="font-size: 10pt">&nbsp;</TD>
    <TD STYLE="font-size: 10pt; text-align: left">&nbsp;</TD><TD STYLE="font-size: 10pt; text-align: right">&mdash;</TD><TD STYLE="font-size: 10pt; text-align: left">&nbsp;</TD><TD STYLE="font-size: 10pt">&nbsp;</TD>
    <TD STYLE="font-size: 10pt; text-align: left">&nbsp;</TD><TD STYLE="font-size: 10pt; text-align: right">&mdash;</TD><TD STYLE="font-size: 10pt; text-align: left">&nbsp;</TD><TD STYLE="font-size: 10pt">&nbsp;</TD>
    <TD STYLE="font-size: 10pt; text-align: left">&nbsp;</TD><TD STYLE="font-size: 10pt; text-align: right">&mdash;</TD><TD STYLE="font-size: 10pt; text-align: left">&nbsp;</TD><TD STYLE="font-size: 10pt">&nbsp;</TD>
    <TD STYLE="font-size: 10pt; text-align: left">&nbsp;</TD><TD STYLE="font-size: 10pt; text-align: right">&mdash;</TD><TD STYLE="font-size: 10pt; text-align: left">&nbsp;</TD></TR>
<TR STYLE="vertical-align: bottom; background-color: rgb(204,238,255)">
    <TD STYLE="font-size: 10pt">Warrants</TD><TD STYLE="font-size: 10pt">&nbsp;</TD>
    <TD STYLE="font-size: 10pt; text-align: left">&nbsp;</TD><TD STYLE="font-size: 10pt; text-align: right">&mdash;</TD><TD STYLE="font-size: 10pt; text-align: left">&nbsp;</TD><TD STYLE="font-size: 10pt">&nbsp;</TD>
    <TD STYLE="font-size: 10pt; text-align: left">&nbsp;</TD><TD STYLE="font-size: 10pt; text-align: right">&mdash;</TD><TD STYLE="font-size: 10pt; text-align: left">&nbsp;</TD><TD STYLE="font-size: 10pt">&nbsp;</TD>
    <TD STYLE="font-size: 10pt; text-align: left">&nbsp;</TD><TD STYLE="font-size: 10pt; text-align: right">&mdash;</TD><TD STYLE="font-size: 10pt; text-align: left">&nbsp;</TD><TD STYLE="font-size: 10pt">&nbsp;</TD>
    <TD STYLE="font-size: 10pt; text-align: left">&nbsp;</TD><TD STYLE="font-size: 10pt; text-align: right">&mdash;</TD><TD STYLE="font-size: 10pt; text-align: left">&nbsp;</TD></TR>
<TR STYLE="vertical-align: bottom; background-color: White">
    <TD STYLE="font-size: 10pt; text-align: left">Debt Securities</TD><TD STYLE="font-size: 10pt">&nbsp;</TD>
    <TD STYLE="font-size: 10pt; text-align: left">&nbsp;</TD><TD STYLE="font-size: 10pt; text-align: right">&mdash;</TD><TD STYLE="font-size: 10pt; text-align: left">&nbsp;</TD><TD STYLE="font-size: 10pt">&nbsp;</TD>
    <TD STYLE="font-size: 10pt; text-align: left">&nbsp;</TD><TD STYLE="font-size: 10pt; text-align: right">&mdash;</TD><TD STYLE="font-size: 10pt; text-align: left">&nbsp;</TD><TD STYLE="font-size: 10pt">&nbsp;</TD>
    <TD STYLE="font-size: 10pt; text-align: left">&nbsp;</TD><TD STYLE="font-size: 10pt; text-align: right">&mdash;</TD><TD STYLE="font-size: 10pt; text-align: left">&nbsp;</TD><TD STYLE="font-size: 10pt">&nbsp;</TD>
    <TD STYLE="font-size: 10pt; text-align: left">&nbsp;</TD><TD STYLE="font-size: 10pt; text-align: right">&mdash;</TD><TD STYLE="font-size: 10pt; text-align: left">&nbsp;</TD></TR>
<TR STYLE="vertical-align: bottom; background-color: rgb(204,238,255)">
    <TD STYLE="font-size: 10pt; padding-bottom: 1pt">Units(3)</TD><TD STYLE="font-size: 10pt; padding-bottom: 1pt">&nbsp;</TD>
    <TD STYLE="font-size: 10pt; text-align: left">&nbsp;</TD><TD STYLE="font-size: 10pt; text-align: right">&mdash;</TD><TD STYLE="padding-bottom: 1pt; font-size: 10pt; text-align: left">&nbsp;</TD><TD STYLE="font-size: 10pt; padding-bottom: 1pt">&nbsp;</TD>
    <TD STYLE="font-size: 10pt; text-align: left">&nbsp;</TD><TD STYLE="font-size: 10pt; text-align: right">&mdash;</TD><TD STYLE="padding-bottom: 1pt; font-size: 10pt; text-align: left">&nbsp;</TD><TD STYLE="font-size: 10pt; padding-bottom: 1pt">&nbsp;</TD>
    <TD STYLE="border-bottom: Black 1pt solid; font-size: 10pt; text-align: left">&nbsp;</TD><TD STYLE="border-bottom: Black 1pt solid; font-size: 10pt; text-align: right">&mdash;</TD><TD STYLE="padding-bottom: 1pt; font-size: 10pt; text-align: left">&nbsp;</TD><TD STYLE="font-size: 10pt; padding-bottom: 1pt">&nbsp;</TD>
    <TD STYLE="border-bottom: Black 1pt solid; font-size: 10pt; text-align: left">&nbsp;</TD><TD STYLE="border-bottom: Black 1pt solid; font-size: 10pt; text-align: right">&mdash;</TD><TD STYLE="padding-bottom: 1pt; font-size: 10pt; text-align: left">&nbsp;</TD></TR>
<TR STYLE="vertical-align: bottom; background-color: White">
    <TD STYLE="font-size: 10pt; font-weight: bold; padding-bottom: 1pt">Total:</TD><TD STYLE="font-size: 10pt; padding-bottom: 1pt">&nbsp;</TD>
    <TD STYLE="font-size: 10pt; text-align: left">$</TD><TD STYLE="font-size: 10pt; text-align: right">1,750,000.00</TD><TD STYLE="padding-bottom: 1pt; font-size: 10pt; text-align: left">&nbsp;</TD><TD STYLE="font-size: 10pt; padding-bottom: 1pt">&nbsp;</TD>
    <TD STYLE="font-size: 10pt; text-align: left">&nbsp;</TD><TD STYLE="font-size: 10pt; text-align: right">(4</TD><TD STYLE="font-size: 10pt; text-align: left">)</TD><TD STYLE="font-size: 10pt; padding-bottom: 1pt">&nbsp;</TD>
    <TD STYLE="border-bottom: Black 1pt solid; font-size: 10pt; text-align: left">$</TD><TD STYLE="border-bottom: Black 1pt solid; font-size: 10pt; text-align: right">1,750,000.00</TD><TD STYLE="padding-bottom: 1pt; font-size: 10pt; text-align: left">&nbsp;</TD><TD STYLE="font-size: 10pt; padding-bottom: 1pt">&nbsp;</TD>
    <TD STYLE="border-bottom: Black 1pt solid; font-size: 10pt; text-align: left">&nbsp;</TD><TD STYLE="border-bottom: Black 1pt solid; font-size: 10pt; text-align: right">$&nbsp;&nbsp;&nbsp;202.83</TD><TD NOWRAP STYLE="padding-bottom: 1pt; font-size: 10pt; text-align: left"> (5)(6)</TD></TR>
</TABLE>


<P STYLE="margin: 0">&nbsp;</P>

<TABLE CELLSPACING="0" CELLPADDING="0" STYLE="font: 10pt Times New Roman, Times, Serif; width: 100%; border-collapse: collapse">
<TR>
    <TD STYLE="vertical-align: top; border-top: black 2.25pt double; width: 5%">&nbsp;</TD>
    <TD STYLE="vertical-align: top; border-top: black 2.25pt double; width: 80%">&nbsp;</TD>
    <TD STYLE="width: 15%">&nbsp;</TD></TR>
<TR>
    <TD STYLE="vertical-align: top"><FONT STYLE="font-family: Times New Roman, Times, Serif; font-size: 10pt">(1)</FONT></TD>
    <TD STYLE="vertical-align: top">
        <P STYLE="font: 10pt Times New Roman, Times, Serif; margin: 0pt 0">The Registrant previously registered securities, including common
        stock, preferred stock, warrants, debt securities and units comprised of same, with an aggregate offering price of $50,000,000
        on a Registration Statement on Form S-3 (File No. 333-207969) filed by the Company on November 12, 2015, as amended on December
        18, 2015, and declared effective by the Securities and Exchange Commission on December 18, 2015 (the &ldquo;Registration Statement&rdquo;).
        In accordance with Rule 462(b) under the Securities Act, an additional amount of securities, including common stock, preferred
        stock, warrants, debt securities and units comprised of same having a proposed maximum aggregate offering price of $1,750,000 is
        hereby registered, representing no more than 20% of the maximum aggregate offering price of securities available for issuance under
        the Registration Statement. In no event will the maximum aggregate offering price of all securities issued pursuant to this Registration
        Statement exceed that registered under such registration statements. The securities registered also include such indeterminate
        number of shares of common stock and preferred stock and amount of debt securities as may be issued upon conversion of or exchange
        for preferred stock or debt securities that provide for conversion or exchange, upon exercise of warrants or pursuant to the anti-dilution
        provisions of any such securities.</P>
        <P STYLE="font: 10pt Times New Roman, Times, Serif; margin: 0pt 0">&nbsp;</P></TD>
    <TD>&nbsp;</TD></TR>
<TR>
    <TD STYLE="vertical-align: top; padding-bottom: 12pt"><FONT STYLE="font-family: Times New Roman, Times, Serif; font-size: 10pt">(2) </FONT></TD>
    <TD STYLE="vertical-align: top; padding-bottom: 12pt"><FONT STYLE="font-family: Times New Roman, Times, Serif; font-size: 10pt">Pursuant to Rule 416 under the Securities Act of 1933, as amended, or Securities Act, the securities being registered hereunder also include such indeterminate number of shares of common stock and preferred stock as may be issuable with respect to the shares being registered hereunder as a result of stock splits, stock dividends or similar transactions. </FONT></TD>
    <TD STYLE="padding-bottom: 12pt">&nbsp;</TD></TR>
<TR>
    <TD STYLE="vertical-align: top; padding-bottom: 12pt"><FONT STYLE="font-family: Times New Roman, Times, Serif; font-size: 10pt">(3)</FONT></TD>
    <TD STYLE="vertical-align: top; padding-bottom: 12pt"><FONT STYLE="font-family: Times New Roman, Times, Serif; font-size: 10pt">Consisting of some or all of the securities listed above, in any combination, including common stock, preferred stock, warrants and debt securities.</FONT></TD>
    <TD STYLE="padding-bottom: 12pt">&nbsp;</TD></TR>
<TR>
    <TD STYLE="vertical-align: top; padding-bottom: 12pt"><FONT STYLE="font-family: Times New Roman, Times, Serif; font-size: 10pt">(4)</FONT></TD>
    <TD STYLE="vertical-align: top; padding-bottom: 12pt"><FONT STYLE="font-family: Times New Roman, Times, Serif; font-size: 10pt">The proposed maximum aggregate offering price per class of security in primary offerings will be determined from time to time by the registrant in connection with the issuance by the registrant of the securities registered hereunder and is not specified as to each class of security pursuant to General Instruction II.D of Form S-3 under the Securities Act.</FONT></TD>
    <TD STYLE="padding-bottom: 12pt">&nbsp;</TD></TR>
<TR>
    <TD STYLE="vertical-align: top; padding-bottom: 12pt"><FONT STYLE="font-family: Times New Roman, Times, Serif; font-size: 10pt">(5)</FONT></TD>
    <TD STYLE="vertical-align: top; padding-bottom: 12pt"><FONT STYLE="font-family: Times New Roman, Times, Serif; font-size: 10pt">The amount of the registration fee has been calculated in accordance with Rule 457(o) under the Securities Act.</FONT></TD>
    <TD STYLE="padding-bottom: 12pt">&nbsp;</TD></TR>
<TR>
    <TD STYLE="vertical-align: top"><FONT STYLE="font-family: Times New Roman, Times, Serif; font-size: 10pt">(6)</FONT></TD>
    <TD STYLE="vertical-align: top"><FONT STYLE="font-family: Times New Roman, Times, Serif; font-size: 10pt">Determined in accordance with Section&nbsp;6(b) of the Securities Act at a rate equal to $115.90 per $1,000,000 of the proposed maximum aggregate offering price.</FONT></TD>
    <TD>&nbsp;</TD></TR>
</TABLE>
<P STYLE="font: 10pt Times New Roman, Times, Serif; margin: 0pt 0">&nbsp;</P>

<P STYLE="font: 10pt Times New Roman, Times, Serif; margin: 0pt 0">&nbsp;</P>

<P STYLE="font: 10pt Times New Roman, Times, Serif; margin: 0pt 0"></P>


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<P STYLE="font: 10pt Times New Roman, Times, Serif; margin: 0pt 0; text-align: center">&nbsp;</P>

<P STYLE="font: 10pt Times New Roman, Times, Serif; margin-top: 0pt; margin-bottom: 0pt; text-align: center"><B>EXPLANATORY NOTE AND INCORPORATION BY
REFERENCE</B></P>

<P STYLE="font: 10pt Times New Roman, Times, Serif; margin: 0pt 0; text-align: center"><B>&nbsp;</B></P>

<P STYLE="font: 10pt Times New Roman, Times, Serif; margin: 0pt 0; text-align: justify; text-indent: 0.5in">This registration statement
is being filed to register an additional $1,750,000 of securities, including common stock, preferred stock, debt securities, warrants
and units comprised of same, of Hudson Technologies, Inc., a New York corporation, pursuant to Rule 462(b) under the Securities
Act of 1933, as amended and General Instruction IV of Form S-3. This registration statement incorporates by reference the contents
of the registrant&rsquo;s registration statement on Form S-3 (File No. 333-207969), as amended, which was declared effective by
the Commission on December 18, 2015, including all amendments and exhibits thereto and all information incorporated by reference
therein, other than the exhibits filed herewith. The Company is filing this Registration Statement for the sole purpose of increasing
the maximum aggregate offering amount of securities registered under the Prior Registration Statement by $1,750,000.</P>

<P STYLE="font: 10pt Times New Roman, Times, Serif; margin: 0pt 0; text-align: justify">&nbsp;</P>

<P STYLE="font: 10pt Times New Roman, Times, Serif; margin: 0pt 0; text-indent: 0.5in">The required opinion and consent is listed
on an Exhibit Index attached hereto and filed herewith.</P>

<P STYLE="font: 10pt Times New Roman, Times, Serif; margin: 0pt 0">&nbsp;</P>

<P STYLE="font: 10pt Times New Roman, Times, Serif; margin: 0pt 0; text-indent: 0.5in">The registrant hereby certifies to the Commission
that (i) it has instructed its bank to pay the Commission the filing fee set forth in the cover page of this registration statement
by wire transfer of such amount to the Commission&rsquo;s account as soon as practicable (but no later than the close of business
on December 9, 2016); (ii) it will not revoke such instruction; and (iii) it has sufficient funds in the relevant account to cover
the amount of such filing fee.</P>

<P STYLE="font: 10pt Times New Roman, Times, Serif; margin: 0pt 0">&nbsp;&nbsp;</P>


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<P STYLE="font: 10pt Times New Roman, Times, Serif; margin: 0pt 0">&nbsp;&nbsp;</P>

<P STYLE="font: bold 10pt Times New Roman, Times, Serif; margin: 0pt 0; text-align: center">SIGNATURES</P>

<P STYLE="font: bold 10pt Times New Roman, Times, Serif; margin: 0pt 0; text-align: center">&nbsp;</P>

<P STYLE="font: 10pt Times New Roman, Times, Serif; margin: 0pt 0; text-indent: 0.5in">Pursuant to the requirements of the Securities
Act of 1933, the Registrant 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 registration statement to be signed on its behalf by the undersigned, thereunto duly authorized,
in the City of Pearl River, State of New York, on the 8th day of December, 2016.</P>

<P STYLE="font: 10pt Times New Roman, Times, Serif; margin: 0pt 0; text-indent: 0.5in">&nbsp;</P>

<P STYLE="font: 10pt Times New Roman, Times, Serif; margin: 0pt 0; text-align: justify"></P>

<TABLE CELLSPACING="0" CELLPADDING="0" STYLE="font: 10pt Times New Roman, Times, Serif; width: 100%; border-collapse: collapse">
<TR STYLE="vertical-align: top; background-color: white">
    <TD STYLE="font-size: 10pt">&nbsp;</TD>
    <TD COLSPAN="2" STYLE="text-align: justify; font-size: 10pt"><FONT STYLE="font-family: Times New Roman, Times, Serif; font-size: 10pt"><B>HUDSON TECHNOLOGIES, INC.</B></FONT></TD></TR>
<TR STYLE="vertical-align: top; background-color: white">
    <TD STYLE="width: 50%">
        <P STYLE="font: 10pt Times New Roman, Times, Serif; margin: 0pt 0">&nbsp;</P>
        <P STYLE="font: 10pt Times New Roman, Times, Serif; margin: 0pt 0">&nbsp;</P></TD>
    <TD STYLE="width: 5%">
        <P STYLE="font: 10pt Times New Roman, Times, Serif; margin: 0pt 0"></P></TD>
    <TD STYLE="width: 45%">
        <P STYLE="font: 10pt Times New Roman, Times, Serif; margin: 0pt 0"></P></TD></TR>
<TR STYLE="vertical-align: top; background-color: white">
    <TD STYLE="font-size: 10pt">&nbsp;</TD>
    <TD STYLE="font-size: 10pt"><FONT STYLE="font-family: Times New Roman, Times, Serif; font-size: 10pt">By:&nbsp;</FONT></TD>
    <TD STYLE="border-bottom: black 1pt solid; font-size: 10pt"><FONT STYLE="font-family: Times New Roman, Times, Serif; font-size: 10pt">/s/ KEVIN J. ZUGIBE</FONT></TD></TR>
<TR STYLE="vertical-align: top; background-color: white">
    <TD COLSPAN="2" STYLE="text-align: center; font-size: 10pt">&nbsp;</TD>
    <TD STYLE="font-size: 10pt"><FONT STYLE="font-family: Times New Roman, Times, Serif; font-size: 10pt">Kevin J. Zugibe,</FONT></TD></TR>
<TR STYLE="vertical-align: top; background-color: white">
    <TD COLSPAN="2" STYLE="font-size: 10pt">&nbsp;</TD>
    <TD STYLE="text-align: justify; font-size: 10pt"><FONT STYLE="font-family: Times New Roman, Times, Serif; font-size: 10pt">Chairman and Chief Executive Officer</FONT></TD></TR>
</TABLE>


<P STYLE="font: 10pt Times New Roman, Times, Serif; margin: 0pt 0; text-align: justify">&nbsp;</P>

<P STYLE="font: 10pt Times New Roman, Times, Serif; margin: 0pt 0; text-align: justify">&nbsp;</P>

<P STYLE="font: bold 10pt Times New Roman, Times, Serif; margin: 0pt 0; text-align: center">POWER OF ATTORNEY</P>

<P STYLE="font: bold 10pt Times New Roman, Times, Serif; margin: 0pt 0; text-align: center">&nbsp;</P>

<P STYLE="font: 10pt Times New Roman, Times, Serif; margin: 0pt 0; text-indent: 0.5in">KNOW ALL MEN BY THESE PRESENTS, that each
person whose signature appears below constitutes and appoints Kevin J. Zugibe, Stephen P. Mandracchia and Brian F. Coleman and
each of them, his or her true and lawful attorney-in-fact and agent, with full power and substitution and resubstitution, for him
or her or its and in his or her name, place and stead, in any and all capacities to sign any and all amendments (including, without
limitation, post-effective amendments) to this Registration Statement and any registration statement filed under Rule 462 under
the Securities Act of 1933, as amended, and to file the same, with all exhibits thereto, and other documents in connection therewith,
with authority to do and perform each and every act and thing requisite and necessary to be done in and about the premises as fully
to all intents and purposes as he might or could do in person, hereby ratifying and confirming all that said attorney-in-fact and
agent, or his substitute or substitutes, may lawfully do or cause to be done by virtue hereof.</P>

<P STYLE="font: 10pt Times New Roman, Times, Serif; margin: 0pt 0; text-indent: 0.5in">&nbsp;</P>

<P STYLE="font: 10pt Times New Roman, Times, Serif; margin: 0pt 0; text-indent: 0.5in">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:</P>

<P STYLE="font: 10pt Times New Roman, Times, Serif; margin: 0pt 0; text-indent: 0.5in">&nbsp;</P>

<TABLE CELLSPACING="0" CELLPADDING="0" STYLE="font: 10pt Times New Roman, Times, Serif; width: 100%; border-collapse: collapse">
<TR>
    <TD STYLE="vertical-align: top; width: 30%; text-decoration: underline; text-align: center"><B><U>Name</U></B></TD>
    <TD STYLE="width: 2%">&nbsp;</TD>
    <TD STYLE="vertical-align: top; width: 41%; text-decoration: underline; text-align: center"><B><U>Title</U></B></TD>
    <TD STYLE="width: 2%">&nbsp;</TD>
    <TD STYLE="vertical-align: top; width: 25%; text-decoration: underline; text-align: center"><B><U>Date</U></B></TD></TR>
<TR>
    <TD STYLE="vertical-align: top">&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD STYLE="vertical-align: top">&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD STYLE="vertical-align: top">&nbsp;</TD></TR>
<TR>
    <TD STYLE="vertical-align: top; border-bottom: black 1pt solid; text-align: justify">/s/ KEVIN J. ZUGIBE*</TD>
    <TD>&nbsp;</TD>
    <TD STYLE="vertical-align: top; text-align: justify">&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD STYLE="vertical-align: top; text-align: justify">&nbsp;</TD></TR>
<TR>
    <TD STYLE="vertical-align: top; text-align: justify">Kevin J. Zugibe</TD>
    <TD>&nbsp;</TD>
    <TD STYLE="vertical-align: top; text-align: justify">Chairman of the Board and Chief Executive Officer (Principal Executive Officer)</TD>
    <TD>&nbsp;</TD>
    <TD STYLE="vertical-align: top; text-align: center">December 8, 2016</TD></TR>
<TR>
    <TD STYLE="vertical-align: top; text-align: justify">&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD STYLE="vertical-align: top; text-align: justify">&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD STYLE="vertical-align: top; text-align: center">&nbsp;</TD></TR>
<TR>
    <TD STYLE="vertical-align: top; border-bottom: black 1pt solid; text-align: justify">/s/ NAT KRISHNAMURTI</TD>
    <TD>&nbsp;</TD>
    <TD STYLE="vertical-align: top; text-align: justify">&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD STYLE="vertical-align: top; text-align: justify">&nbsp;</TD></TR>
<TR>
    <TD STYLE="vertical-align: top; text-align: justify">Nat Krishnamurti</TD>
    <TD>&nbsp;</TD>
    <TD STYLE="vertical-align: top; text-align: justify">Chief Financial Officer (Principal Financial and Accounting Officer)</TD>
    <TD>&nbsp;</TD>
    <TD STYLE="vertical-align: top; text-align: center">December 8, 2016</TD></TR>
<TR>
    <TD STYLE="vertical-align: top; text-align: justify">&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD STYLE="vertical-align: top; text-align: justify">&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD STYLE="vertical-align: top; text-align: center">&nbsp;</TD></TR>
<TR>
    <TD STYLE="vertical-align: top; border-bottom: black 1pt solid; text-align: justify">/s/ VINCENT P. ABBATECOLA*</TD>
    <TD>&nbsp;</TD>
    <TD STYLE="vertical-align: top; text-align: justify">&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD STYLE="vertical-align: top; text-align: justify">&nbsp;</TD></TR>
<TR>
    <TD STYLE="vertical-align: top; text-align: justify">Vincent P. Abbatecola</TD>
    <TD>&nbsp;</TD>
    <TD STYLE="vertical-align: top; text-align: justify">Director</TD>
    <TD>&nbsp;</TD>
    <TD STYLE="vertical-align: top; text-align: center">December 8, 2016</TD></TR>
<TR>
    <TD STYLE="vertical-align: top; text-align: justify">&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD STYLE="vertical-align: top; text-align: justify">&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD STYLE="vertical-align: top; text-align: center">&nbsp;</TD></TR>
<TR>
    <TD STYLE="vertical-align: top; border-bottom: black 1pt solid; text-align: justify">/s/ BRIAN F. COLEMAN*</TD>
    <TD>&nbsp;</TD>
    <TD STYLE="vertical-align: top; text-align: justify">&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD STYLE="vertical-align: top; text-align: justify">&nbsp;</TD></TR>
<TR>
    <TD STYLE="vertical-align: top; text-align: justify">Brian F. Coleman</TD>
    <TD>&nbsp;</TD>
    <TD STYLE="vertical-align: top; text-align: justify">Director and President and Chief Operating Officer</TD>
    <TD>&nbsp;</TD>
    <TD STYLE="vertical-align: top; text-align: center">December 8, 2016</TD></TR>
<TR>
    <TD STYLE="vertical-align: top; text-align: justify">&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD STYLE="vertical-align: top; text-align: justify">&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD STYLE="vertical-align: top; text-align: center">&nbsp;</TD></TR>
</TABLE>

<P STYLE="margin: 0">&nbsp;</P>

<P STYLE="margin: 0"></P>

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    <DIV STYLE="page-break-before: always; margin-top: 6pt; margin-bottom: 12pt"><P STYLE="margin: 0pt">&nbsp;</P></DIV>
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<P STYLE="margin: 0">&nbsp;</P>

<TABLE CELLSPACING="0" CELLPADDING="0" STYLE="font: 10pt Times New Roman, Times, Serif; width: 100%; border-collapse: collapse">
<TR>
    <TD STYLE="vertical-align: top; text-decoration: underline; text-align: center; width: 30%"><B><U>Name</U></B></TD>
    <TD STYLE="width: 2%">&nbsp;</TD>
    <TD STYLE="vertical-align: top; text-decoration: underline; text-align: center; width: 41%"><B><U>Title</U></B></TD>
    <TD STYLE="width: 2%">&nbsp;</TD>
    <TD STYLE="vertical-align: top; text-decoration: underline; text-align: center; width: 25%"><B><U>Date</U></B></TD></TR>

<TR>
    <TD STYLE="vertical-align: top; text-align: justify">&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD STYLE="vertical-align: top; text-align: justify">&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD STYLE="vertical-align: top">&nbsp;</TD></TR>
<TR>
    <TD STYLE="vertical-align: top; border-bottom: black 1pt solid; text-align: justify; width: 30%">&nbsp;/s/ DOMINIC J. MONETTA*</TD>
    <TD STYLE="width: 2%">&nbsp;</TD>
    <TD STYLE="vertical-align: top; text-align: justify; width: 41%">&nbsp;</TD>
    <TD STYLE="width: 2%">&nbsp;</TD>
    <TD STYLE="vertical-align: top; width: 25%">&nbsp;</TD></TR>
<TR>
    <TD STYLE="vertical-align: top; text-align: justify">Dominic J. Monetta</TD>
    <TD>&nbsp;</TD>
    <TD STYLE="vertical-align: top; text-align: justify">Director</TD>
    <TD>&nbsp;</TD>
    <TD STYLE="vertical-align: top; text-align: center">December 8, 2016</TD></TR>
<TR>
    <TD STYLE="vertical-align: top; text-align: justify">&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD STYLE="vertical-align: top; text-align: justify">&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD STYLE="vertical-align: top; text-align: center">&nbsp;</TD></TR>
<TR>
    <TD STYLE="vertical-align: top; border-bottom: black 1pt solid">
        <P STYLE="font: 10pt Times New Roman, Times, Serif; margin: 0pt 0; text-align: justify"></P>
        <P STYLE="font: 10pt Times New Roman, Times, Serif; margin: 0pt 0; text-align: justify">&nbsp;/s/ OTTO C. MORCH*</P></TD>
    <TD>&nbsp;</TD>
    <TD STYLE="vertical-align: top; text-align: justify">&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD STYLE="vertical-align: top">&nbsp;</TD></TR>
<TR>
    <TD STYLE="vertical-align: top; text-align: justify">Otto C. Morch</TD>
    <TD>&nbsp;</TD>
    <TD STYLE="vertical-align: top; text-align: justify">Director</TD>
    <TD>&nbsp;</TD>
    <TD STYLE="vertical-align: top; text-align: center">December 8, 2016</TD></TR>
<TR>
    <TD STYLE="vertical-align: top; text-align: justify">&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD STYLE="vertical-align: top; text-align: justify">&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD STYLE="vertical-align: top; text-align: center">&nbsp;</TD></TR>
<TR>
    <TD STYLE="vertical-align: top; border-bottom: black 1pt solid; text-align: justify">/s/ RICHARD PARRILLO*</TD>
    <TD>&nbsp;</TD>
    <TD STYLE="vertical-align: top; text-align: justify">&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD STYLE="vertical-align: top">&nbsp;</TD></TR>
<TR>
    <TD STYLE="vertical-align: top; text-align: justify">Richard Parrillo</TD>
    <TD>&nbsp;</TD>
    <TD STYLE="vertical-align: top; text-align: justify">Director</TD>
    <TD>&nbsp;</TD>
    <TD STYLE="vertical-align: top; text-align: center">December 8, 2016</TD></TR>
<TR>
    <TD STYLE="vertical-align: top; text-align: justify">&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD STYLE="vertical-align: top; text-align: justify">&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD STYLE="vertical-align: top; text-align: center">&nbsp;</TD></TR>
<TR>
    <TD STYLE="vertical-align: top; border-bottom: black 1pt solid">
        <P STYLE="font: 10pt Times New Roman, Times, Serif; margin: 0pt 0; text-align: justify">&nbsp;/s/ ERIC A. PROUTY*</P></TD>
    <TD>&nbsp;</TD>
    <TD STYLE="vertical-align: top; text-align: justify">&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD STYLE="vertical-align: top">&nbsp;</TD></TR>
<TR>
    <TD STYLE="vertical-align: top; text-align: justify">Eric A. Prouty</TD>
    <TD>&nbsp;</TD>
    <TD STYLE="vertical-align: top; text-align: justify">Director</TD>
    <TD>&nbsp;</TD>
    <TD STYLE="vertical-align: top; text-align: center">December 8, 2016</TD></TR>
</TABLE>
<P STYLE="font: 10pt Times New Roman, Times, Serif; margin: 0pt 0; text-align: justify">&nbsp;</P>

<P STYLE="font: 10pt Times New Roman, Times, Serif; margin: 0pt 0; text-align: justify">&nbsp;</P>

<TABLE CELLSPACING="0" CELLPADDING="0" STYLE="width: 100%; font: 10pt Times New Roman, Times, Serif; border-collapse: collapse">
<TR STYLE="vertical-align: top">
    <TD NOWRAP STYLE="width: 2%; text-align: justify"><FONT STYLE="font-family: Times New Roman, Times, Serif; font-size: 10pt">*By:</FONT>&nbsp;&nbsp;</TD>
    <TD STYLE="width: 48%; text-align: justify; border-bottom: Black 1pt solid"><FONT STYLE="font-family: Times New Roman, Times, Serif; font-size: 10pt">/s/ Stephen P. Mandracchia</FONT></TD>
    <TD STYLE="width: 50%; text-align: justify">&nbsp;</TD></TR>
<TR STYLE="vertical-align: top">
    <TD COLSPAN="2" STYLE="text-align: justify"><FONT STYLE="font-family: Times New Roman, Times, Serif; font-size: 10pt">Stephen P. Mandracchia</FONT></TD>
    <TD STYLE="text-align: justify">&nbsp;</TD></TR>
<TR STYLE="vertical-align: top">
    <TD COLSPAN="2"><FONT STYLE="font-family: Times New Roman, Times, Serif; font-size: 10pt">Attorney-in-Fact</FONT></TD>
    <TD>&nbsp;</TD></TR>
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<P STYLE="font: 10pt Times New Roman, Times, Serif; margin: 0pt 0; text-align: justify">&nbsp;</P>


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<P STYLE="font: bold 10pt Times New Roman, Times, Serif; margin: 0pt 0; text-align: center">&nbsp;</P>

<P STYLE="font: bold 10pt Times New Roman, Times, Serif; margin: 0pt 0; text-align: center">EXHIBIT INDEX</P>

<P STYLE="font: bold 10pt Times New Roman, Times, Serif; margin: 0pt 0; text-align: center">&nbsp;</P>

<P STYLE="font: 10pt Times New Roman, Times, Serif; margin: 0pt 0; text-align: justify">&nbsp;</P>

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<TR STYLE="vertical-align: top">
    <TD STYLE="padding-bottom: 12pt; text-align: justify"><B><U>Number</U>&nbsp;&nbsp;</B></TD>
    <TD STYLE="padding-bottom: 12pt; text-align: justify"><B><U>Exhibit Title</U></B></TD></TR>
<TR STYLE="vertical-align: top">
    <TD STYLE="width: 8%; padding-bottom: 12pt; text-align: justify">5</TD>
    <TD STYLE="width: 92%; padding-bottom: 12pt; text-align: justify">Opinion of Stephen P. Mandracchia.</TD></TR>
<TR STYLE="vertical-align: top">
    <TD STYLE="padding-bottom: 12pt; text-align: justify">23.1</TD>
    <TD STYLE="padding-bottom: 12pt; text-align: justify">Consent of BDO USA, LLP.</TD></TR>
<TR STYLE="vertical-align: top">
    <TD STYLE="padding-bottom: 12pt; text-align: justify">23.2</TD>
    <TD STYLE="padding-bottom: 12pt; text-align: justify">Consent of Stephen P. Mandracchia (included in Exhibit 5).</TD></TR>
<TR STYLE="vertical-align: top">
    <TD STYLE="text-align: justify">24</TD>
    <TD STYLE="text-align: justify">Power of Attorney (included on the signature page of the Registration Statement).</TD></TR>
</TABLE>
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<TYPE>EX-5
<SEQUENCE>2
<FILENAME>v454715_ex5.htm
<DESCRIPTION>EXHIBIT 5
<TEXT>
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<P STYLE="font: 10pt Times New Roman, Times, Serif; margin: 0pt 0; text-align: right">&nbsp;</P>

<P STYLE="font: 10pt Times New Roman, Times, Serif; margin: 0pt 0; text-align: right">Exhibit 5</P>

<P STYLE="font: 10pt Times New Roman, Times, Serif; margin: 0pt 0">&nbsp;</P>

<P STYLE="font: 10pt Times New Roman, Times, Serif; margin: 0pt 0; text-align: center">Hudson Technologies, Inc.</P>

<P STYLE="font: 10pt Times New Roman, Times, Serif; margin: 0pt 0; text-align: center">P.O. Box 1541</P>

<P STYLE="font: 10pt Times New Roman, Times, Serif; margin: 0pt 0; text-align: center">One Blue Hill Plaza</P>

<P STYLE="font: 10pt Times New Roman, Times, Serif; margin: 0pt 0; text-align: center">Pearl River, NY 10965</P>

<P STYLE="font: 10pt Times New Roman, Times, Serif; margin: 0pt 0; text-align: center">&nbsp;</P>

<P STYLE="font: 10pt Times New Roman, Times, Serif; margin: 0pt 0 0pt 3.5in; text-align: right">December 8, 2016</P>

<P STYLE="font: 10pt Times New Roman, Times, Serif; margin: 0pt 0">&nbsp;</P>

<P STYLE="font: 10pt Times New Roman, Times, Serif; margin: 0pt 0">Hudson Technologies, Inc.<BR>
P.O. Box 1541</P>

<P STYLE="font: 10pt Times New Roman, Times, Serif; margin: 0pt 0">One Blue Hill Plaza<BR>
Pearl River, NY 10965</P>

<P STYLE="font: 10pt Times New Roman, Times, Serif; margin: 0pt 0 0pt 1.5in; text-indent: -0.5in">&nbsp;</P>

<TABLE CELLSPACING="0" CELLPADDING="0" STYLE="font: 10pt Times New Roman, Times, Serif; width: 100%">
<TR STYLE="vertical-align: top">
    <TD STYLE="width: 96px">&nbsp;</TD>
    <TD STYLE="width: 48px">Re:</TD>
    <TD STYLE="text-decoration: underline"><U>Hudson Technologies, Inc. - Registration Statement on Form S-3</U></TD></TR>
</TABLE>
<P STYLE="font: 10pt Times New Roman, Times, Serif; margin: 0pt 0">&nbsp;</P>

<P STYLE="font: 10pt Times New Roman, Times, Serif; margin: 0pt 0">Gentlemen:</P>

<P STYLE="font: 10pt Times New Roman, Times, Serif; margin: 0pt 0; text-indent: 0.5in">&nbsp;</P>

<P STYLE="font: 10pt Times New Roman, Times, Serif; margin: 0pt 0; text-indent: 0.5in">In my role as Vice President Legal and Regulatory
of Hudson Technologies, Inc., a New York corporation (the &ldquo;Company&rdquo;), I also serve in the capacity as its general counsel.
You have requested my opinion in connection with the Company&rsquo;s Registration Statement on Form S-3 (the &ldquo;Registration
Statement&rdquo;) under the Securities Act of 1933, as amended (the &ldquo;Act&rdquo;), relating to (A) the proposed offer and
sale from time to time of up to $1,750,000 in aggregate amount of any of the following: (i) shares of common stock, par value $0.01
per share, of the Company (the &ldquo;Common Stock&rdquo;), (ii) shares of one or more series of preferred stock, par value $0.01
per share, of the Company (the &ldquo;Preferred Stock&rdquo;), (iii) one or more debt securities of the Company (the &ldquo;Debt
Securities&rdquo;), (iv) warrants to purchase Common Stock or Preferred Stock (the &ldquo;Warrants&rdquo;) and (v) units comprised
of one or more of shares of Common Stock, shares of Preferred Stock, Debt Securities and Warrants (the &ldquo;Units&rdquo; and,
collectively with the Common Stock, Preferred Stock, Debt Securities and Warrants, the &ldquo;Securities&rdquo;).</P>

<P STYLE="font: 10pt Times New Roman, Times, Serif; margin: 0pt 0; text-indent: 0.5in">&nbsp;</P>

<P STYLE="font: 10pt Times New Roman, Times, Serif; margin: 0pt 0; text-indent: 0.5in">In rendering the opinions set forth below,
I have examined originals or copies, certified or otherwise, identified to my satisfaction of such documents and corporate and
public records as I deem necessary as a basis for the opinions hereinafter expressed. With respect to such examination, I have
assumed the genuineness of all signatures appearing on all documents presented to me as originals, and the conformity to the originals
of all documents presented to me as conformed or reproduced copies. Where factual matters relevant to such opinion were not independently
established, I have relied upon certificates of executive officers and responsible employees and agents of the Company.</P>

<P STYLE="font: 10pt Times New Roman, Times, Serif; margin: 0pt 0; text-indent: 0.5in">&nbsp;</P>


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<P STYLE="font: 10pt Times New Roman, Times, Serif; margin: 0pt 0">&nbsp;</P>

<P STYLE="font: 10pt Times New Roman, Times, Serif; margin: 0pt 0">Hudson Technologies, Inc.</P>

<P STYLE="font: 10pt Times New Roman, Times, Serif; margin: 0pt 0">December 8, 2016</P>

<P STYLE="font: 10pt Times New Roman, Times, Serif; margin: 0pt 0">Page 2</P>

<P STYLE="font: 10pt Times New Roman, Times, Serif; margin: 0pt 0; text-indent: 0.5in">&nbsp;</P>

<P STYLE="font: 10pt Times New Roman, Times, Serif; margin: 0pt 0; text-indent: 0.5in">For purposes of this opinion letter, I have
also assumed that (a)&nbsp;the Registration Statement, and any amendments thereto (including post-effective amendments), will have
become effective and such effectiveness will not have been terminated or rescinded, (b) any applicable prospectus supplement will
have been prepared and filed with the Securities and Exchange Commission describing the Securities offered thereby, (c) all Securities
will be offered and sold in compliance with applicable federal and state securities laws and in the manner stated in the Registration
Statement and any appropriate prospectus supplement, (d) any definitive purchase, underwriting or similar agreement with respect
to any Securities offered will have been duly authorized and validly executed and delivered by the parties thereto, (e) any Securities
issuable upon conversion, exchange, redemption or exercise of any Securities being offered will have been duly authorized, created
and, if appropriate, reserved for issuance upon such conversion, exchange, redemption or exercise, (f) at the time of any offering
or sale of any shares of Common Stock or Preferred Stock or Warrants to purchase shares of Common Stock or Preferred Stock, there
will be sufficient shares of Common Stock and/or Preferred Stock, as applicable, authorized and unissued under the Company&rsquo;s
then operative certificate of incorporation, as amended by a Certificate of Amendment (defined below) in respect of Preferred Stock
as applicable (the &ldquo;Certificate of Incorporation&rdquo;), and not otherwise reserved for issuance, (g) at the time of issuance
or sale of the Securities, the Company will be validly existing and duly qualified and in good standing under the laws of its jurisdiction
of incorporation, and have the necessary corporate power for such issuance, (h) at the time of issuance or sale of the Securities,
the Certificate of Incorporation and then operative by-laws of the Company (the &ldquo;By-Laws&rdquo; and collectively with the
Certificate of Incorporation, the &ldquo;Charter Documents&rdquo;) are in full force and effect and, except as contemplated hereby,
have not been amended, restated, supplemented or otherwise altered since the date hereof, (i) any applicable indenture relating
to the issuance of the Debt Securities and any Warrant Agreement (defined below) or Unit Agreement (defined below) will be duly
authorized, executed and delivered by the parties thereto and constitute legally valid and binding obligations of the parties thereto,
enforceable against each of them in accordance with their respective terms, and (j) that the terms, execution and delivery of the
Securities (i) do not result in breaches of, or defaults under, agreements or instruments to which the Company and any selling
shareholders is bound or violations of applicable statutes, rules, regulations or court or governmental orders, and (ii) comply
with any applicable requirement or restriction imposed by any court or governmental body having jurisdiction over the Company and
any selling shareholders. I have further assumed the legal capacity of natural persons, and I have assumed that each party to the
documents I have examined or relied on has the legal capacity or authority and has satisfied all legal requirements that are applicable
to that party to the extent necessary to make such documents enforceable against that party. I have not verified any of the foregoing
assumptions.</P>

<P STYLE="font: 10pt Times New Roman, Times, Serif; margin: 0pt 0; text-indent: 0.5in">&nbsp;</P>

<P STYLE="font: 10pt Times New Roman, Times, Serif; margin: 0pt 0; text-indent: 0.5in">The opinions expressed in this opinion letter
are limited to the laws of the State of New York. My opinions are based on these laws as in effect on the date hereof. I express
no opinion as to whether the laws of any other jurisdiction are applicable to the subject matter hereof. I am not opining on, and
I assume no responsibility for, the applicability for, the applicability to or effect on any of the matters covered herein of (i)
any other laws; (ii) the laws of any other jurisdiction; (iii) or the laws of any county. I am not rendering any opinion as to
compliance with any federal or state law, rule or regulation relating to securities, or to the sale or issuance thereof.</P>

<P STYLE="font: 10pt Times New Roman, Times, Serif; margin: 0pt 0; text-indent: 0.5in">&nbsp;</P>


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<P STYLE="font: 10pt Times New Roman, Times, Serif; margin: 0pt 0">&nbsp;</P>

<P STYLE="font: 10pt Times New Roman, Times, Serif; margin: 0pt 0">Hudson Technologies, Inc.</P>

<P STYLE="font: 10pt Times New Roman, Times, Serif; margin: 0pt 0">December 8, 2016</P>

<P STYLE="font: 10pt Times New Roman, Times, Serif; margin: 0pt 0">Page 3</P>

<P STYLE="font: 10pt Times New Roman, Times, Serif; margin: 0pt 0; text-indent: 0.5in">&nbsp;</P>

<P STYLE="font: 10pt Times New Roman, Times, Serif; margin: 0pt 0; text-indent: 0.5in">Based upon and subject to the foregoing
and the other matters set forth herein, it is my opinion that:</P>

<P STYLE="font: 10pt Times New Roman, Times, Serif; margin: 0pt 0; text-indent: 0.5in">&nbsp;</P>

<P STYLE="font: 10pt Times New Roman, Times, Serif; margin: 0pt 0; text-indent: 0.5in">(1)&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;With
respect to shares of Common Stock offered by the Company under the Registration Statement, when (a) the Company has taken all necessary
action to authorize and approve the issuance thereof and related matters, and (b) certificates representing the shares of Common
Stock have been duly executed, countersigned, registered and delivered, or if uncertificated, valid book-entry notations have been
made in the share register of the Company, in each case in accordance with the Charter Documents, either (i) against payment therefor
in an amount not less than the par value thereof or such other consideration determined by the Company&rsquo;s Board of Directors
and permitted under the New York Business Corporation Law and in the manner contemplated by the Registration Statement and/or any
applicable prospectus supplement and in accordance with the provisions of the applicable definitive purchase, underwriting or similar
agreement, if any, approved by the Company or (ii) upon conversion, exchange, redemption or exercise of any other Security in accordance
with the terms of such Security or the instrument (including for purposes hereof a Certificate of Amendment) governing such Security
as approved by the Company, for the consideration approved by the Company (in an amount not less than the par value thereof or
such other consideration determined by the Company&rsquo;s Board of Directors and permitted under the New York Business Corporation
Law), the shares of Common Stock will be duly authorized, validly issued, fully paid and non-assessable.</P>

<P STYLE="font: 10pt Times New Roman, Times, Serif; margin: 0pt 0; text-indent: 0.5in">&nbsp;</P>

<P STYLE="font: 10pt Times New Roman, Times, Serif; margin: 0pt 0; text-indent: 0.5in">(2)&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;With
respect to shares of one or more series of Preferred Stock offered by the Company under the Registration Statement, when (a) the
Company has taken all necessary action to authorize and approve the issuance thereof and related matters, including the adoption
of an appropriate certificate of amendment to the Certificate of Incorporation relating to such series of Preferred Stock which
has been properly filed with the Secretary of State of the State of New York (&ldquo;Certificate of Amendment&rdquo;), and (b)
certificates representing the shares of Preferred Stock have been duly executed, countersigned, registered and delivered, or if
uncertificated, valid book-entry notations have been made in the share register of the Company, in each case in accordance with
the Charter Documents, either (i) against payment therefor in an amount not less than the par value thereof or such other consideration
determined by the Company&rsquo;s Board of Directors and permitted under the New York Business Corporation Law and in the manner
contemplated by the Registration Statement and/or any applicable prospectus supplement and in accordance with the provisions of
the applicable definitive purchase, underwriting or similar agreement, if any, approved by the Company or (ii) upon conversion,
exchange, redemption or exercise of any other Security in accordance with the terms of such Security or the instrument (including
for purposes hereof a Certificate of Amendment) governing such Security as approved by the Company, for the consideration approved
by the Company (in an amount not less than the par value thereof or such other consideration determined by the Company&rsquo;s
Board of Directors and permitted under the New York Business Corporation Law), the shares of Preferred Stock will be duly authorized,
validly issued, fully paid and non-assessable.</P>

<P STYLE="font: 10pt Times New Roman, Times, Serif; margin: 0pt 0; text-indent: 0.5in">&nbsp;</P>


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<P STYLE="font: 10pt Times New Roman, Times, Serif; margin: 0pt 0">&nbsp;</P>

<P STYLE="font: 10pt Times New Roman, Times, Serif; margin: 0pt 0">Hudson Technologies, Inc.</P>

<P STYLE="font: 10pt Times New Roman, Times, Serif; margin: 0pt 0">December 8, 2016</P>

<P STYLE="font: 10pt Times New Roman, Times, Serif; margin: 0pt 0">Page 4</P>

<P STYLE="font: 10pt Times New Roman, Times, Serif; margin: 0pt 0; text-indent: 0.5in">&nbsp;</P>

<P STYLE="font: 10pt Times New Roman, Times, Serif; margin: 0pt 0; text-indent: 0.5in">(3)&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;With
respect to Debt Securities, when (a) an applicable indenture, if any, or any necessary amendment or supplement thereto or other
agreement in respect thereof, if any, has been duly authorized and validly executed and delivered by the Company and the trustee
thereunder, (b) any applicable indenture, if required, has been duly qualified under the Trust Indenture Act of 1939, as amended,
if qualification is required thereunder, (c) the specific terms and the issuance and sale of any particular Debt Security have
been duly established in accordance with the applicable indenture, if any, or any necessary amendment thereto or other agreement
in respect thereof, if any, and authorized by all necessary action of the Company, and (d) any such Debt Security has been duly
executed, issued, authenticated (if required) and delivered by or on behalf of the Company as contemplated by the Registration
Statement and/or any applicable prospectus supplement either (i) against payment therefor in accordance with the provisions of
the applicable indenture and/or any other agreement or instrument binding upon the Company and the provisions of the applicable
definitive purchase, underwriting or similar agreement approved by the Company and in the manner contemplated by the Registration
Statement and/or any applicable prospectus supplement or (ii) upon conversion, exchange, redemption or exercise of any other Security
in accordance with the terms of such Security or the instrument (including for purposes hereof a Certificate of Amendment) governing
such Security as approved by the Company, for the consideration approved by the Company, such Debt Securities will constitute valid
and binding obligations of the Company, enforceable against the Company in accordance with their terms.</P>

<P STYLE="font: 10pt Times New Roman, Times, Serif; margin: 0pt 0; text-indent: 0.5in">&nbsp;</P>

<P STYLE="font: 10pt Times New Roman, Times, Serif; margin: 0pt 0; text-indent: 0.5in">(4)&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;With
respect to Warrants offered by the Company under the Registration Statement, when (a) the Company has taken all necessary action
to authorize and approve the creation of and the issuance and terms of the Warrants, the terms of the offering thereof and related
matters, (b) a warrant agreement in respect thereof (a &ldquo;Warrant Agreement&rdquo;) has been duly authorized, executed and
delivered by the Company in accordance with applicable law and (c) the Warrants have been duly executed and delivered against payment
therefor in accordance with the provisions of the Warrant Agreement and in the manner contemplated by the Registration Statement
and/or any applicable prospectus supplement (assuming the securities issuable upon exercise of the Warrants have been duly authorized
and reserved for issuance by all necessary corporate action and in accordance with applicable law), the Warrants will constitute
valid and binding obligations of the Company, enforceable against the Company in accordance with their terms.</P>

<P STYLE="font: 10pt Times New Roman, Times, Serif; margin: 0pt 0; text-indent: 0.5in">&nbsp;</P>


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<P STYLE="font: 10pt Times New Roman, Times, Serif; margin: 0pt 0">&nbsp;</P>

<P STYLE="font: 10pt Times New Roman, Times, Serif; margin: 0pt 0">Hudson Technologies, Inc.</P>

<P STYLE="font: 10pt Times New Roman, Times, Serif; margin: 0pt 0">December 8, 2016</P>

<P STYLE="font: 10pt Times New Roman, Times, Serif; margin: 0pt 0">Page 5</P>

<P STYLE="font: 10pt Times New Roman, Times, Serif; margin: 0pt 0; text-indent: 0.5in">&nbsp;</P>

<P STYLE="font: 10pt Times New Roman, Times, Serif; margin: 0pt 0; text-indent: 0.5in">(5)&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;With
respect to Units, assuming that (a) any Debt Securities that form a part of such Units constitute valid and binding obligations
of the Company, enforceable against the Company in accordance with their terms, as contemplated in numbered paragraph 3 above,
(b) any Warrants that form a part of such Units constitute valid and binding obligations of the Company in accordance with their
terms, as contemplated in numbered paragraph 4 above, and (c) any shares of Common Stock or Preferred Stock that form a part of
such Units are validly issued, fully paid and nonassessable, as contemplated in numbered paragraphs 1 and 2 above, respectively,
when (i) the Company has taken all necessary corporate action to approve the creation of and the issuance and terms of the Units
(including the Securities which comprise such Units), the terms of the offering thereof and related matters, (ii) any applicable
unit agreement has been duly authorized, executed and delivered by the Company in accordance with applicable law (a &ldquo;Unit
Agreement&rdquo;), and (iii) the Units or certificates representing the Units, as the case may be, have been delivered against
payment therefor in accordance with the provisions of any applicable Unit Agreement or purchase or similar agreement approved by
the Company and in the manner contemplated by the Registration Statement and/or any applicable prospectus supplement, the Units
will constitute valid and binding obligations of the Company, enforceable against the Company in accordance with their terms.</P>

<P STYLE="font: 10pt Times New Roman, Times, Serif; margin: 0pt 0; text-indent: 0.5in">&nbsp;</P>

<P STYLE="font: 10pt Times New Roman, Times, Serif; margin: 0pt 0; text-indent: 0.5in">I express no opinion regarding (i) the validity
or enforceability of any provisions that purport to waive or not give effect to rights or notices, defenses, subrogation or other
rights or benefits that cannot be effectively waived under applicable law, (ii) the enforceability of indemnification provisions
to the extent they purport to relate to liabilities resulting from or based upon negligence or any violation of federal or state
securities or blue sky laws, (iii) any provision for liquidated damages, default interest, late charges, monetary penalties, make-whole
premiums or other economic remedies to the extent such provisions are deemed to constitute a penalty, (iv) consents to, or restrictions
upon, governing law, jurisdiction, venue, arbitration, remedies or judicial relief, (v) any provision requiring the payment of
attorneys&rsquo; fees, where such payment is contrary to law or public policy, (vi) provisions for exclusivity, election or cumulation
of rights or remedies, (vii) provisions authorizing or validating conclusive or discretionary determinations, (viii) grants of
setoff rights, (ix) the availability of equitable remedies to any person or entity including, but not limited to, specific performance
and injunctive relief; (x)&nbsp;the effect of bankruptcy, reorganization, insolvency, fraudulent conveyance, fraudulent transfer,
moratorium and other similar laws or equitable principles affecting creditors&rsquo; rights or remedies (whether applied by a court
of law or equity), (xi) the effect of applicable law and court decisions which may hereafter limit or render unenforceable certain
rights or remedies of any person or entity and (xii) the severability, if invalid, of provisions to the foregoing effect.</P>

<P STYLE="font: 10pt Times New Roman, Times, Serif; margin: 0pt 0; text-indent: 0.5in">&nbsp;</P>


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<P STYLE="font: 10pt Times New Roman, Times, Serif; margin: 0pt 0">&nbsp;</P>

<P STYLE="font: 10pt Times New Roman, Times, Serif; margin: 0pt 0">Hudson Technologies, Inc.</P>

<P STYLE="font: 10pt Times New Roman, Times, Serif; margin: 0pt 0">December 8, 2016</P>

<P STYLE="font: 10pt Times New Roman, Times, Serif; margin: 0pt 0">Page 6</P>

<P STYLE="font: 10pt Times New Roman, Times, Serif; margin: 0pt 0; text-indent: 0.5in">&nbsp;</P>

<P STYLE="font: 10pt Times New Roman, Times, Serif; margin: 0pt 0; text-indent: 0.5in">I hereby consent to the use of this opinion
as Exhibit 5 to the Registration Statement, and to the use of my name as your counsel under &ldquo;Legal Matters&rdquo; in the
Prospectus constituting a part of the Registration Statement. In giving this consent, I do not thereby concede that I come within
the categories of persons whose consent is required by the Act or the General Rules and Regulations promulgated thereunder. I assume
no obligation to update or supplement any of the opinions set forth herein to reflect any changes of law or fact that may occur
after the Registration Statement becomes effective.</P>

<P STYLE="font: 10pt Times New Roman, Times, Serif; margin: 0pt 0 0pt 3.5in">&nbsp;</P>

<TABLE CELLSPACING="0" CELLPADDING="0" STYLE="font: 10pt Times New Roman, Times, Serif; width: 100%; border-collapse: collapse">
<TR STYLE="vertical-align: top">
    <TD STYLE="width: 50%">&nbsp;</TD>
    <TD STYLE="width: 50%">Very truly yours,</TD></TR>
<TR STYLE="vertical-align: top">
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD></TR>
<TR STYLE="vertical-align: top">
    <TD>&nbsp;</TD>
    <TD>/s/ Stephen P. Mandracchia</TD></TR>
<TR STYLE="vertical-align: top">
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD></TR>
<TR STYLE="vertical-align: top">
    <TD>&nbsp;</TD>
    <TD>Stephen P. Mandracchia, Esq.</TD></TR>
</TABLE>
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<TYPE>EX-23.1
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<FILENAME>v454715_ex23-1.htm
<DESCRIPTION>EXHIBIT 23.1
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<P STYLE="font: 10pt Times New Roman, Times, Serif; margin: 0pt 0; text-align: right">&nbsp;</P>

<P STYLE="font: 10pt Times New Roman, Times, Serif; margin: 0pt 0; text-align: right">Exhibit 23.1</P>

<P STYLE="font: 10pt Times New Roman, Times, Serif; margin: 0pt 0">&nbsp;</P>

<P STYLE="font: 10pt Times New Roman, Times, Serif; margin: 0pt 0; text-align: center; background-color: white"><U>Consent of Independent
Registered Public Accounting Firm</U></P>

<P STYLE="font: 10pt Times New Roman, Times, Serif; margin: 0pt 0; text-align: center; background-color: white">&nbsp;</P>

<P STYLE="font: 10pt Times New Roman, Times, Serif; margin: 0pt 0 0pt 1.2pt; background-color: white">Hudson Technologies, Inc.</P>

<P STYLE="font: 10pt Times New Roman, Times, Serif; margin: 0pt 0 0pt 1.2pt; background-color: white">Pearl River, NY</P>

<P STYLE="font: 10pt Times New Roman, Times, Serif; margin: 0pt 0 0pt 0.5pt; text-align: justify; background-color: white">&nbsp;</P>

<P STYLE="font: 10pt Times New Roman, Times, Serif; margin: 0pt 0 0pt 0.5pt; text-align: justify; background-color: white">We hereby
consent to the incorporation by reference in the Registration Statement of Hudson Technologies, Inc. on Form S-3 MEF filed pursuant
to Rule 462(b) under the Securities Act of 1933 of our reports dated March 11, 2016 relating to the consolidated financial statements
and the effectiveness of Hudson Technologies Inc.&rsquo;s internal control over financial reporting, which appear in the Company's
Annual Report on Form 10-K for the year ended December 31, 2015.</P>

<P STYLE="font: 10pt Times New Roman, Times, Serif; margin: 0pt 0 0pt 0.5pt; text-align: justify; background-color: white">&nbsp;</P>

<P STYLE="font: 10pt Times New Roman, Times, Serif; margin: 0pt 0 0pt 0.5pt; text-align: justify; background-color: white">We also
consent to the reference to us under the caption &quot;Experts&quot; in the Prospectus incorporated by reference into such Registration
Statement.</P>

<P STYLE="font: 10pt Times New Roman, Times, Serif; margin: 0pt 0 0pt 0.5pt; text-align: justify; background-color: white">&nbsp;</P>

<P STYLE="font: 10pt Times New Roman, Times, Serif; margin: 0pt 0; background-color: white">/s/ BDO USA, LLP</P>

<P STYLE="font: 10pt Times New Roman, Times, Serif; margin: 0pt 0; background-color: white">&nbsp;</P>

<P STYLE="font: 10pt Times New Roman, Times, Serif; margin: 0pt 0; background-color: white">Stamford, CT</P>

<P STYLE="font: 10pt Times New Roman, Times, Serif; margin: 0pt 0; background-color: white">&nbsp;</P>

<P STYLE="font: 10pt Times New Roman, Times, Serif; margin: 0pt 0; background-color: white">December 7, 2016</P>

<P STYLE="font: 10pt Times New Roman, Times, Serif; margin: 0pt 0">&nbsp;</P>

<P STYLE="font: 10pt Times New Roman, Times, Serif; margin: 0pt 0"></P>

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<P STYLE="font: 10pt Times New Roman, Times, Serif; margin: 0pt 0">&nbsp;</P>


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