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                                                                       EXHIBIT 5

                             MCDERMOTT, WILL & EMERY
                              50 ROCKEFELLER PLAZA
                            NEW YORK, NEW YORK 10020


   
                                                              October 22, 1998
    

KTI, Inc.
7000 Boulevard East
Guttenberg, New Jersey 07093

   
         Re: Resale of up to an aggregate of 2,930,291 shares of common stock,
         no par value (the "Common Stock"), of KTI, Inc., a New Jersey
         corporation (the "Company"), consisting of (a) 1,714,285 shares of
         Common Stock previously issued by the Company (the "FCR Issued Shares")
         to the securityholders (the "Holders") of FCR, Inc. ("FCR") in
         connection with the merger (the "Merger") of FCR with and into a
         subsidiary of the Company, (b) up to 251,289 shares of Common Stock
         issuable to the Holders as an additional payment in connection with the
         Merger based upon the earnings of FCR (the "Earnout Shares"), (c)
         154,718 shares of Common Stock issued in connection with the
         acquisition of Atlantic Coast Fibers, Inc and First State Recycling,
         Inc. (the "Acquisition Issued Shares"), (d) 205,874 shares of Common
         Stock previously issued upon exercise of warrants and options (the
         "Issued Shares"), (e) 65,000 shares of Common Stock underlying warrants
         issued by the Company (the "Warrant Shares"), and (f) 539,125 shares of
         Common Stock underlying options issued to employees of the Company (the
         "Option Shares")
    

Ladies and Gentlemen:

         We have acted as your special counsel in connection with the
preparation and filing of a Registration Statement on Form S-3 (the
"Registration Statement") under the Securities Act of 1933, as amended (the
"Securities Act"), of the above-captioned securities, which, in the case of the
Earnout Shares, may be issued as an additional payment to the Holders in
connection with the Merger and, in the case of the Warrant Shares and Options,
may be issued upon exercise of warrants and options, and, in each case, then
offered for sale from time to time by selling shareholders.

         In arriving at the opinions expressed below we have examined the
Registration Statement, the Agreement and Plan of Merger, dated July 22, 1998
(the "Merger Agreement"), by and among the Company, KTI Acquisition Sub, Inc.,
FCR and the Holders, the acquisition agreements relating to Atlantic Coast
Fibers, Inc. and First State Recycling, Inc., the warrant agreements relating to
the Warrant Shares (the "Warrant Agreements"), the option agreements relating to
the Option Shares (the "Option Agreements"), resolutions of the Board of
Directors of the Company relating to the issuance of the above-referenced
securities, and such other documents as we have deemed necessary to enable us to
express the opinions hereinafter set forth. We have also reviewed such questions
of law as we considered necessary or appropriate for the purposes of such
opinions. In addition, we have examined and relied, to the extent we deemed
proper, on certificates of officers of the Company as to factual matters, on the
originals or copies certified or otherwise identified to our satisfaction of all
such corporate records of the Company and such other instruments and
certificates of public officials and other persons as we have deemed 
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appropriate. In our examination, we have assumed the authenticity of all
documents submitted to us as originals, the conformity to the original documents
of all documents submitted to as copies, and the genuineness of all signatures
on documents reviewed by us and the legal capacity of natural persons.

         Members of our firm are admitted to the bar of the State of New York.
We express no opinion as to the laws of any jurisdiction other than the laws of
the State of New York and, to the extent specifically referred to herein, the
New Jersey Business Corporation Act (the "NJBCA"). While we are not licensed to
practice law in the State of New Jersey, we have reviewed applicable provisions
of the NJBCA as we have deemed appropriate in connection with the opinions
expressed herein. Except as described, we have neither examined nor do we
express any opinion with respect to New Jersey Law.

         Based upon and subject to the foregoing, we are of the opinion that,
the FCR Issued Shares, the Acquisition Issued Shares and the Issued Shares are,
and the Earnout Shares, Warrant Shares and Option Shares, when issued in
accordance with the terms of the Merger Agreement, Warrant Agreements and Option
Agreements, respectively, will be, legally issued, fully paid and
non-assessable.

         We hereby consent to the filing of this opinion as an exhibit to the
Registration Statement and to the reference to us under the caption "Legal
Matters" in the Prospectus forming a part of the Registration Statement. In
giving this consent, we do not thereby admit that we are within the category of
persons whose consent is required under Section 7 of the Securities Act and the
rules and regulations of the Securities and Exchange Commission thereunder.

                                             Very truly yours,

                                             /s/ McDermott, Will & Emery