EXHIBIT 5.1


                  [Wachtell, Lipton, Rosen & Katz Letterhead]
                               February 13, 1998

W. R. Grace & Co.
One Town Center Road
Boca Raton, Florida  33486

               Re:  Registration Statement on Form S-4 of
                    W. R. Grace & Co.

Ladies and Gentlemen:

               We have acted as special counsel to W. R. Grace & Co., a
Delaware corporation ("Grace"), in connection with the above captioned
Registration Statement on Form S-4 (the "Registration Statement") being filed
today with the Securities and Exchange Commission (the "Commission") under the
Securities Act of 1933, as amended (the "1933 Act"), with respect to:  (1) the
shares of common stock, par value $.10 per share, of Grace ("New Sealed Air
Common Stock") and the shares of convertible preferred stock, par value $.10
per share, of Grace (the "New Sealed Air Preferred Stock," together with the
New Sealed Air Common Stock, the "New Sealed Air Shares") proposed to be
issued in connection with the recapitalization of Grace (the
"Recapitalization") upon the terms and subject to the conditions of the Form
of Distribution Agreement (the "Distribution Agreement"), to be entered into
prior to the effective time of the Merger (as defined herein), filed as
Exhibit 2.2 to the Registration Statement, by and among Grace, Packco
Acquisition Corp., a Delaware corporation and a wholly owned subsidiary of
Grace ("Packco") and Sealed Air Corporation, a Delaware corporation ("Sealed
Air"); and (2) the New Sealed Air Common Stock proposed to be issued in the
merger (the "Merger") of Packco with and into Sealed Air, upon the terms and
subject to the conditions of the Agreement and Plan of Merger (the "Merger
Agreement"), dated as of August 14, 1997, filed as Exhibit 2.1  to the
Registration Statement, by and among Grace, Sealed Air and Packco.

               In connection with this opinion, we have examined the Amended
and Restated Certificate of Incorporation and Amended and Restated By-Laws of
Grace in the respective forms contemplated to be in effect at the time that
the New Sealed Air Shares are issued, the Registration Statement and the
exhibits thereto, and we have examined originals or copies, certified or
otherwise identified to our satisfaction, of such corporate records,
agreements, certificates of public officials and of officers of Grace and
other instruments, and such matters of law and fact as we have deemed
necessary to render the opinion contained herein.

               In giving the opinion contained herein, we have with your
approval relied upon representations of officers of Grace and certificates of
public officials with respect to the accuracy of the material factual matters
addressed by such representations and certificates.  We have, with your
approval, assumed the genuineness of all signatures or instruments submitted
to us, and the conformity of certified copies submitted to us with the
original documents to which such certified copies relate.

               We are members of the Bar of the State of New York and we
express no opinion as to the laws of any jurisdiction other than the federal
laws of the United States, the General Corporation Law of the State of
Delaware and the laws of the State of New York.

               Based upon and subject to the foregoing, and assuming (i) the
certificates representing the New Sealed Air Shares will be manually signed by
one of the authorized officers of First Chicago Trust Company of New York, as
transfer agent and registrar for the New Sealed Air Shares (the "Transfer
Agent and Registrar"), and registered by the Transfer Agent and Registrar,
(ii) the consummation of the Merger and Recapitalization as contemplated by
the Merger Agreement and Distribution Agreement, respectively, and (iii) that
the shares of Sealed Air common stock to be exchanged for New Sealed Air
Common Stock in the Merger and that the shares of Grace common stock to be
exchanged for New Sealed Air Shares in the Recapitalization have been validly
issued, fully paid and non-assessable, we are of the opinion that, upon the
amendment of the Amended and Restated Certificate of Incorporation of Grace to
authorize a sufficient number of shares of the common and preferred stock of
Grace, and upon the Merger having been approved by the stockholders of Grace
and becoming effective pursuant to the General Corporation Law of the State of
Delaware, all as described in the Registration Statement and any amendments
thereto, the New Sealed Air Shares will be duly authorized and, when issued in
the manner described in the Registration Statement and any amendments thereto,
will be validly issued, fully paid, and non-assessable.

               We hereby consent (i) to the filing of this opinion with the
Commission as an exhibit to the Registration Statement and (ii) to the
statement made in reference to our firm under the caption "LEGAL MATTERS" in
the Joint Proxy Statement/Prospectus which is made a part of the Registration
Statement.  We do not hereby admit by giving this consent that we are in the
category of persons whose consent is required under Section 7 of the 1933 Act.

Very truly yours,

/s/ Wachtell, Lipton, Rosen & Katz
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    Wachtell, Lipton, Rosen & Katz