Exhibit 5

                        [MKB LETTERHEAD]

                                                   (610) 341-1070


                                               September 30, 2002



Securities and Exchange Commission
Division of Corporation Finance
450 Fifth Street, N.W.
Washington, D.C. 20549

          Re:  Airgas, Inc. Registration Statement on
               Form S-8/1997 Stock Option Plan, As Amended

Ladies and Gentlemen:

      We have acted as counsel to Airgas, Inc. (the "Company"), a
Delaware  corporation,  in connection with  the  preparation  and
filing of a Registration Statement on Form S-8 (the "Registration
Statement").   Capitalized  terms not  otherwise  defined  herein
shall  have  the  meanings ascribed to them in  the  Registration
Statement.

      The Registration Statement covers (i) 3,200,000 shares (the
"Shares")  of the Company's Common Stock which may be  issued  by
the  Company  upon exercise of options granted or  available  for
grant under the Company's 1997 Stock Option Plan, as amended (the
"Plan").  We have examined the Registration Statement,  including
the exhibits thereto, the Company's Certificate of Incorporation,
as  amended,  the  Company's Bylaws, as  amended,  the  Plan  and
related  minutes of actions taken by the Board of  Directors  and
stockholders  of  the Company.  In the foregoing examination,  we
have  assumed the genuineness of all signatures, the authenticity
of   all   documents  submitted  to  us  as  originals  and   the
authenticity  of  all documents submitted  to  us  as  copies  of
originals.

      Based  upon the foregoing, we are of the opinion  that  the
Shares, when issued and paid for in accordance with the terms of,
and upon exercise of the options granted under, the Plan, will be
validly issued, fully paid and non-assessable.


Securities and Exchange Commission
Division of Corporation Finance
September 30, 2002
Page 2


     We hereby consent to the filing of this opinion as Exhibit 5
to the Registration Statement.  In giving this consent, we do not
hereby  admit  that we come within the category of persons  whose
consent  is  required under Section 7 of the  Securities  Act  of
1933, as amended, or the rules and regulations thereunder.

                         Sincerely,

                         McCAUSLAND, KEEN & BUCKMAN



                         By: /s/ Nancy D. Weisberg
                         ---------------------------------
                         Nancy D. Weisberg, Vice President

NDW/jme