EXECUTION COPY

                                 AMENDMENT NO. 1

                  AMENDMENT NO. 1 dated as of November 14, 1997, between:

                  NUCO2 INC., a corporation  duly organized and validly existing
         under the laws of the State of Florida (the "Company") ;

                  each of the  Subsidiaries  of the Company  appearing under the
         caption  "SUBSIDIARY  GUARANTORS" on the signature pages hereto (each a
         "SUBSIDIARY GUARANTOR" and, collectively,  the "SUBSIDIARY GUARANTORS";
         and, together with the Company, the "Obligors"); and

                  each of the Investors,  including the Additional  Investor (as
         defined  below),   appearing  under  the  caption  "INVESTORS"  on  the
         signature  pages hereto (each,  an "INVESTOR",  and  collectively,  the
         "INVESTORS").

                  The  Obligors  and the  Investors  (other than the  Additional
Investor) are party to a Senior Subordinated Note Purchase Agreement dated as of
October 31, 1997 (as heretofore  modified and  supplemented and in effect on the
date  hereof,  the "NOTE  PURCHASE  AGREEMENT"),  pursuant  to which the Company
issued on  October  31,  1997 its 12% Senior  Subordinated  Notes due 2004 in an
aggregate  principal  amount of $25,000,000 to such Investors.  PaineWebber High
Income Fund, a series of PaineWebber  Managed Investments Trust (the "ADDITIONAL
INVESTOR")  desires to become an Investor  party to the Note Purchase  Agreement
and to  purchase  from the  Company,  and the  Company  desires  to issue to the
Additional Investor,  an additional 12% Senior Subordinated Note due 2004 in the
principal  amount of  $5,000,000  having the same terms as the Notes  heretofore
issued by the Company  under the Note Purchase  Agreement.  The Obligors and the
Investors  (including the  Additional  Investor) wish to amend the Note Purchase
Agreement  to add the  Additional  Investor  as an  Investor  thereunder  and to
provide  for  the  issuance  of  such   additional   Notes  and  to  make  other
modifications to the Note Purchase  Agreement.  Accordingly,  the parties hereto
hereby agree as follows:

                  Section 1.  DEFINITIONS.  Except as otherwise  defined in this
Amendment No. 1, terms defined in the Note Purchase Agreement are used herein as
defined therein.

                  Section  2.  AMENDMENTS.  Subject to the  satisfaction  of the
conditions  precedent specified in Section 4 below, but effective as of the date
hereof, the Note Purchase Agreement shall be amended as follows:



                                 AMENDMENT NO. 1

<PAGE>
                                 AMENDMENT NO. 1

                  A.  References  in  the  Note  Purchase   Agreement  to  "this
Agreement" (and indirect references such as "hereunder",  "hereby", "herein" and
"hereof")  shall be deemed to be references  to the Note  Purchase  Agreement as
amended hereby.

                  B. A new Section 2.06 is added to the Note Purchase  Agreement
to read as follows:

                           "SECTION 2.06 ISSUANCE OF ADDITIONAL NOTE. Subject to
         and  upon  the  terms  and  conditions  set  forth  in the  immediately
         succeeding  sentence,   PaineWebber  High  Income  Fund,  a  series  of
         PaineWebber  Managed  Investments  Trust  (the  "ADDITIONAL  INVESTOR")
         agrees to purchase from the Company, and the Company agrees to issue to
         the  Additional  Investor,   its  12%  Senior  Subordinated  Note  (the
         "ADDITIONAL  NOTE"),  which  Additional  Note (i)  shall be  issued  on
         November 14, 1997 (or such later date as the Company and the Additional
         Investor shall mutually  agree,  but not later than November 21, 1997),
         (ii) shall be in a principal  amount of $5,000,000 and purchased at par
         by the Additional  Investor and (iii) shall otherwise be in the form of
         Exhibit  A.  The  Additional  Note  shall  constitute  a Note,  and the
         Additional  Investor  shall be an  Investor,  for all  purposes of this
         Agreement.  The  issuance  of the  Additional  Note  to the  Additional
         Investor is subject,  at the time of purchase,  to the  satisfaction of
         the following  conditions:  (i) receipt by the Additional Investor of a
         certificate of a senior officer of the Company,  dated the date of such
         purchase, to the effect, both immediately prior to the purchase of such
         Additional  Note and also after giving effect  thereto and the intended
         use  thereof,  set forth in clauses (a) and (b) of Section  5.02;  (ii)
         receipt  by the  Additional  Investor  of  the  Additional  Note,  duly
         executed  and  completed  for the  Additional  Investor;  and (iii) the
         execution  and  delivery  of an  amendment  to  the  Warrant  Agreement
         satisfactory to the Additional Investor providing for the issuance of a
         Warrant to the Additional  Investor (or any Affiliate  thereof) for the
         purchase of 109,290  Stock Units (as defined in the Warrant  Agreement)
         and making certain other  modifications  thereto as mutually  agreed by
         the Company and the Investors (including the Additional Investor)."

                  C. Section  3.01(a) of the Note Purchase  Agreement is amended
to insert a new sentence at the end thereof to read as follows:

         "Notwithstanding  anything  in  this  Agreement  to  the  contrary,  no
         prepayment  may be made under this Section 3.01 if after giving  effect
         to such prepayment the aggregate principal

                                 AMENDMENT NO. 1

                                       -2-

<PAGE>
         amount of the Notes then outstanding would be less than
         $15,000,000, unless all of the Notes are prepaid in full."

                  D. A new Section 8.13 is added to the Note Purchase  Agreement
to read as follows:

                           "SECTION 8.13 CREDIT RATING.  Within the period of 18
         months of the Closing Date, the Company will use all reasonable efforts
         to obtain a credit rating from S&P,  Moody's or Duff & Phelps,  Inc. or
         any other nationally  recognized credit rating agency acceptable to the
         Required Investors,  PROVIDED that the failure of the Company to obtain
         such  rating  within  such  period  shall  not give  rise to a  Default
         hereunder or entitle the  Investors to exercise any remedy  against the
         Company hereunder or otherwise."

                  Section 3.                REPRESENTATIONS AND WARRANTIES.

                  (a) The Company  represents and warrants to the Investors that
the  representations and warranties set forth in Article VI of the Note Purchase
Agreement  are true and  complete on the date hereof as if made on and as of the
date hereof and as if each reference in said Article VI to "this  Agreement" (or
words of similar import)  referred to the Note Purchase  Agreement as amended by
this Amendment No. 1.

                  (b) The Additional Investor represents to the Company that the
representations  set forth in Article IV of the Note Purchase Agreement are true
and complete with respect to the Additional  Investor on the date of purchase of
the  Additional  Note as if made on and as of such date and as if each reference
in said Article IV to "this  Agreement" (or words of similar import) referred to
the Note Purchase Agreement as amended by this Amendment No. 1.

                  Section 4.  CONDITIONS  PRECEDENT.  As  provided  in Section 2
above, the amendments to the Note Purchase Agreement set forth in said Section 2
shall become effective,  as of the date hereof,  upon the execution and delivery
of one or more  counterparts  of this  Amendment  No.  1 by each of the  parties
hereto.

                  Section 5. MISCELLANEOUS.  Except as herein provided, the Note
Purchase  Agreement  shall remain  unchanged and in full force and effect.  This
Amendment  No. 1 may be  executed  in any number of  counterparts,  all of which
taken together shall  constitute one and the same amendatory  instrument and any
of the  parties  hereto may  execute  this  Amendment  No. 1 by signing any such
counterpart.  This  Amendment  No. 1 shall be  governed  by,  and  construed  in
accordance with, the law of the State of New York.

                                 AMENDMENT NO. 1

                                       -3-

<PAGE>
                  IN WITNESS  WHEREOF,  the  parties  hereto  have  caused  this
Amendment  No. 1 to be duly  executed and delivered as of the day and year first
above written.



                                        NUCO2 INC.


                                        By /S/ JOANN SABATINO
                                           ---------------------
                                           Title: CFO

                                        SUBSIDIARY GUARANTORS

                                        NUCO2 ACQUISITION CORP.


                                        By /S/ JOANN SABATINO
                                           ---------------------
                                           Title: Secretary


                                        KOCH COMPRESSED GASES, INC.


                                        By /S/ JOANN SABATINO
                                           ---------------------
                                           Title: Secretary



                                 AMENDMENT NO. 1

                                       -4-

<PAGE>
                                        INVESTORS

                                        CHASE EQUITY ASSOCIATES L.P..

                                        By Chase Capital Partners,
                                           its general partner


                                        By/S/ RICHARD WATERS
                                          --------------------
                                          Title: General Partner

                                        DK ACQUISITION PARTNERS, L.P.

                                        By M.H. Davidson & Co.,
                                           its general partner

                                        By/S/ THOMAS L. KEMPER
                                          ----------------------
                                          Title: General Partner

                                        EMPIRE INSURANCE COMPANY, as
                                        executed on their behalf by their
                                        Investment Manager, Cohanzick
                                        Management , LLC


                                        By/S/ DAVID SHERMAN
                                          -------------------
                                          Title: President


                                        ORIX USA CORPORATION


                                        By/S/ FRANKLIN CLARKE
                                          ---------------------
                                          Title: Vice President



                                 AMENDMENT NO. 1

                                       -5-

<PAGE>



AMOUNT OF ADDITIONAL NOTE                 PAINEWEBBER HIGH INCOME FUND,
                                               a series of PaineWebber
$5,000,000                                     Managed Investments Trust


                                          By/S/ PAUL SCHUBERT
                                            -------------------------
                                            Title:  Paul Schubert
                                                    Vice President and
                                                    Treasurer

                                          Address for Notices:

                                          PAINEWEBBER HIGH INCOME FUND,
                                               series of PaineWebber Managed
                                               Investments Trust
                                          c/o Mitchell Hutchins Asset
                                                Management Inc.
                                          1285 Avenue of the Americas
                                          New York, New York 10019
                                          Attention: Ms. Jenny A. Hutchinson

                                          Fax No.: (212) 586-8982
                                          Telephone No.: (212) 713-6047





                                 AMENDMENT NO. 1

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