<PAGE>   1
                                                                     EXHIBIT 4.1

                               AMENDMENT  NO.  8


      THIS AMENDMENT NO. 8 (this "Amendment"), dated as of September 9, 1996,
among United States Can Company, a Delaware corporation (the "Borrower"), the
various financial institutions that are or may become parties to the Credit
Agreement described hereinbelow (individually, a "Lender" and collectively, the
"Lenders") and Bank of America Illinois, an Illinois banking corporation, as
agent for the Lenders (in such capacity, the "Agent"), is made pursuant to
Section 9.1 of that certain Credit Agreement, dated as of April 29, 1994 (as
amended or modified and in effect on the date hereof, the "Existing Credit
Agreement" and, as amended or otherwise modified in this Amendment, the
"Amended Credit Agreement"; capitalized terms used but not defined herein
having the same respective meanings as in the Amended Credit Agreement), among
the Borrower, the Lenders and the Agent.

                                  WITNESSETH:

      WHEREAS, the Borrower has requested that the Lenders amend the Existing
Credit Agreement in the manner hereinafter appearing; and, subject to the terms
and conditions set forth herein, the Lenders have agreed to so amend the
Existing Credit Agreement;

      NOW, THEREFORE, for good and valuable consideration, the receipt and
sufficiency of which is hereby acknowledged, the parties hereto, intending to
be legally bound, hereby agree as follows:

                            ARTICLE 1. - AMENDMENTS

      1.1. Section 2.8.1(e) of the Existing Credit Agreement is hereby amended
by inserting the phrase "the Parent," immediately before the phrase "the
Borrower" in the first line thereof.

      1.2. Section 2.22(c)(iv) of the Existing Credit Agreement is hereby
amended by deleting the last word "and" therefrom.

      1.3. Section 2.22(c)(v) of the Existing Credit Agreement is hereby
amended by deleting the final period and substituting the phrase "; and" in
lieu thereof.

      1.4. The following new clause (vi) is hereby added to Section 2.22(c) of
the Existing Credit Agreement:


      (vi) (A)  guaranties by any or all of the European Subsidiaries of the
           Obligations as the Majority Lenders may request in their sole
           discretion, (B) such documents as the Majority Lenders may request
           in their sole discretion to evidence and perfect security interests
           in the stock and assets of any or all of the European Subsidiaries 
           or stock of Subsidiaries other than the European Subsidiaries 
           and assets having a substantially equivalent fair market 
           value to the stock and assets of such European





<PAGE>   2

           Subsidiaries (the "European Collateral Documents"), and (C) the
           Borrower and each applicable Subsidiary have taken all other steps
           reasonably requested to grant to the Agent, for the benefit of the
           Secured Parties, a first priority Lien in the collateral described
           in the European Collateral Documents, subject to no Liens whatsoever
           except for Liens permitted under the European Collateral Documents.

      1.5. Section 4.4(c) of the Existing Credit Agreement is hereby amended by
inserting the following phrase immediately before the final period thereof:

      "; provided that none of the foregoing in this clause (c) shall apply
      with respect to the Acquisition of any Acquisition Target that is a
      European Acquisition Target if the Borrower has made or caused to be made
      the necessary filings (which shall not be withdrawn) with appropriate
      governmental authorities within forty-five (45) days of the consummation
      of such Acquisition such that the assets of such European Acquisition
      Target will be owned (either directly or indirectly) by U.S.C. Europe
      N.V."

      1.6. Section 6.2(b)(i) of the Existing Credit Agreement is hereby amended
in its entirety to read as follows:

           (i)   Investments by the Borrower in any of its Subsidiaries (A)
      owned on the date hereof, (B) acquired as permitted by Section 6.2(a) or
      (C) that are European Subsidiaries, or by any such Subsidiary in any of
      its Subsidiaries, in the form of contributions to capital or loans or
      advances; provided that any Investments in the European Subsidiaries or
      any Subsidiaries thereof shall either (X) be in the form of equity
      contributions permitted by Section 6.2(n) or (Y) if not included in
      clause (X), not exceed $10,000,000 in the aggregate at any one time
      outstanding; and provided further, that no Investment permitted by this
      paragraph shall be made at any time that a Default or Event of Default
      shall have occurred and is continuing or would result therefrom;

      1.7. Section 6.2(c)(v) of the Existing Credit Agreement is hereby amended
in its entirety to read as follows:

           (v)   the Borrower may refinance the Subordinated Notes with the
      proceeds of any Approved Parent Debt; and

      1.8. Section 6.2(c) of the Existing Credit Agreement is hereby amended by
inserting the following clause (vi) immediately before the phrase "provided
that no Default" in the third to last line thereof:

           (vi)  the Borrower may declare and simultaneously make Debt Service
      Dividends;

      1.9. Section 6.2(f) of the Existing Credit Agreement is hereby amended in
its entirety to read as follows:





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<PAGE>   3


           (f)   Guaranties.  The Borrower shall not, and shall not permit any
      of its Subsidiaries to, create or become or be liable, whether directly
      or indirectly, with respect to any Guaranty, except that the Borrower may
      incur unsecured Guaranties (I) of the obligations of the Parent under any
      Approved Parent Debt, (II) for the benefit of any supplier or vendor to
      the European Subsidiaries to secure obligations incurred in the ordinary
      course of business by the European Subsidiaries, and (III) unless
      otherwise permitted in clauses (I) or (II), (i) for the benefit of the
      Borrower or any Subsidiary if the primary obligation is permitted by this
      Agreement, (ii) for the benefit of the Parent or any wholly-owned
      subsidiary of the Parent, and (iii) for the benefit of any supplier or
      vendor to the Borrower or its Subsidiaries to secure obligations incurred
      in the ordinary course of business by the Borrower or its Subsidiaries
      (provided that the aggregate amount of such Guaranties described in
      clause (iii) outstanding at any time shall not exceed $5,000,000);
      provided that (x) each Guaranty permitted under clauses (I) or (III) is
      limited in amount to a stated maximum dollar liability, (y) each Guaranty
      permitted under clause (II) is limited in amount to the aggregate
      purchase price of goods purchased by the applicable European Subsidiary
      from such supplier or vendor, and (z) after the incurrence of each such
      Guaranty, there would exist no Default or Event of Default.
      Notwithstanding anything in the foregoing sentence to the contrary, the
      Guaranties permitted under clauses (III)(i), (ii) and (iii) above shall
      in all cases be limited in amount to a stated maximum dollar liability of
      $10,000,000 in the aggregate for the Borrower and the Subsidiaries at any
      one time.

      1.10.      Section 6.2(i) of the Existing Credit Agreement is hereby
amended by deleting the proviso immediately after the words "twelve consecutive
months" in the seventh line thereof and substituting the following phrase in
lieu thereof:

      "; provided that the Borrower may refinance the Subordinated Notes with
      the proceeds of any Approved Parent Debt"

      1.11.      Section 6.2(n) of the Existing Credit Agreement is hereby
amended by inserting the following phrase immediately before the final period
thereto:

      "; provided that the Borrower may make equity contributions of (i) the
      assets or stock of an Acquisition Target, (ii) the proceeds of an
      Acquisition Loan for the purpose of making an Acquisition, (iii) the
      European Subsidiaries to U.S.C. Europe N.V., and (iv) $1,200,000 to
      U.S.C. France Holding, S.A.S., provided that such amount is dividended to
      the Borrower within sixty (60) days of such equity contribution.

      1.12.      Section 6.2 of the Existing Credit Agreement is hereby amended
by adding the following clause (r) thereto:

           (r)   U.S.C. Europe N.V.  So long as any Obligations with respect to
      Acquisition Loans shall remain outstanding, the Borrower shall not permit
      its Subsidiary, U.S.C. Europe N.V., to (i) own any assets other than the
      capital stock of (A) European Subsidiaries or (B) upon prior written
      notice to the Agent, any other Subsidiary incorporated under the laws of
      a jurisdiction other than the United States of America or any political
      subdivision thereof, (ii) make any expenditures other than such minimal
      expenditures necessary to maintain its separate corporate existence and
      good standing in the Netherlands Antilles, (iii) create, incur,





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<PAGE>   4

      assume or otherwise become liable with respect to any Debt, (iv) have any
      employees or engage in any trade or business, (v) merge or consolidate
      with any other Person, (vi) sell or otherwise transfer any of its assets
      or (vii) create, incur, assume or permit to exist any Lien on any of its
      assets.

      1.13.      The definition of "Current Ratio" in Schedule I of the
Existing Credit Agreement is hereby amended by adding the following sentence to
the end thereof:

      "Current Ratio", when used with respect to the Borrower, shall include
      any current liabilities of the Parent with respect to any Approved Parent
      Debt to the extent that the proceeds of such Approved Parent Debt are not
      irrevocably deposited in a trust or similar escrow account until the
      Subordinated Notes are callable on January 15, 1997.

      1.14.      The definition of "Net Securities Proceeds" in Schedule I of
the Existing Credit Agreement is hereby amended in its entirety to read as
follows:

           "Net Securities Proceeds" means the net cash proceeds (i.e., gross
      cash proceeds minus reasonable and customary underwriting commissions,
      legal, accounting or other usual professional fees and taxes) received by
      the Parent, the Borrower or any Subsidiary from any sale or issuance of
      any debt or equity securities; provided that "Net Securities Proceeds"
      shall not include the proceeds of any Approved Parent Debt applied to the
      prepayment of the Subordinated Notes (or irrevocably deposited in a trust
      or similar escrow account for such purpose until the Subordinated Notes
      are callable on January 15, 1997) and any related prepayment premiums
      required by the terms of the Subordinated Notes.

      1.15.      The definition of "Net Worth" in Schedule I of the Existing
Credit Agreement is hereby amended by inserting the following phrase
immediately before the final period thereof:

      "; provided, that for the purposes of calculating the consolidated Net
      Worth of the Borrower under Section 6.3(f), Net Worth shall not include
      any equity contributions made by the Parent to the Borrower which
      constitute proceeds of any Approved Parent Debt"

      1.16.      The definition of "Required Debt Amortization" in Schedule I
of the Existing Credit Agreement is hereby amended by inserting the following
phrase immediately before the final period thereof:

      "; provided that for the purposes of this definition, any payments of
      Debt Service Dividends shall be treated as if the Borrower had incurred
      the Approved Parent Debt and was making payments in an amount equal to
      such Debt Service Dividends thereon"

      1.17.      The definition of "Subordinated Debt" in Schedule I of the
Existing Credit Agreement is hereby amended in its entirety to read as follows:





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<PAGE>   5


           "Subordinated Debt" means both (i) any Guaranties by the Borrower of
      the obligations of the Parent under any Approved Parent Debt and (ii)
      unsecured indebtedness of the Borrower, which in each case is
      subordinated in right of payment to the Obligations and which contains
      terms and conditions which are acceptable to the Agent and the Majority
      Lenders in their reasonable discretion (including terms and conditions
      with respect to amounts, maturities, covenants, defaults, remedies and
      subordination); such definition to include the Subordinated Notes.

      1.18.      The last sentence of the definition of "Total Funded Debt" in
Schedule I of the Existing Credit Agreement is hereby amended by adding the
following phrase immediately before the final period thereof:

      "; provided that such Total Funded Debt shall not include any Guaranties
      by the Borrower of the obligations of the Parent under any Approved
      Parent Debt to the extent that the proceeds of such Approved Parent Debt
      are irrevocably deposited in a trust or similar escrow account until the
      Subordinated Notes are callable on January 15, 1997"

      1.19.      Schedule I of the Existing Credit Agreement is hereby amended
by adding the following new definitions in the appropriate alphabetical order:

           "Approved Parent Debt" means any Debt issued by the Parent, the
      proceeds of which are applied to (a) the prepayment of the Subordinated
      Notes (or irrevocably deposited in a trust or similar escrow account for
      such purpose until the Subordinated Notes are callable on January 15,
      1997), (b) any related prepayment premiums required by the terms of the
      Subordinated Notes or (c) the prepayment of first, the Acquisition Loans,
      and second, the Revolving Loans; provided that the terms and conditions
      of any such Approved Parent Debt are as follows: (v) the principal
      amortization is not shorter, (w) the interest rate is not greater, (x)
      the covenants are not more restrictive, (y) the subordination provisions
      are not less protective of senior debt of the Borrower and (z) the terms
      and conditions are otherwise no less favorable to the Parent and the
      Borrower than the terms and conditions of the Subordinated Notes.

           "Debt Service Dividends" means cash dividends declared and made by
      the Borrower to the Parent in such amounts and to the extent necessary to
      allow the Parent to make any regularly scheduled payment of principal or
      interest in respect of any Approved Parent Debt if and to the extent that
      such payment is not prohibited at such time by the subordination
      provisions or other applicable terms of such Approved Parent Debt or any
      instrument governing such Approved Parent Debt.

           "European Acquisition Target" means an Acquisition Target listed on
      Schedule V.

           "European Collateral Documents" has the meaning specified in Section
      2.22(c)(vi).

           "European Subsidiary" means a Subsidiary of the Borrower listed on
      Schedule VI.





                                     -5-
<PAGE>   6

      1.20.      The Existing Credit Agreement is hereby amended by adding to
the end thereof a new Schedule V in the form of Schedule V hereto.

      1.21.      The Existing Credit Agreement is hereby amended by adding to
the end thereof a new Schedule VI in the form of Schedule VI hereto.

                            ARTICLE 2. - CONDITIONS

         2.1.    This Amendment shall become effective as of the date hereof on
the date (the "Amendment Effective Date") that the Agent shall have received
each of the following, in form and substance satisfactory to it:

                 (a)      counterparts hereof executed by the Borrower and the
         Lenders;

                 (b)      a certificate, dated as of the Amendment Effective
         Date, of the Secretary or Assistant Secretary of the Borrower as to
         resolutions of its Board of Directors then in full force and effect
         authorizing the execution and delivery of this Amendment and the
         incumbency and signatures of its officers signing this Amendment;

                 (c)      a certificate, dated as of the Amendment Effective
         Date, of an authorized officer of the Borrower as to (i) no Default or
         Event of Default as of the Amendment Effective Date after giving
         effect to this Amendment, (ii) the correctness of the representations
         and warranties contained in the Loan Documents in all material
         respects as of the Amendment Effective Date after giving effect to
         this Amendment, (iii) no amendments or other modifications to the
         Borrower's Certificate of Incorporation and By-Laws having occurred
         since the date that the certified copies of such documents were
         delivered by the Borrower pursuant to Sections 4.1(b) and 4.1(c) of
         the Existing Credit Agreement, respectively, and (iv) the satisfaction
         of each of the conditions precedent contained in this Article II;

                 (d)      evidence that the Borrower shall have pledged
         sixty-five percent (65%) of the outstanding capital stock of U.S.C.
         Europe N.V. to the Agent, for the benefit of the Secured Parties,
         pursuant to an amendment to the Pledge Agreement; and

                 (e)      an opinion of counsel for the Borrower as to this
         Amendment and the transactions contemplated hereby, in form and
         substance satisfactory to the Agent.

         2.2.  The Agent agrees to notify the Borrower and the Lenders of such
Amendment Effective Date promptly after such Amendment Effective Date occurs.

                              ARTICLE 3. - GENERAL

         3.1.    To induce the Agent and the Lenders to enter into this
Amendment, the Borrower warrants to the Agent and the Lenders that: (a) the
warranties contained in the Loan Documents, as amended by the Amendment, are





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<PAGE>   7

true and correct in all material respects as of the date hereof with the same
effect as though made on the date hereof; (b) after giving effect to this
Amendment, no Event of Default or Default exists; (c) this Amendment has been
duly authorized by all necessary corporate proceedings and duly executed and
delivered by the Borrower, and the Amended Credit Agreement and each of the
other Loan Documents are the legal, valid and binding obligations of the
applicable Loan Party, enforceable against such Loan Party in accordance with
their respective terms, except as enforceability may be limited by bankruptcy,
insolvency or other similar laws of general application affecting the
enforcement of creditors' rights or by general principles of equity; (d) no
consent, approval, authorization, order, registration or qualification with any
Governmental Authority or securities exchange is required for, and in the
absence of which would adversely affect, the legal and valid execution and
delivery or performance by the Borrower of this Amendment or the performance by
the Borrower of the Amended Credit Agreement or any other Loan Document to
which it is a party; and (e) the Agent has a first priority lien in the
Collateral subject to no other liens, claims or encumbrances whatsoever other
than the "Permitted Liens" (as defined in the Additional Security Agreement).

         3.2.    This Amendment may be executed in any number of counterparts
and by the different parties on separate counterparts and each such counterpart
shall be deemed to be an original, but all such counterparts shall together
constitute but one and the same Amendment.

         3.3.    Except as specifically provided above, the Existing Credit
Agreement and the other Loan Documents shall remain in full force and effect
and are hereby ratified and confirmed in all respects.  The execution,
delivery, and effectiveness of this Amendment shall not, except as expressly
provided herein, operate as a waiver of any right, power, or remedy of the
Agent or any Lender under the Existing Credit Agreement or any of the other
Loan Documents, nor constitute a waiver or modification of any provision of any
of the other Loan Documents, and the Obligations shall continue to be secured
in all respects by the Collateral.

         3.4.    On and after the Amendment Effective Date, each reference in
the Existing Credit Agreement and related documents to "Credit Agreement,"
"this Agreement" or words of like import, shall, unless the context otherwise
requires, be deemed to refer to the Amended Credit Agreement.

         3.5.    The Borrower agrees to pay on demand all reasonable costs and
expenses incurred at any time by the Agent (including the reasonable attorney
fees and expenses for the Agent, including the allocated cost of internal
counsel) in connection with the preparation, negotiation, execution and
administration of this Amendment and all other instruments or documents
provided for herein or delivered or to be delivered hereunder or in connection
herewith.

         3.6.    This Amendment shall be binding upon the Borrower, the Agent,
the Lenders and their respective successors and assigns, and shall inure to the
benefit of the Borrower, the Agent, the Lenders and their respective successors
and assigns as provided in the Amended Credit Agreement.


                               *   *   *   *   *





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<PAGE>   8

     IN WITNESS WHEREOF, the parties hereto have caused this Amendment to be
executed by their respective officers thereunto duly authorized as of the day
and year first above written.


                              UNITED STATES CAN COMPANY
                             
                             
                             
                              By:         /s/ Peter J. Andres                 
                                        --------------------------------------
                              Name:       Peter J. Andres                    
                                        -------------------------------------
                              Title:      Vice President                      
                                        --------------------------------------
                             
                             
                              BANK OF AMERICA ILLINOIS, as Agent
                             
                             
                             
                              By:         /s/ David L. Graham               
                                        ------------------------------------
                              Name:       David L. Graham                   
                                        ------------------------------------
                              Title:      Vice President                     
                                        -------------------------------------
                             
                             
                              BANK OF AMERICA ILLINOIS, individually
                             
                             
                             
                              By:         /s/ Tracy J. Alfery                
                                        -------------------------------------
                              Name:       Tracy J. Alfery                    
                                        -------------------------------------
                              Title:      Vice President                     
                                        -------------------------------------
                             
                             
                              THE FIRST NATIONAL BANK OF CHICAGO
                             
                             
                             
                              By:         /s/ Cory M. Helfand               
                                        ------------------------------------
                              Name:       Cory M. Helfand                   
                                        ------------------------------------
                              Title:      Vice President                     
                                        -------------------------------------
                             




<PAGE>   9

                              HARRIS TRUST AND SAVINGS BANK
                              
                              
                              
                              By:         /s/ Ronald L. Dellartino            
                                        --------------------------------------
                              Name:       Ronald L. Dellartino               
                                        -------------------------------------
                              Title:      Vice President                     
                                        -------------------------------------
                              
                              
                              FLEET NATIONAL BANK
                              
                              
                              
                              By:         /s/ Stephen P. Kanarian           
                                        ------------------------------------
                              Name:       Stephen P. Kanarian               
                                        ------------------------------------
                              Title:      V.P.                                
                                        --------------------------------------
                              
                              
                              BANK OF SCOTLAND
                              
                              
                              
                              By:         /s/ Catherine M. Oniffrey          
                                        -------------------------------------
                              Name:       Catherine M. Oniffrey             
                                        ------------------------------------
                              Title:      Vice President                     
                                        -------------------------------------
                              
                              
                              THE NORTHERN TRUST COMPANY
                              
                              
                              
                              By:         /s/ Arthur J. Fogel                 
                                        --------------------------------------
                              Name:       Arthur J. Fogel                    
                                        -------------------------------------
                              Title:      Vice President                     
                                        -------------------------------------
                              




<PAGE>   10

                              SOCIETE GENERALE
                              
                              
                              
                              By:         /s/ Joseph A. Philbin               
                                        --------------------------------------
                              Name:       Joseph A. Philbin                  
                                        -------------------------------------
                              Title:      Vice President                      
                                        --------------------------------------
                              




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<PAGE>   11

                                   SCHEDULE V

                          EUROPEAN ACQUISITION TARGETS


Name                                                       Jurisdiction
----                                                       ------------
                                           
CarnaudMetalbox Aerosols S.A.                                France
                                           
CMB Aerosoldosen Deutschland GmbH                            Germany
                                           
CMB Aerosoles S.A.                                            Spain
                                           
                                           
                                           
                                           

<PAGE>   12

                                  SCHEDULE VI

                             EUROPEAN SUBSIDIARIES


                                                   
Name                                                     Jurisdiction
----                                                     ------------
                                                   
U.S.C. Europe N.V.                                  Netherlands Antilles
                                                   
Thuvine Duiven B.V.                                      Netherlands
                                                   
U.S.C. Holding U.K. Ltd.                                   England
                                                   
U.K. Can Ltd.                                              England
                                                   
U.S.C. Europe U.K. Ltd.                                    England
                                                   
U.S.C. Europe Italia, S.r.l.                                Italy
                                                   
U.S.C. France Holding, S.A.S.                              France
                                                   
CarnaudMetalbox Aerosols S.A.                      
(to be known as U.S.C. Aerosols France, S.A.S.)            France
                                                   
Can Beteiligungs GmbH                                      Germany
                                                   
Can Verwaltungs GmbH                                       Germany
                                                   
U.S.C. Aerosoldosen Deutschland GmbH & Co. KG              Germany
                                                   
U.S. Can Espana Holding SCpA                                Spain
                                                   
CMB Aerosoles S.A.                                 
(to be known as U.S.C. Europe Espana SCpA)                  Spain