<PAGE>   1

                                  EXHIBIT 10.4
<PAGE>   2

                                 FIRST AMENDMENT

                                       to

                                 LOAN AGREEMENT

      This FIRST AMENDMENT (this "Amendment"), dated as of 15 August 1998 by and
among (a) GfE Gesellschaft fur Elektrometallurgie mit beschrankter Haftung, a
German corporation having its principal place of business at Hofener Stra(beta)e
45, 90431 Nurnberg ("GfE Holding Company"), GfE Umwelttechnik GmbH, a German
corporation having its principal place of business at Hofener Stra(beta)e 45,
90431 Nurnberg ("GfE UT") GfE Gie(beta)erei- und Stahlwerksbedarf GmbH, a German
corporation having its principal place of business at KreuzStra(beta)e 34, 40210
Dusseldorf ("GfE G&S"), GfE Metalle und Materialien GmbH, a German corporation
having its principal place of business at Hofener Stra(beta)e 45, 90431 Nurnberg
("GfE M&M"), KERAMED Medizintechnik GmbH, a German corporation having its
principal place of business at An den Trillers Buschen 2, 07646
Morsdorf/Thuringen ("KERAMED"), and collectively with GfE Holding Company, GfE
UT, GfE G&S and GfE M&M, the ("Borrowers"), and (b) BankBoston, N.A., London
Branch (the "Bank") is an amendment of the Loan Agreement dated 22 July 1998 by
and among the Borrowers and the Bank (as so amended, the "Loan Agreement").

      WHEREAS, the Borrowers have requested, and the Bank has agreed, subject to
the terms and conditions set forth herein, to make certain amendments to the
Loan Agreement as specifically set forth in this Amendment;

      NOW, THEREFORE, in consideration of the premises and the mutual agreements
contained herein and for other good and valuable consideration, the receipt and
sufficiency of which are hereby acknowledged, the parties hereto hereby agree as
follows:

      ss.1. Defined Terms. Capitalised terms used herein without definition and
defined in the Loan Agreement shall have the same meanings herein as in the Loan
Agreement.

      ss.2. Amendment to Loan Agreement. The parties hereby agree to amend
ss.9.2(a) of the Loan Agreement, to be effective on the Effective Date (as
defined in ss.6 hereof), by deleting ss.9.2(a)(ix) in its entirety and
substituting therefor the following:

                  "(ix) long-term Indebtedness to IKB Deutsche Industriebank
            which does not exceed DM 10,000,000 in cumulative aggregate amount
            and refinancings thereof which do not exceed the amount refinanced
            provided that such Indebtedness is secured only by the fixed assets
            of the Borrowers,".

      ss.3. Waivers, Ratifications, Etc.

      (a) Nothing contained in this Amendment shall constitute a waiver of,
impair or otherwise affect any Obligations, any other obligation of the
Borrowers or any rights of the Bank consequent thereon.

      (b) Except as expressly amended hereby, the Loan Agreement and all
documents, instruments and agreements related thereto, including, but not
limited to the Loan Documents, are hereby ratified and confirmed in all respects
and shall continue in full force and effect.

      (c) GfE Holding Company, as Guarantor under and as defined in the Holding
Guarantee, hereby (a) consents for all purposes to the amendment of the Loan
Agreement as provided herein, (b) consents to the waiver provided by the Bank
contained herein, (c) confirms that all obligations of the Guarantor under the
Holding Guarantee includes all of the indebtedness, obligations and liabilities
under

<PAGE>   3

the Loan Agreement, as the same may be further amended, varied, substituted,
supplemented, restated or novated and in effect from time to time, and (d)
acknowledges that all references to the "Loan Agreement" in the Holding
Guarantee shall refer to the Loan Agreement as amended by this Amendment. 

      ss.4. Representations and Warranties. Each of the Borrowers hereby
represents and warrants (as a Zusicherung im Wege eines Garantieversprechens) to
the Bank as follows:

      (a) The execution and delivery by such Borrower of this Amendment, and the
performance by such Borrower of its obligations and agreements under the Loan
Agreement as amended and confirmed hereby, are within the corporate authority of
such Borrower, have been authorised by all necessary corporate proceedings on
behalf of each of them, and do not contravene any provision of law or the
charter, other incorporation papers, by-laws or any stock provision or any
amendment thereof to which any of them are a party or of any indenture,
agreement, instrument or undertaking binding upon any or all of them.

      (b) This Amendment and the Loan Agreement as amended hereby constitute
legal, valid and binding obligations of the relevant parties thereto,
enforceable in accordance with their respective terms, except as limited by
bankruptcy, insolvency, reorganisation, moratorium or similar laws relating to
or affecting generally the enforcement of creditors' rights.

      (c) No approval or consent of, or filing with, any governmental agency or
authority is required to make valid and legally binding the execution, delivery
or performance by any of them of this Amendment, or the performance by the
Borrowers of the Loan Agreement as amended hereby.

      (d) The representations and warranties contained in ss.7 of the Loan
Agreement were correct at and as of the date made and are correct as of the date
hereof except to the extent of changes resulting from transactions contemplated
or permitted by this Amendment or the Loan Agreement and changes occurring in
the ordinary course of business that singly or in the aggregate are not
materially adverse and except to the extent that such representations and
warranties relate expressly to an earlier date; provided that all references
therein to the Loan Agreement shall refer to such Loan Agreement as amended
hereby.

      (e) As of the date hereof, after giving effect to the provisions hereof,
there exists no Event of Default. 

      ss.5. Conditions to Effectiveness. The effectiveness of this Amendment
shall be subject to the following conditions precedent:

      (a) Corporate Action. All corporate action necessary for the valid
execution, delivery and performance by each of the Borrowers of this Amendment
shall have been duly and effectively taken, and evidence thereof satisfactory to
the Bank shall have been provided to the Bank.

      (b) Delivery. The Borrowers and the Bank shall have executed and delivered
this Amendment and all other documents (in form and substance satisfactory to
the Bank in its sole discretion) contemplated thereby and incident thereto.

      (c) Proceedings and Documents. All proceedings in connection with the
transactions contemplated by this Amendment and all documents incident thereto
shall be reasonably satisfactory in substance and form to the Bank, and the Bank
shall have received all information and such counterpart originals or certified
or other copies of such documents as the Bank may reasonably request.


                                       2
<PAGE>   4

      ss.6. Effective Date. The provisions of this Amendment shall become
effective as of the date (the "Effective Date") which is the later of the date
hereof and the date when the last of the conditions set out in ss.5 has been
satisfied.

      ss.7. Miscellaneous Provisions.

      (a) Except as otherwise expressly provided by this Amendment, all of the
terms, conditions and provisions of the Loan Agreement shall remain the same. It
is declared and agreed by each of the parties hereto that the Loan Agreement, as
amended hereby, shall continue in full force and effect, and that this Amendment
and the Loan Agreement shall be read and construed as one instrument, and that
all references in the Loan Agreement or any of the other Loan Documents to the
Loan Agreement shall refer to the Loan Agreement as amended by this Amendment.

      (b) This Amendment is a contract under the laws of the Federal Republic of
Germany and shall be construed in accordance therewith and governed thereby. 

      (c) This Amendment may be executed in any number of counterparts, but all
such counterparts shall together constitute but one instrument. In making proof
of this Amendment it shall not be necessary to produce or account for more than
one counterpart signed by each party hereto by and against which enforcement
hereof is sought.


                                       3
<PAGE>   5

AS WITNESS the hands of the authorized signatories of the parties hereto the day
and year first above written.

SIGNED by for and on behalf of                  )
GfE Gesellschaft fur Elektrometallurgie         ) /s/ Authorized Signatory
mit beschrankter Haftung in the presence of:-   )

Witness Signature:

Name:

Address:

Occupation:

SIGNED by for and on behalf of             )
GfE Umwelttechnik GmbH                     ) /s/ Authorized Signatory
in the presence of:-                       )

Witness Signature:

Name:

Address:

Occupation:

SIGNED by for and on behalf of                  )
GfE Gie(beta)erei- und Stahlwerksbedarf GmbH    ) /s/ Authorized Signatory
 in the presence of:-                           )

Witness Signature:

Name:

Address:

Occupation:

                              All above signatures of the Managing Directors are
                              witnessed by:


                              /s/ Susanne Kramm 
                              __________________________________________________
                              Susanne Kramm, Sudetenstr. 2c, D-90614 Neuhof
                              Secretary


                                       4
<PAGE>   6

SIGNED by for and on behalf of             )
GfE Metalle und Materialien GmbH           ) /s/ Authorized Signatory
in the presence of:-                       )

Witness Signature:

Name:

Address:

Occupation:

SIGNED by for and on behalf of             )
KERAMED Medizintechnik GmbH                ) /s/ Authorized Signatory
in the presence of:-                       )

Witness Signature:

Name:

Address:

Occupation:

SIGNED by for and on behalf of             )
BankBoston, N.A., London Branch            ) /s/ Authorized Signatory
in the presence of:-                       )

Witness Signature:

Name:

Address:

Occupation:

                              All above signatures of the Managing Directors are
                              witnessed by:


                              /s/ Susanne Kramm
                              __________________________________________________
                              Susanne Kramm, Sudetenstr. 2c, D-90614 Neuhof
                              Secretary


                                       5
<PAGE>   7

                                SECOND AMENDMENT

                                       to

                                 LOAN AGREEMENT

      This SECOND AMENDMENT (this "Amendment"), dated as of 16th November 1998
by and among (a) GfE Gesellschaft fur Elektrometallurgie mit beschrankter
Haftung, a German corporation having its principal place of business at Hofener
Stra(beta)e 45, 90431 Nurnberg ("GfE Holding Company"), GfE Umwelttechnik GmbH,
a German corporation having its principal place of business at Hofener
Stra(beta)e 45, 90431 Nurnberg, ("GfE UT"), GfE Gie(beta)erei- und
Stahlwerksbedarf GmbH, a German corporation having its principal place of
business at KreuzStra(beta)e 45, 40210 Dusseldorf ("GfE G&S"), GfE Metalle und
Materialien GmbH, a German corporation having its principal place of business at
Hofener Stra(beta)e 45, 90431 Nurnberg ("GfE M&M"), KERAMED Medizintechnik GmbH,
a German corporation having its principal place of business at An den Trillers
Buschen 2, 07646 Morsdorf/Thuringen ("KERAMED", and collectively with GfE
Holding Company, GfE UT, GfE G&S and GfE M&M, the "Borrowers"), and (b)
BankBoston, N.A., London Branch (the "Bank") is an amendment of the Loan
Agreement dated 22 July 1998 by among the Borrowers and the Bank (as so amended,
the "Loan Agreement").

      WHEREAS, the Borrowers have requested, and the Bank has agreed, subject to
the terms and conditions set forth herein, to make certain amendments to the
Loan Agreement as specifically set forth in this Amendment;

      NOW, THEREFORE, in consideration of the premises and the mutual agreements
contained herein and for other good and valuable consideration, the receipt and
sufficiency of which are hereby acknowledged, the parties hereto hereby agree as
follows:

      ss.1. Defined Terms. Capitalized terms used herein without definition and
defined in the Loan Agreement shall have the same meanings herein as in the Loan
Agreement.

      ss.2. Amendments to Loan Agreement. The parties hereby agree to amend the
Loan Agreement, to be effective on the Effective Date (as defined in ss.6
hereof), as follows:

      (a) ss.7(o) of the Loan Agreement is hereby deleted in its entirety and
replaced with the following:

            "(o) Schedule 7(o) sets forth the account numbers and location of
            all bank accounts of such Borrower and each of its Subsidiaries
            (excluding the bank account maintained by GfE Holding Company with
            Bank Mendes and subject to the ISO Agreement (as such terms are
            defined in ss.9.2(a)(xii)))."

      (b) ss.9.2(a) of the Loan Agreement is hereby amended as follows:

            (i) by deleting the word "and" from the end of ss.9.2(a)(x);

            (ii) by inserting at the end of ss.9.2(a)(xi) the word "and"; and

            (iii) by inserting at the end of ss.9.2(a) the following:

                  "(xii) unsecured Indebtedness owed (A) by any Borrower to
            Metallurg, Inc., and (B) by GfE Holding Company to Bank Mendes Gans
            N.V. ("Bank Mendes") in respect of its borrowings under that certain
            Interest Set-Off Agreement with Bank Mendes dated 30 
<PAGE>   8

            September 1998 in the form delivered to the Bank prior to the
            Effective Date (the "ISO Agreement") provided that all such
            Indebtedness permitted under this ss.9.2(a)(xii) does not exceed at
            any time the Deutschemark Equivalent of $16,500,000 in cumulative
            aggregate amount;"

      ss.3. Waivers, Ratifications, Etc.

      (a) Nothing contained in this Amendment shall constitute a waiver of,
impair or otherwise affect any Obligations, any other obligation of the
Borrowers or any rights of the Bank consequent thereon.

      (b) Except as expressly amended hereby, the Loan Agreement and all
documents, instruments and agreements related thereto, including, but not
limited to the Loan Documents, are hereby ratified and confirmed in all respects
and shall continue in full force and effect.

      (c) GfE Holding Company, as Guarantor under and as defined in the Holding
Guarantee, hereby (i) consents for all purposes to the amendment of the Loan
Agreement as provided herein, (ii) consents to the waiver provided by the Bank
contained herein, (iii) confirms that all obligations of the Guarantor under the
Holding Guarantee includes all of the indebtedness, obligations and liabilities
under the Loan Agreement, as the same may be further amended, varied,
substituted, supplemented, restated or novated and in effect from time to time,
and (iv) acknowledges that all references to the "Loan Agreement" in the Holding
Guarantee shall refer to the Loan Agreement as amended by this Amendment.

      ss.4. Representations and Warranties. Each of the Borrowers hereby
represents and warrants (as a Zusicherung im Wege eines Garantieversprechens) to
the Bank as follows:

      (a) The execution and delivery by such Borrower of this Amendment, and the
performance by such Borrower of its obligations and agreements under the Loan
Agreement as amended and confirmed hereby, are within the corporate authority of
such Borrower, have been authorised by all necessary corporate proceedings on
behalf of each of them, and do not contravene any provision of law or the
charter, other incorporation papers, by-laws or any stock provision or any
amendment thereof to which any of them are a party or of any indenture,
agreement, instrument or undertaking binding upon any or all of them.

      (b) This Amendment and the Loan Agreement as amended hereby constitute
legal, valid and binding obligations of the relevant parties thereto,
enforceable in accordance with their respective terms, except as limited by
bankruptcy, insolvency, reorganisation, moratorium or similar laws relating to
or affecting generally the enforcement of creditors' rights.

      (c) No approval or consent of, or filing with, any governmental agency or
authority is required to make valid and legally binding the execution, delivery
or performance by any of them of this Amendment, or the performance by the
Borrowers of the Loan Agreement as amended hereby.

      (d) The representations and warranties contained in ss.7 of the Loan
Agreement were correct at and as of the date made and are correct as of the date
hereof except to the extent of changes resulting from transactions contemplated
or permitted by this Amendment or the Loan Agreement and changes occurring in
the ordinary course of business that singly or in the aggregate are not
materially adverse and except to the extent that such representations and
warranties relate expressly to an earlier date; provided that all references
therein to the Loan Agreement shall refer to such Loan Agreement as amended
hereby.

      (e) As of the date hereof, after giving effect to the provisions hereof,
there exists no Event of Default. 


                                       2
<PAGE>   9

      ss.5. Conditions to Effectiveness. The effectiveness of this Amendment
shall be subject to the following conditions precedent:

      (a) Corporate Action. All corporate action necessary for the valid
execution, delivery and performance by each of the Borrowers of this Amendment
shall have been duly and effectively taken, and evidence thereof satisfactory to
the Bank shall have been provided to the Bank.

      (b) Delivery. The Borrowers and the Bank shall have executed and delivered
this Amendment and all other documents (in form and substance satisfactory to
the Bank in its sole discretion) contemplated thereby and incident thereto.

      (c) ISO Agreement. The Bank shall have received a fully executed copy of
the ISO Agreement.

      (d) Bank Mendes Letter. GfE Holding Company shall have delivered to Bank
Mendes a letter, in form and substance satisfactory to the Bank, instructing
Bank Mendes, in the event it enforces its rights under the ISO Agreement, to pay
to the Bank any surplus amounts in the account that GfE Holding Company has with
Bank Mendes.

      (e) Proceedings and Documents. All proceedings in connection with the
transactions contemplated by this Amendment and all documents incident thereto
shall be reasonably satisfactory in substance and form to the Bank, and the Bank
shall have received all information and such counterpart originals or certified
or other copies of such documents as the Bank may reasonably request. 

      ss.6. Effective Date. The provisions of this Amendment shall become
effective as of the date (the "Effective Date") which is the later of the date
hereof and the date when the last of the conditions set out in ss.5 has been
satisfied.

      ss.7. Miscellaneous Provisions.

      (a) Except as otherwise expressly provided by this Amendment, all of the
terms, conditions and provisions of the Loan Agreement shall remain the same. It
is declared and agreed by each of the parties hereto that the Loan Agreement, as
amended hereby, shall continue in full force and effect, and that this Amendment
and the Loan Agreement shall be read and construed as one instrument, and that
all references in the Loan Agreement or any of the other Loan Documents to the
Loan Agreement shall refer to the Loan Agreement as amended by this Amendment.

      (b) This Amendment is a contract under the laws of the Federal Republic of
Germany and shall be construed in accordance therewith and governed thereby. 

      (c) This Amendment may be executed in any number of counterparts, but all
such counterparts shall together constitute but one instrument. In making proof
of this Amendment it shall not be necessary to produce or account for more than
one counterpart signed by each party hereto by and against which enforcement
hereof is sought.


                                       3
<PAGE>   10

AS WITNESS the hands of the authorised signatories of the parties hereto the day
and year first above written.

SIGNED by for and on behalf of                  )
GfE Gesellschaft fur Elektrometallurgie         ) /s/ Authorized Signatory
mit beschrankter Haftung in the presence of:-   )

Witness Signature:

Name:

Address:

Occupation:

SIGNED by for and on behalf of             )
GfE Umwelttechnik GmbH                     ) /s/ Authorized Signatory
in the presence of:-                       )

Witness Signature:

Name:

Address:

Occupation:

SIGNED by for and on behalf of                  )
GfE Gie(beta)erei- und Stahlwerksbedarf GmbH    ) /s/ Authorized Signatory
in the presence of:-                            )

Witness Signature:

Name:

Address:

Occupation:

                              All above signatures of the Managing Directors of
                              the borrowers are witnessed by:

                              /s/ Susanne Kramm
                              __________________________________________________
                              Susanne Kramm, Sudetenstr. 2c, D-90614 Neuhof
                              Secretary


                                       4
<PAGE>   11

SIGNED by for and on behalf of             )
GfE Metalle und Materialien GmbH           ) /s/ Authorized Signatory
in the presence of:-                       )

Witness Signature:

Name:

Address:

Occupation:

SIGNED by for and on behalf of             )
KERAMED Medizintechnik GmbH                ) /s/ Authorized Signatory
in the presence of:-                       )

Witness Signature:

Name:

Address:

Occupation:

SIGNED by for and on behalf of             )
BankBoston, N.A., London Branch            ) /s/ Authorized Signatory
in the presence of:-                       )

Witness Signature:

Name:

Address:

Occupation:

                              All above signatures of the Managing Directors of
                              the borrowers are witnessed by:

                              /s/ Susanne Kramm
                              __________________________________________________
                              Susanne Kramm, Sudetennstr. 2c, D-90614 Neuhof
                              Secretary


                                       5
<PAGE>   12

                                                                       Exhibit A

                                SECOND AMENDMENT

                                       to

                                 LOAN AGREEMENT

      This SECOND AMENDMENT (this "Amendment"), dated as of November 1998 by and
among (a) GfE Gesellschaft fur Elektrometallurgie mit beschrankter Haftung, a
German corporation having its principal place of business at Hofener Straae 45,
90431 N?rnberg ("GfE Holding Company"), GfE Umwelttechnik GmbH, a German
corporation having its principal place of business at Hofener Stra(beta)e 45,
90431 Nurnberg ("GfE UT"), GfE Gieaerei- und Stahlwerksbedarf GmbH, a German
corporation having its principal place of business at KreuzStraae 34, 40210
D?sseldorf ("GfE G&S"), GfE Metalle und Matrialien GmbH, a German corporation
having its principal place of business at Hofener Stra(beta)e 45, 90431 Nurnberg
("GfE M&M"), KERAMED Medizintechnik GmbH, a German corporation having its
principal place of business at An den Trillers Buschen 2, 07646
Morsdorf/Thuringen ("KERAMED," and collectively with GfE Holding Company, GfE
UT, GfE G&S and GfE M&M, the "Borrowers"), and (b) BankBoston, N.A., London
Branch (the "Bank") is an amendment of the Loan Agreement dated 22 July 1998 by
and among the Borrowers and the Bank (as so amended, the "Loan Agreement").

      WHEREAS, the Borrowers have requested, and the Bank has agreed, subject to
the terms and conditions set forth herein, to make certain amendments to the
Loan Agreement as specifically set forth in this Amendment;

      NOW, THEREFORE, in consideration of the premises and the mutual agreements
contained herein and for other good and valuable consideration, the receipt and
sufficiency of which are hereby acknowledged, the parties hereto hereby agree as
follows:

      ss. 1. Defined Terms. Capitalised terms used herein without definition and
defined in the Loan Agreement shall have the same meanings herein as in the Loan
Agreement.

      ss. 2. Amendments to Loan Agreement. The parties hereby agree to amend the
Loan Agreement, to be effective on the Effective Date (as defined in ss.6
hereof), as follows:

      (a) ss.7(o) of the Loan Agreement is hereby deleted in its entirety and
replaced with the following:

                  "(o) Schedule 7(o) sets forth the account numbers and location
            of all bank accounts of such Borrower and each of its Subsidiaries
            (excluding the bank account maintained by GfE Holding Company with
            Bank Mendes and subject to the ISO Agreement (as such terms are
            defined in ss.9.2(a)(xii)))."

      (b) ss.9.2(a) of the Loan Agreement is hereby amended as follows:

            (i) by deleting the word "and" from the end of ss.9.2(a)(x);

            (ii) by inserting at the end of ss.9.2(a)(xi) the word "and"; and

<PAGE>   13
                                      -2-


            (iii) by inserting at the end of ss.9.2(a) the following:

                  "(xii) unsecured Indebtedness owed (A) by any Borrower to
            Metallurg, Inc., and (B) by GfE Holding Company to Bank Mendes Gans
            N.V. ("Bank Mendes") in respect of its borrowings under that certain
            Interest Set-Off Agreement with Bank Mendes dated 30 September 1998
            in the form delivered to the Bank prior to the Effective Date (the
            "ISO Agreement") provided that all such Indebtedness permitted under
            this ss.9.2(a)(xii) does not exceed at any time the Deutschemark
            Equivalent of $16,500,000 in cumulative aggregate amount;"

      ss. 3. Waivers, Ratifications, Etc.

      (a) Nothing contained in this Amendment shall constitute a waiver of,
impair or otherwise affect any Obligations, any other obligation of the
Borrowers or any rights of the Bank consequent thereon.

      (b) Except as expressly amended hereby, the Loan Agreement and all
documents, instruments and agreements related thereto, including, but not
limited to the Loan Documents, are hereby ratified and confirmed in all respects
and shall continue in full force and effect.

      (c) GfE Holding Company, as Guarantor under and as defined in the Holding
guarantee, hereby (i) consents for all purposes to the amendment of the Loan
Agreement as provided herein, (ii) consents to the waiver provided by the Bank
contained herein, (iii) confirms that all obligations of the Guarantor under the
Holding Guarantee includes all of the indebtedness, obligations and liabilities
under the Loan agreement, as the same may be further amended, varied,
substituted, supplemented, restated or novated and in effect from time to time,
and (iv) acknowledges that all references to the "Loan Agreement" in the Holding
Guarantee shall refer to the Loan Agreement as amended by this Amendment.

      ss. 4. Representations and Warranties. Each of the Borrowers hereby
represents and warrants (as a Zusicherung im Wege eines Garantieversprechens) to
the Bank as follows:

      (a) The execution and delivery by such Borrower of this Amendment, and the
performance by such Borrower of its obligations and agreements under the Loan
Agreement as amended and confirmed hereby, are within the corporate authority of
such Borrower, have been authorised by all necessary corporate proceedings on
behalf of each of them, and do not contravene any provision of law or the
charter, other incorporation papers, by-laws or any stock provision or any
amendment thereof to which any of them are a party or of any indenture,
agreement, instrument or undertaking binding upon any or all of them

      (b) This Amendment and the Loan Agreement as amended hereby constitute
legal, valid and binding obligations of the relevant parties thereto,
enforceable in accordance with their respective terms, except as limited by
bankruptcy, insolvency, reorganisation, moratorium or similar laws relating to
or affecting generally the enforcement of creditors' rights.

      (c) No approval or consent of, or filing with, any governmental agency or
authority is required to make valid and legally binding the execution, delivery
or performance by any of them of this Amendment, or the performance by the
Borrowers of the Loan Agreement as amended hereby.

      (d) The representations and warranties contained in ss.7 of the Loan
Agreement were correct at and as of the date made and are correct as of the date
hereof except to the extent of changes resulting from transactions contemplated
or permitted by this Amendment or the Loan Agreement and changes 

<PAGE>   14
                                      -3-


occurring in the ordinary course of business that singly or in the aggregate are
not materially adverse and except to the extent that such representations and
warranties relate expressly to an earlier date; provided that all references
therein to the Loan Agreement shall refer to such Loan Agreement as amended
hereby.

      (e) As of the date hereof, after giving effect to the provisions hereof,
there exists no Event of Default.

      ss. 5. Conditions to Effectiveness. The effectiveness of this Amendment
shall be subject to the following conditions precedent:

      (a) Corporate Action. All corporate action necessary for the valid
execution, delivery and performance by each of the Borrowers of this Amendment
shall have been duly and effectively taken, and evidence thereof satisfactory to
the Bank shall have been provided to the Bank.

      (b) Delivery. The Borrowers and the Bank shall have executed and delivered
this Amendment and all other documents (in form and substance satisfactory to
the Bank in its sole discretion) contemplated thereby and incident thereto.

      (c) ISO Agreement. The Bank shall have received a fully executed copy of
the ISO Agreement.

      (d) Bank Mendes Letter. GfE Holding Company shall have delivered to Bank
Mendes a letter, in form and substance satisfactory to the Bank, instructing
Bank Mendes, in the event it enforces its rights under the ISO Agreement, to pay
to the Bank any surplus amounts in the account that GfE Holding Company has with
Bank Mendes.

      (e) Proceedings and Documents. All proceedings in connection with the
transactions contemplated by this Amendment and all documents incident thereto
shall be reasonably satisfactory in substance and form to the Bank, and the Bank
shall have received all information and such counterpart originals or certified
or other copies of such documents as the Bank may reasonably request.

      ss. 6. Effective Date. The provisions of this Amendment shall become
effective as of the date (the "Effective Date") which is the later of the date
hereof and the date when the last of the conditions set out in ss.5 has been
satisfied.

      ss. 7. Miscellaneous Provisions.

      (a) Except as otherwise expressly provided by this Amendment, all of the
terms, conditions and provisions of the Loan Agreement shall remain the same. It
is declared and agreed by each of the parties hereto that the Loan Agreement, as
amended hereby, shall continue in full force and effect, and that this Amendment
and the Loan Agreement shall be read and construed as one instrument, and that
all references in the Loan Agreement or any of the other Loan Documents to the
Loan Agreement shall refer to the Loan Agreement as amended by this Amendment.

      (b) This Amendment is a contract under the laws of the Federal Republic of
Germany and shall be construed in accordance therewith and governed thereby.

      (c) This Amendment may be executed in any number of counterparts, but all
such counterparts shall together constitute but one instrument. In making proof
of this Amendment it shall not be necessary to produce or account for more than
one counterpart signed by each party hereto by and against which enforcement
hereof is sought.

<PAGE>   15
                                      -4-


      AS WITNESS the hands of the authorised signatories of the parties hereto
the day and year first above written.

SIGNED by for and on behalf of                        )
GfE Gesellschaft fur Elektrometallurgie               ) /s/ Authorized Signatory
mit beschrankter Haftung in the presence of:-         )

Witness Signature:

Name:

Address:

Occupation:

SIGNED by for and on behalf of                  )
GfE Umwelttechnik GmbH                          ) /s/ Authorized Signatory
in the presence of:-                            )

Witness Signature:

Name:

Address:

Occupation:

SIGNED by for and on behalf of                       )
GfE Gie(beta)erei- und Stahlwerksbedarf GmbH         ) /s/ Authorized Signatory
in the presence of:-                                 )

Witness Signature:

Name:

Address:

Occupation:

<PAGE>   16
                                      -5-


SIGNED by for and on behalf of                  )
GfE Metalle und Materialien GmbH                ) /s/ Authorized Signatory
in the presence of:-                            )

Witness Signature:

Name:

Address:

Occupation:

SIGNED by for and on behalf of                  )
KERAMED Medizintechnik GmbH                     ) /s/ Authorized Signatory
in the presence of:-                            )

Witness Signature:

Name:

Address:

Occupation:

SIGNED by for and on behalf of                  )
BankBoston, N.A., London Branch                 ) /s/ Authorized Signatory
in the presence of:-                            )

Witness Signature:

Name:

Address:

Occupation: