EXCHANGE AGREEMENT

                            exchanging

  2,252 SHARES OF SERIES 10 CLASS J CONVERTIBLE PREFERRED STOCK,

                    PAR VALUE $.001 PER SHARE

                                of

              PERMA-FIX ENVIRONMENTAL SERVICES, INC.
                     (a Delaware corporation)

                               for

  2,252 SHARES OF SERIES 13 CLASS M CONVERTIBLE PREFERRED STOCK,

                    PAR VALUE $.001 PER SHARE


                                of

              PERMA-FIX ENVIRONMENTAL SERVICES, INC.
                     (a Delaware corporation)







                        TABLE OF CONTENTS

                                                             Page

1.   Exchange and Subscription for Purchase of Securities. . . .3
     1.1  Issuance of Common Stock and Warrants. . . . . . . . .3
          1.1.1     Delivery . . . . . . . . . . . . . . . . . .3
          1.1.2     Cancellation of Series 10 Preferred. . . . .4
          1.1.3     Restrictive Legends. . . . . . . . . . . . .4
     1.2  Discharge. . . . . . . . . . . . . . . . . . . . . . .4
     1.3  Exchange . . . . . . . . . . . . . . . . . . . . . . .4
     1.4  Reporting Company. . . . . . . . . . . . . . . . . . .4
     1.5  Terms of the Series 13 Preferred . . . . . . . . . . .5
     1.6  No Effect on Series 10 Warrants. . . . . . . . . . . .5

2.   Closing . . . . . . . . . . . . . . . . . . . . . . . . . .5
     2.1  Closing. . . . . . . . . . . . . . . . . . . . . . . .5

3.   Representations, Warranties and Covenants of Subscriber . .5
     3.1  Investment Intent. . . . . . . . . . . . . . . . . . .5
     3.2  Certain Risk . . . . . . . . . . . . . . . . . . . . .5
     3.3  Prior Investment Experience. . . . . . . . . . . . . .6
     3.4  No Review by the SEC . . . . . . . . . . . . . . . . .6
     3.5  Not Registered . . . . . . . . . . . . . . . . . . . .6
     3.6  No Public Market . . . . . . . . . . . . . . . . . . .6
     3.7  Sophisticated Investor . . . . . . . . . . . . . . . .7
     3.8  Tax Consequences . . . . . . . . . . . . . . . . . . .7
     3.9  SEC Filing . . . . . . . . . . . . . . . . . . . . . .7
     3.10 Documents, Information and Access. . . . . . . . . . .8
     3.11 No Registration, Review or Approval. . . . . . . . . .8
     3.12 Transfer Restrictions. . . . . . . . . . . . . . . . .8
     3.13 No Short Sale. . . . . . . . . . . . . . . . . . . . .8
     3.14 No Commission. . . . . . . . . . . . . . . . . . . . .9
     3.15 Reliance . . . . . . . . . . . . . . . . . . . . . . .9
     3.16 Accuracy or Representations and Warranties . . . . . .9
     3.17 Indemnity. . . . . . . . . . . . . . . . . . . . . . .9
     3.18 Survival . . . . . . . . . . . . . . . . . . . . . . .9

4.   Representations, Warranties and Covenants of the Company. 10
     4.1  Organization, Authority, Qualification . . . . . . . 10
     4.2  Authorization. . . . . . . . . . . . . . . . . . . . 10
     4.3  No Commission. . . . . . . . . . . . . . . . . . . . 10
     4.4  Ownership of, and Title to, Securities . . . . . . . 10


                               -i-


     4.5  Exemption from Registration. . . . . . . . . . . . . 10

5.   Registration Rights . . . . . . . . . . . . . . . . . . . 11

6.   Indemnification.. . . . . . . . . . . . . . . . . . . . . 11
     6.1  By the Company . . . . . . . . . . . . . . . . . . . 11
     6.2  By the Subscriber. . . . . . . . . . . . . . . . . . 11
     6.3  Procedure. . . . . . . . . . . . . . . . . . . . . . 12

7.   Securities Legends and Notices. . . . . . . . . . . . . . 12

8.   Miscellaneous.

     8.1  Assignment and Power of Attorney. . . . . . . . . . .14
     8.2  Amendment; Waiver. . . . . . . . . . . . . . . . . . 14
     8.3  Binding Effect; Assignment . . . . . . . . . . . . . 14
     8.4  Governing Law; Litigation Costs. . . . . . . . . . . 14
     8.5  Severability . . . . . . . . . . . . . . . . . . . . 15
     8.6  Headings . . . . . . . . . . . . . . . . . . . . . . 15
     8.7  Counterparts . . . . . . . . . . . . . . . . . . . . 15
     8.8  Transfer Taxes . . . . . . . . . . . . . . . . . . . 15
     8.9  Entire Agreement . . . . . . . . . . . . . . . . . . 15
     8.10 Authority; Enforceability. . . . . . . . . . . . . . 15
     8.11 Notices. . . . . . . . . . . . . . . . . . . . . . . 16
     8.12 No Third Party Beneficiaries . . . . . . . . . . . . 16
     8.13 Public Announcements . . . . . . . . . . . . . . . . 16
     8.14 Conflicts with Subscription Agreement. . . . . . . . 17

Exhibit "A"    Certificate of Designations














                               -ii-



      THIS EXCHANGE AGREEMENT (the "Agreement") is entered on the
15th day of July 1999, by and between PERMA-FIX ENVIRONMENTAL
SERVICES, INC., a Delaware corporation, having offices at 1940
Northwest 67th Place, Gainesville, Florida 32653 (the "Company"),
and RBB BANK AKTIENGESELLSCHAFT, organized under the laws of
Austria, and having its principal offices at Burgring 16, 8101
Graz, Austria (the "Subscriber").

                       W I T N E S S E T H:

     WHEREAS, the Company and the Subscriber previously entered
into a certain Private Securities Subscription Agreement dated June
30, 1998 ("Subscription Agreement") under which (i) 3,000 shares of
"Series 10 Class Convertible Preferred Stock," par value $.001 per
share (the "Series 10 Preferred"), and (ii) an aggregate of 350,000
common stock purchase warrants were issued to the Subscriber in the
form of one common stock purchase warrant dated June 30, 1998,
providing for the purchase of 200,000 shares of the Company's
common stock, par value $.001 per share (the "Common Stock"), at an
exercise price of $1.875 per share, and one common stock warrant
dated June 30, 1998, providing for the purchase of 150,000 shares
of Common Stock at an exercise price of $2.50 per share
(collectively, the "Series 10 Warrants")(the Common Stock issuable
upon the exercise of the Series 10 Warrants is referred to
hereinafter as the "Warrant Shares");

     WHEREAS, pursuant to the terms of the Series 10 Preferred, the
Subscriber has previously converted seven hundred forty-eight (748)
shares of Series 10 Preferred into Common Stock leaving two
thousand two hundred fifty-two (2,252) shares remaining issued and
outstanding as of the date of this Agreement;

     WHEREAS, the subscriber owns all of the issued and outstanding
shares of Series 10 Preferred as of the date of this Agreement;

     WHEREAS, the Company and the Subscriber both desire to enter
into this Agreement,  under which all of the issued and outstanding
shares of the Series 10 Preferred will be delivered and tendered to
the Company in exchange (the "Exchange") for an aggregate of two
thousand two hundred fifty-two (2,252) shares of a new series of
convertible preferred stock, par value $.001 per share, to be
designated by the Company's Board of Directors as "Series 13 Class
M Convertible Preferred Stock" (the "Series 13 Preferred"), with
the Series 13 Preferred  containing such terms, conditions,
restrictions and provisions as set forth in the Series 13 Preferred
Certificate of Designations, attached hereto as Exhibit "A,"
("Series 13 Preferred Certificate of Designations");

     WHEREAS, the Subscription Agreement is not terminated, except
from and after the date of this Agreement (i) the Subscriber shall
have no rights under the Subscription Agreement or otherwise
arising out of or in connection with or relating to the Series 10
Preferred or to subscribe for Series 10 Preferred or any shares of
Common Stock issuable or obtainable upon conversion of the Series
10 Preferred and (ii) if the Subscription Agreement is in conflict
with this Agreement, this Agreement shall control in all respects;

                               -1-


     WHEREAS, the terms, conditions, restrictions and provisions of
the Series 13 Preferred shall be the same as the terms, conditions,
restrictions and provisions of the Series 10 Preferred, except that
(i) the Series 13 Preferred shall not be convertible for a period
of twelve months from the date of this Agreement, (ii) the Minimum
Conversion Price (as defined herein) shall be $1.50 for a period of
twenty-four months from the date of issuance of the Series 13
Preferred, (iii) the Company shall, at any time and from time to
time within 120 days from the date of issuance of the Series 13
Preferred have the option to redeem up to 450 shares of Series 13
Preferred of the 2,252 currently outstanding for $1,000 per share,
and upon such redemption the holder of the Series 13 Preferred so
redeemed shall not have the right to convert such redeemed shares,
(iv) for a period of twelve months from the date of issuance of the
Series 13 Preferred, the Company shall at any time and from time to
time, have the option of redeeming the Series 13 Preferred for
$1,100 per share, except as otherwise provided in (iii) above, and
upon such redemption the holder of the Series 13 Preferred so
redeemed shall not have the right to convert such redeemed shares,
(v) after a period of twelve months from the date of issuance of
the Series 13 Preferred, the Company shall, at any time and from
time to time, have the option of redeeming the Series 13 Preferred
for $1,200 per share, and (vi) after a period of twelve months from
the date of the issuance of the Series 13 Preferred, upon receipt
of notice of redemption, the holder of the Series 13 Preferred
being redeemed shall have five business days in which to exercise
an option to convert some or all of the shares of Series 13
Preferred being redeemed by the Company;

     WHEREAS, the Series 10 Warrants shall not be affected by this
Agreement and shall remain issued and outstanding pursuant to the
terms, provisions and conditions of the Series 10 Warrants;

     WHEREAS, the shares of Common Stock issuable upon conversion
of the Series 13 Preferred ("Conversion Shares") and the Series 13
Preferred are collectively referred to hereinafter as the
"Securities;"

     WHEREAS, the Company and the Subscriber each desire that the
Exchange and the execution of the Agreement act to fully and
completely terminate the Subscriber's rights under the Series 10
Preferred, terminate the Series 10 Preferred and will act to fully
and completely release all obligations of the Company under the
Series 10 Preferred;

     WHEREAS, the Common Stock is listed for trading on the Boston
Stock Exchange and the National Association of Securities Dealers
Automated Quotation SmallCap market ("NASDAQ"), and the Company is
subject to the reporting requirements of Section 13 or 15(d) of the
Securities Exchange Act of 1934, as amended (the "Exchange Act")
and has been subject to such filing requirements for the past
ninety (90) days;

     WHEREAS, the Subscriber is an "accredited investor," as such
term is defined in Rule 501 of Regulation D promulgated under the
Securities Act of 1933, as amended (the "Securities Act") and the
Subscriber received all information as required under Rule 502 of
Regulation D.;

                               -2-


     WHEREAS, the Subscriber is not a "U. S. Person," as such term
is defined in Regulation S promulgated under the Securities Act;

     WHEREAS, in reliance upon the representations made by the
Subscriber in this Agreement, the transactions contemplated by this
Agreement are such that the offer and exchange of securities by the
Company hereunder will be exempt from registration under applicable
federal (U. S.) securities laws since this is an exchange offer
pursuant to Section 3(a)(9) of the Securities Act, and it is a
private placement and intended to be a nonpublic offering pursuant
to Section 4(2) of the Securities Act and/or Regulation D
promulgated under the Securities Act; and,

     WHEREAS, the Securities will not be quoted or listed for
trading on any securities exchange, organized market or quotation
system at the time of acquisition hereunder.

     NOW, THEREFORE, for and in consideration of the premises, and
the mutual representations, warranties, covenants and agreements
set forth herein, and for other good and valuable consideration,
receipt of which is hereby acknowledged, the parties hereto agree
as follows:

1.   Exchange and Subscription for Purchase of Securities.

     1.1  Issuance of Common Stock and Warrants.   In full and
          complete termination of the Series 10 Preferred and the
          Subscriber's rights, and the interest in and to the
          Series 10 Preferred, and in full and complete release of
          any and all obligations of the Company under the Series
          10 Preferred and to the Subscriber under the Series 10
          Preferred, at the Closing (as defined herein) the
          Subscriber shall deliver all of the issued and
          outstanding shares of the Series 10 Preferred to the
          Company in exchange for 2,252 shares of Series 13
          Preferred, containing such terms, conditions and
          provisions as set forth in the Series 13 Preferred
          Certificate of Designations, pursuant to the terms and
          conditions set forth in this Agreement.  Dividends on the
          Series 10 Preferred shall cease to accrue as of the close
          of business on the day immediately preceding the date of
          this Agreement, and dividends on the Series 13 Preferred
          shall begin to accrue on the date of this Agreement.

          1.1.1     Delivery.  Upon receipt by the Company of the
                    canceled Series 10 Preferred duly assigned to
                    the Company, the Company shall deliver or
                    cause to be delivered: (a) to Conner &
                    Winters, A Professional Corporation ("Conner &
                    Winters"), a certificate or certificates
                    representing the 2,252 shares of Series 13
                    Preferred issued in the name of the
                    Subscriber, in such denominations as
                    Subscriber requests in writing, to be held in
                    escrow by Conner & Winters, for the
                    Subscriber; and (b) to the Subscriber, written
                    evidence from the Secretary of State of the
                    State of Delaware that the Series 13 Preferred
                    Certificate of Designations has been filed in
                    the Office of the Secretary of State of the
                    State of Delaware on or before the Closing
                    Date.

                               -3-


          1.1.2     Cancellation of Series 10 Preferred.  At the
                    Closing the Subscriber does hereby assign and
                    transfer unto the Company all of the Series 10
                    Preferred, the Series 10 Preferred shall be
                    terminated and rendered null and void in all
                    respects, and Conner & Winters is directed to
                    deliver to the Company the Series 10 Preferred
                    marked "Canceled."

          1.1.3     Restrictive Legends. Subscriber agrees that
                    all certificates representing the Securities
                    shall bear the restrictive legend
                    substantially in the form set forth in Section
                    7 below which shall include, but not be
                    limited to, a legend to the effect that (a)the
                    Securities represented by such certificate
                    have not been registered under the Securities
                    Act, and (b) unless there is an effective
                    registration statement relating to the
                    Securities, the Securities may not be offered,
                    sold, transferred, mortgaged, pledged or
                    hypothecated without an exemption from
                    registration and an opinion of counsel to the
                    Company with respect thereto, or an opinion
                    from counsel for the Subscriber, which opinion
                    is satisfactory to the Company, to the effect
                    that registration under the Securities Act is
                    not required in connection with such sale or
                    transfer and the reasons therefor.

     1.2  Discharge.  As of the Closing, the Series 10 Preferred
          shall be fully terminated in all respects.  From and
          after the Closing, the Subscriber releases, acquits and
          forever discharges the Company, and all of its respective
          subsidiaries, affiliates, agents, employees, officers,
          and directors, as well as their respective heirs, suc-
          cessors, legal and personal representatives, and assigns
          of any and all of them, from and against any and all
          claims, liabilities, losses, damages, cause or causes of
          action of any kind or character whatsoever, whether
          liquidated, unliquidated or disputed, asserted or
          assertable, known or unknown, in contract or in tort, at
          law or in equity, which the Subscriber might now or
          hereafter have arising out of or in connection with or
          relating to the Series 10 Preferred.

     1.3  Exchange.  On the basis of the representations,
          warranties, covenants and agreements, and subject to the
          terms and conditions set forth herein, at the Closing,
          the Company agrees to exchange and deliver to the
          Subscriber, and the Subscriber agrees to accept in such
          exchange the delivery from the Company, of the Series 13
          Preferred in exchange for the transfer of the Series 10
          Preferred from the Subscriber to the Company.

     1.4  Reporting Company.   The Company is a reporting company
          under the Exchange Act and has filed with the United
          States Securities and Exchange Commission (the "SEC") all
          reports required to be filed by the Company under Section
          13 or 15(d) of the Exchange Act.  The Subscriber has had
          the opportunity to review, and has reviewed, all such
          reports and information which the Subscriber deemed
          material to an investment decision regarding the purchase
          of the Series 13 Preferred.

                               -4-


     1.5  Terms of the Series 13 Preferred.  The Series 13
          Preferred shall contain and be subject to the terms,
          conditions, preferences and restrictions set forth in the
          Series 13 Preferred Certificate of Designations attached
          hereto as Exhibit "A."

     1.6  No Effect on Series 10 Warrants.  Nothing contained in
          this Agreement shall have any effect on the Series 10
          Warrants.

2.   Closing.

     2.1  Closing.  The consummation of this Agreement (the
          "Closing") will occur on at the time and on the date that
          the 2,252 shares of Series 13 Preferred are delivered by
          the Company to Conner & Winters (the "Closing Date").

3.   Representations, Warranties and Covenants of Subscriber.  The
Subscriber hereby represents, warrants and covenants to the Company
as follows:

     3.1  Investment Intent.  The Subscriber represents and
          warrants that the shares of Series 13 Preferred are
          being, and any underlying Conversion Shares will be,
          purchased or acquired solely for the Subscriber's own
          account, for investment purposes only and not with a view
          toward the distribution or resale to others.  The
          Subscriber acknowledges, understands and appreciates that
          the Securities have not been registered under the
          Securities Act by reason of a claimed exemption under the
          provisions of the Securities Act which depends, in large
          part, upon the Subscriber's representations as to
          investment invention, investor status, and related and
          other matters set forth herein.  Subscriber understands
          that, in the view of the SEC, among other things, a
          purchase now with an intent to distribute or resell would
          represent a purchase and acquisition with an intent
          inconsistent with its representation to the Company, and
          the SEC might regard such a transfer as a deferred sale
          for which the registration exemption is not available.

     3.2  Certain Risk.  The Subscriber recognizes that the
          purchase of the Series 13 Preferred involves a high
          degree of risk in that (a) the Company has sustained
          losses through December 31, 1998, from its operations,
          and may require substantial funds in addition to the
          proceeds of this private placement; (b) that the Company
          has a substantial accumulated deficit; (c) an investment
          in the Company is highly speculative and only investors
          who can afford the loss of their entire investment should
          consider investing in the Company and the Series 13
          Preferred; (d) an investor may not be able to liquidate
          his investment; (e) transferability of the Series 13
          Preferred is extremely limited; (f) in the event of a
          disposition an investor could sustain the loss of his
          entire investment; (g) the Series 13 Preferred represent
          non-voting equity securities, and the right to convert
          into and purchase shares of voting equity securities in
          a corporate entity that has an accumulated deficit; (h)
          no return on investment, whether through distributions,

                               -5-


          appreciation, transferability or otherwise, and no
          performance by, through or of the Company, has been
          promised, assured, represented or warranted by the
          Company, or by any director, officer, employee, agent or
          representative thereof; and, (i) while the Common Stock
          is presently quoted and traded on the Boston Stock
          Exchange and the NASDAQ and while the Subscriber is a
          beneficiary of certain registration rights provided
          herein, the Series 13 Preferred subscribed for and that
          are purchased under this Agreement and the Conversion
          Shares (i) are not registered under applicable federal
          (U. S.) or state securities laws, and thus may not be
          sold, conveyed, assigned or transferred unless registered
          under such laws or unless an exemption from registration
          is available under such laws, as more fully described
          herein, and (ii) the Series 13 Preferred subscribed for
          and that are to be purchased under this Agreement are not
          quoted, traded or listed for trading or quotation on the
          NASDAQ, or any other organized market or quotation
          system, and there is therefore no present public or other
          market for the Series 13 Preferred, nor can there be any
          assurance that the Common Stock of the Company will
          continue to be quoted, traded or listed for trading or
          quotation on the Boston Stock Exchange or the NASDAQ or
          on any other organized market or quotation system.

     3.3  Prior Investment Experience.  The Subscriber acknowledges
          that it has prior investment experience, including
          investment in non-listed and non-registered securities,
          or has employed the services of an investment advisor,
          attorney or accountant to read all of the documents
          furnished or made available by the Company to it and to
          evaluate the merits and risks of such an investment on
          its behalf, and that it recognizes the highly speculative
          nature of this investment.

     3.4  No Review by the SEC.  The Subscriber hereby acknowledges
          that this offering of the Series 13 Preferred has not
          been reviewed by the SEC because this private placement
          is intended to be an exchange offer under Section 3(a)(9)
          of the Securities Act and a nonpublic offering pursuant
          to Section 4(2) of the Securities Act and/or Regulation
          D promulgated under the Securities Act.

     3.5  Not Registered.  The Subscriber understands that the
          Series 13 Preferred and the Conversion Shares have not
          been registered under the Securities Act by reason of a
          claimed exemption under the provisions of the Securities
          Act which depends, in part, upon the Subscriber's
          investment intention.  In this connection, the Subscriber
          understands that it is the position of the SEC that the
          statutory basis for such exemption would not be present
          if its representation merely meant that its present
          intention was to hold such securities for a short period,
          such as the capital gains period of tax statutes, for a
          deferred sale, for a market rise (assuming that a market
          develops), or for any other fixed period.

     3.6  No Public Market.  The Subscriber understands that there
          is no public market for the Series 13 Preferred.  The
          Subscriber understands that although there is presently

                               -6-


          a public market for the Common Stock, including the
          Conversion Shares, Rule 144 (the "Rule") promulgated
          under the Securities Act requires, among other
          conditions, a one-year holding period following full
          payment of the consideration therefor prior to the resale
          (in limited amounts) of securities acquired in a
          nonpublic offering without having to satisfy the
          registration requirements under the Securities Act.  The
          Subscriber understands that the Company makes no
          representation or warranty regarding its fulfillment in
          the future of any reporting requirements under the
          Exchange Act, or its dissemination to the public of any
          current financial or other information concerning the
          Company, as is required by the Rule as one of the
          conditions of its availability.  The Subscriber
          understands and hereby acknowledges that the Company is
          under no obligation to register the Series 13 Preferred
          or the Conversion Shares under the Securities Act.  The
          Subscriber agrees to hold the Company and its directors,
          officers and controlling persons and their respective
          heirs, representatives, successors and assigns harmless
          and to indemnify them against all liabilities, costs and
          expenses incurred by them as a result of any
          misrepresentation made by the Subscriber contained herein
          or any sale or distribution by the Subscriber in
          violation of the Securities Act or any applicable state
          securities or "blue sky" laws (collectively, "Securities
          Laws").

     3.7  Sophisticated Investor.  That (a) the Subscriber has
          adequate means of providing for the Subscriber's current
          financial needs and possible contingencies and has no
          need for liquidity of the Subscriber's investment in the
          Series 13 Preferred; (b) the Subscriber is able to bear
          the economic risks inherent in an investment in the
          Series 13 Preferred and that an important consideration
          bearing on its ability to bear the economic risk of the
          purchase of  Series 13 Preferred is whether the
          Subscriber can afford a complete loss of the Subscriber's
          investment in the  Series 13 Preferred and the Subscriber
          represents and warrants that the Subscriber can afford
          such a complete loss; and (c) the Subscriber has such
          knowledge and experience in business, financial,
          investment and banking matters (including, but not
          limited to, investments in restricted, non-listed and
          non-registered securities) that the Subscriber is capable
          of evaluating the merits, risks and advisability of an
          investment in the  Series 13 Preferred.

     3.8  Tax Consequences.  The Subscriber acknowledges that the
          Company has made no representation regarding the
          potential or actual tax consequences for the Subscriber
          which will result from entering into the Agreement and
          from consummation of the Exchange.  The Subscriber
          acknowledges that it bears complete responsibility for
          obtaining adequate tax advice regarding the Agreement and
          the Exchange.

     3.9  SEC Filing.  The Subscriber acknowledges that it has been
          previously furnished with true and complete copies of the
          following documents which have been filed with the SEC
          pursuant to Sections 13(a), 14(a), 14(c) or 15(d) of the
          Exchange Act, and that such have been furnished to the
          Subscriber a reasonable time prior to the date hereof:

                               -7-


          (i) Annual Report on Form 10-K for the year ended
          December 31, 1998 (the "Form 10-K"); (ii) Current Report
          on Form 8-K, date of earliest event reported April 8,
          1999; (iii) Quarterly Report on Form 10-Q for the quarter
          ended March 31, 1999; and (iv) the information contained
          in any reports or documents required to be filed by the
          Company under Sections 13(a), 14(a), 14(c) or 15(d) of
          the Exchange Act since the distribution of the Form 10-K.

     3.10 Documents, Information and Access.  The Subscriber's
          decision to purchase the Series 13 Preferred is not based
          on any promotional, marketing or sales materials, and the
          Subscriber and its representatives have been afforded,
          prior to purchase thereof, the opportunity to ask
          questions of, and to receive answers from, the Company
          and its management, and has had access to all documents
          and information which Subscriber deems material to an
          investment decision with respect to the purchase of
          Series 13 Preferred hereunder.

     3.11 No Registration, Review or Approval.  The Subscriber
          acknowledges and understands that the private offering
          and sale of securities pursuant to this Agreement has not
          been reviewed or approved by the SEC or by any state
          securities commission, authority or agency, and is not
          registered under the Securities Laws.  The Subscriber
          acknowledges, understands and agrees that the shares of
          Series 13 Preferred are being offered and exchanged
          hereunder pursuant to (i) an exchange offer exemption
          under Section 3(a)(9) of the Securities Act and (ii) (x)
          a private placement exemption to the registration
          provisions of the Securities Act pursuant to Section 4(2)
          of such Securities Act and/or Regulation D promulgated
          under the Securities Act) and (y) a similar exemption to
          the registration provisions of applicable state
          securities laws.

     3.12 Transfer Restrictions.  The Subscriber will not transfer
          any Series 13 Preferred Securities purchased under this
          Agreement or any Conversion Shares purchased under this
          Agreement unless such are registered under the Securities
          Laws, or unless an exemption is available under such
          Securities Laws, and the Company may, if it chooses,
          where an exemption from registration is claimed by such
          Subscriber, condition any transfer of Series 13 Preferred
          or Conversion Shares out of the Subscriber's name on
          receipt of an opinion of the Company's counsel, to the
          effect that the proposed transfer is being effected in
          accordance with, and does not violate, an applicable
          exemption from registration under the Securities Laws, or
          an opinion of counsel to the Subscriber, which opinion is
          satisfactory to the Company, to the effect that
          registration under the Securities Act is not required in
          connection with such sale or transfer and the reasons
          therefor.

     3.13 No Short Sale.  The Subscriber expressly agrees that
          until such time that it has sold all of the Securities
          that it shall not, directly or indirectly, through an
          affiliate (as that term is defined under Rule 405
          promulgated under the Securities Act) or by, with or
          through an unrelated third party or entity, whether or
          not pursuant to a written or oral understanding,

                               -8-



         agreement, arrangement, scheme, or artifice of nature
          whatsoever, engage in the short selling of the Company's
          Common Stock or any other equity securities of the
          Company, whether now existing or hereafter issued, or
          engage in any other activity of any nature whatsoever
          that has the same effect as a short sale, or is a de
          facto or de jure short sale, of the Company's Common
          Stock or any other equity security of the Company,
          whether now existing or hereafter issued, including, but
          not limited to, the sale of any rights pursuant to any
          understanding, agreement, arrangement, scheme or artifice
          of any nature whatsoever, whether oral or in writing,
          relative to the Company's Common Stock or any other
          equity securities of the Company whether now existing or
          hereafter created.

               3.14 No Commission.  The Subscriber agrees and acknowledges
          that no commission or other remuneration is being paid or
          given directly or indirectly for soliciting the Exchange.

               3.15 Reliance.  The Subscriber understands and acknowledges
          that the Company is relying upon all of the
          representations, warranties, covenants, understandings,
          acknowledgments and agreements contained in this
          Agreement in determining whether to accept this
          subscription and to sell and issue the Series 13
          Preferred to the Subscriber.

               3.16 Accuracy or Representations and Warranties.  All of the
          representations, warranties, understandings and
          acknowledgments that Subscriber has made herein are true
          and correct in all material respects as of the date of
          execution hereof.  The Subscriber will perform and comply
          fully in all material respects with all covenants and
          agreements set forth herein, and the Subscriber covenants
          and agrees that until the acceptance of this Agreement by
          the Company, the Subscriber shall inform the Company
          immediately in writing of any changes in any of the
          representations or warranties provided or contained
          herein.

               3.17 Indemnity.  The Subscriber hereby agrees to indemnify and
          hold harmless the Company, and the Company's successors
          and assigns, from, against and in all respects of any
          demands, claims, actions or causes of action,
          assessments, liabilities, losses, costs, damages,
          penalties, charges, fines or expenses (including, without
          limitation, interest, penalties, and attorney and
          accountants' fees, disbursements and expenses), arising
          out of or relating to any breach by Subscriber of any
          representations, warranty, covenant or agreement made by
          Subscriber in this Agreement.  Such right to
          indemnification shall be in addition to any and all other
          rights of the Company under this Agreement or otherwise,
          at law or in equity.

               3.18 Survival.  The Subscriber expressly acknowledges and
          agrees that all of its representations, warranties,
          agreements and covenants set forth in this Agreement
          shall be of the essence hereof and shall survive the

                               -9-


          execution, delivery and Closing of this Agreement, the
          sale, purchase, and conversion, if any, of the Series 13
          Preferred, the sale of the Conversion Shares, the
          exercise of the Series 10 Warrants, and the sale of the
          Warrant Shares.

4.   Representations, Warranties and Covenants of the Company.  In
order to induce Subscriber to enter into this Agreement and to
exchange the Series 10 Preferred for the Series 13 Preferred, the
Company hereby represents, warrants and covenants to Subscriber as
follows:

     4.1  Organization, Authority, Qualification.  The Company is
          a corporation duly incorporated, validly existing and in
          good standing under the laws of the State of Delaware.
          The Company has full corporate power and authority to own
          and operate its properties and assets and to conduct and
          carry on its business as it is now being conducted and
          operated.

     4.2  Authorization.  The Company has full power and authority
          to execute and deliver this Agreement and to perform its
          obligations under and consummate the transactions
          contemplated by this Agreement.  Upon the execution of
          this Agreement by the Company and delivery of the
          Securities, this Agreement shall have been duly and
          validly executed and delivered by the Company and shall
          constitute the legal, valid and binding obligation of the
          Company, enforceable against the Company in accordance
          with its terms.

     4.3  No Commission.  The Company agrees and acknowledges that
          no commission or other remuneration is being paid or
          given directly or indirectly for soliciting the Exchange.

     4.4  Ownership of, and Title to, Securities.  The Series 13
          Preferred to be exchanged for the Series 10 Preferred by
          the Subscriber are, and all Conversion Shares, when
          issued, will be, duly authorized, validly issued, fully
          paid and nonassessable shares of the capital stock of the
          Company, free of personal liability.  Upon consummation
          of the exchange of the Series 13 Preferred (and upon the
          conversion of the Series 13 Preferred, in whole or in
          part) pursuant to this Agreement, the Subscriber will own
          and acquire title to the Series 13 Preferred (and the
          Conversion Shares, as the case may be) free and clear of
          any and all proxies, voting trusts, pledges, options,
          restrictions, or other legal or equitable encumbrance of
          any nature whatsoever (other than the restrictions on
          transfer due to Securities Laws or as otherwise provided
          for in this Agreement or the Series 13 Preferred
          Certificate of Designations).

     4.5  Exemption from Registration.  The offer and exchange of
          securities with the Subscriber in accordance with the
          terms and provisions of this Agreement is being affected
          in accordance with the Securities Act, pursuant to an
          exchange offer exemption to the registration provision of
          the Securities Act pursuant to Section 3(a)(9) thereunder
          and to a private placement exemption to the registration

                               -10-


          provisions of the Act pursuant to Section 4(2) of such
          Act and/or Regulation D promulgated under the Securities
          Act, based on the representations, warranties and
          covenants made by the Subscriber contained in this
          Agreement.

5.   Registration Rights.  In order to induce the Subscriber to
enter into this Agreement and exchange the Series 10 Preferred for
the Series 13 Preferred, the Company hereby covenants and agrees to
grant to the Subscriber the registration rights with respect to the
Conversion Shares and the shares of Common Stock which may issue as
dividends on the Series 13 Preferred, as set forth in Section 10 of
the Subscription Agreement regarding the shares of Common Stock
issuable upon conversion of the Series 13 Preferred and as
dividends thereon.  The registration rights as set forth in Section
10 of the Subscription Agreement regarding the shares of Common
Stock issuable upon exercise of the Series 10 Warrants are not
changed by this Agreement.

6.   Indemnification.

     6.1  By the Company.  Subject to the terms of this Section 6,
          the Company will indemnify and hold harmless the
          Subscriber, its directors and officers, and any
          underwriter (as defined in the Securities Act) for the
          Subscriber and each person, if any, who controls the
          Subscriber or such underwriter within the meaning of the
          Act, from and against, and will reimburse the Subscriber
          and each such underwriter and controlling person with
          respect to, any and all loss, damage, liability, cost and
          expense to which such holder or any such underwriter or
          controlling person may become subject under the Act or
          otherwise, insofar as such losses, damages, liabilities,
          costs or expenses are caused by any untrue statement or
          alleged untrue statement of any material fact contained
          in the Registration Statement filed with the SEC in
          connection with the Conversion Shares, any prospectus
          contained therein or any amendment or supplement thereto,
          or arise out of, or are based upon, the omission or
          alleged omission to state therein a material fact
          required to be stated therein or necessary to make the
          statements therein, in light of the circumstances in
          which they were made not misleading; provided, however,
          that the Company will not be liable in any such case to
          the extent that any such loss, damage, liability, cost or
          expense arises out of, or is based upon, an untrue
          statement or alleged untrue statement or omission or
          alleged omission so made in conformity with information
          furnished by the Subscriber, such underwriter or such
          controlling person in writing specifically for use in the
          preparation thereof.

     6.2  By the Subscriber.  Subject to the terms of this Section
          6, the Subscriber will indemnify and hold harmless the
          Company, its directors and officers, any controlling
          person and any underwriter from and against, and will
          reimburse the Company, its directors and officers, any
          controlling person and any underwriter with respect to,
          any and all loss, damage, liability, cost or expense to
          which the Company or any controlling person and/or any
          underwriter may become subject under the Securities Act
          or otherwise, insofar as such losses, damages,

                               -11-


          liabilities, costs or expenses are caused by any untrue
          statement or alleged untrue statement of any material
          fact contained in a Registration Statement filed with the
          SEC in connection to the Conversion Shares, any
          prospectus contained therein or any amendment or
          supplement thereto, or arise out of, or are based upon,
          the omission or alleged omission to state therein a
          material fact required to be stated therein or necessary
          to make the statements therein, in light of the
          circumstances in which they were made, not misleading, in
          each case to the extent, but only to the extent, that
          such untrue statement or alleged untrue statement or
          omission or alleged omission was so made in reliance
          upon, and in strict conformity with, written information
          furnished by, or on behalf of, the Subscriber
          specifically for use in the preparation thereof.

     6.3  Procedure.  Promptly after receipt by an indemnified
          party pursuant to the provisions of Section 6.1 or 6.2 of
          notice of the commencement of any action involving the
          subject matter of the foregoing indemnity provisions,
          such indemnified party will, if a claim thereof is to be
          made against the indemnifying party pursuant to the
          provisions of Section 6.1 or 6.2, promptly notify the
          indemnifying party of the commencement thereof; but the
          omission to so notify the indemnifying party will not
          relieve the indemnifying party from any liability which
          it may have to any indemnified party otherwise than
          hereunder.  In case such action is brought against any
          indemnified party and the indemnified party notifies the
          indemnifying party of the commencement thereof, the
          indemnifying party shall have the right to participate
          in, and, to the extent that it may wish, assume the
          defense thereof; or, if there is a conflict of interest
          which would prevent counsel for the indemnifying party
          from also representing the indemnified party, the
          indemnified parties have the right to select only one (1)
          separate counsel to participate in the defense of such
          action on behalf of all such indemnified parties.  After
          notice from the indemnifying parties to such indemnified
          party of the indemnifying parties' election so to assume
          the defense thereof, the indemnifying parties will not be
          liable to such indemnified parties pursuant to the
          provisions of said Section 6.1 or 6.2 for any legal or
          other expense subsequently incurred by such indemnified
          parties in connection with the defense thereof, other
          than reasonable costs of investigation, unless (a) the
          indemnified parties shall have employed counsel in
          accordance with the provisions of the preceding sentence;
          (b) the indemnifying parties shall not have employed
          counsel satisfactory to the indemnified parties to
          represent the indemnified parties within a reasonable
          time after the notice of the commencement of the action
          or (c) the indemnifying party has authorized the
          employment of counsel for the indemnified party at the
          expense of the indemnifying parties.

7.   Securities Legends and Notices.  Subscriber represents and
warrants that it has read, considered and understood the following
legends, and agrees that such legends, substantially in the form
and substance set forth below, shall be placed on all of the
certificates representing the Series 13 Preferred:

                               -12-


     Series 13 Preferred Legends

     NEITHER THIS PREFERRED STOCK NOR ANY SHARES OF COMMON
     STOCK ISSUABLE UPON THE CONVERSION OF THIS PREFERRED
     STOCK HAVE BEEN REGISTERED UNDER THE SECURITIES ACT OF
     1933, AS AMENDED (THE "SECURITIES ACT") OR QUALIFIED
     UNDER APPLICABLE STATE SECURITIES LAWS.  THIS PREFERRED
     STOCK AND THE COMMON STOCK ISSUABLE UPON CONVERSION OF
     THIS PREFERRED STOCK MAY NOT BE OFFERED, SOLD, PLEDGED,
     HYPOTHECATED OR OTHERWISE TRANSFERRED IN THE ABSENCE OF
     AN EFFECTIVE REGISTRATION STATEMENT AND QUALIFICATION IN
     EFFECT WITH RESPECT THERETO UNDER THE SECURITIES ACT AND
     UNDER ANY APPLICABLE STATE SECURITIES LAW OR WITHOUT THE
     PRIOR WRITTEN CONSENT OF PERMA-FIX ENVIRONMENTAL
     SERVICES, INC. AND AN OPINION OF PERMA-FIX ENVIRONMENTAL
     SERVICES, INC.'S COUNSEL, OR AN OPINION FROM COUNSEL FOR
     THE HOLDER HEREOF, WHICH OPINION IS SATISFACTORY TO THE
     COMPANY, THAT SUCH REGISTRATION AND QUALIFICATION IS NOT
     REQUIRED UNDER APPLICABLE FEDERAL AND STATE SECURITIES
     LAWS OR AN EXEMPTION THEREFROM.

     NOTWITHSTANDING THE FOREGOING, THE SHARES OF COMMON STOCK
     ISSUABLE UPON CONVERSION ARE ALSO SUBJECT TO THE
     REGISTRATION RIGHTS SET FORTH IN THAT CERTAIN
     SUBSCRIPTION AGREEMENT BY AND BETWEEN THE HOLDER HEREOF
     AND THE COMPANY, DATED AS OF JUNE 30, 1998, A COPY OF
     WHICH IS ON FILE AT THE COMPANY'S PRINCIPAL EXECUTIVE
     OFFICE.

     Conversion Shares Legends

     THE SHARES OF COMMON STOCK REPRESENTED BY THIS
     CERTIFICATE HAVE NOT BEEN REGISTERED UNDER THE SECURITIES
     ACT OF 1933, AS AMENDED (THE "SECURITIES ACT") OR
     QUALIFIED UNDER APPLICABLE STATE SECURITIES LAWS.  THIS
     COMMON STOCK MAY NOT BE OFFERED, SOLD, PLEDGED,
     HYPOTHECATED OR OTHERWISE TRANSFERRED IN THE ABSENCE OF
     AN EFFECTIVE REGISTRATION STATEMENT AND QUALIFICATION IN
     EFFECT WITH RESPECT THERETO UNDER THE SECURITIES ACT AND
     UNDER ANY APPLICABLE STATE SECURITIES LAW OR WITHOUT THE
     PRIOR WRITTEN CONSENT OF PERMA-FIX ENVIRONMENTAL
     SERVICES, INC. AND AN OPINION OF PERMA-FIX ENVIRONMENTAL
     SERVICES, INC.'S COUNSEL, OR AN OPINION FROM COUNSEL FOR
     THE HOLDER HEREOF, WHICH OPINION IS SATISFACTORY TO THE

                               -13-



    COMPANY, THAT SUCH REGISTRATION AND QUALIFICATION IS NOT
     REQUIRED UNDER APPLICABLE FEDERAL AND STATE SECURITIES
     LAWS OR AN EXEMPTION THEREFROM.

     NOTWITHSTANDING THE FOREGOING, THESE SHARES OF COMMON
     STOCK ARE ALSO SUBJECT TO THE REGISTRATION RIGHTS SET
     FORTH IN THAT CERTAIN SUBSCRIPTION AGREEMENT BY AND
     BETWEEN THE HOLDER HEREOF AND THE COMPANY, DATED AS OF
     JUNE 30, 1998, A COPY OF WHICH IS ON FILE AT THE
     COMPANY'S PRINCIPAL EXECUTIVE OFFICE.

8.   Miscellaneous.

     8.1  Assignment and Power of Attorney.  For purposes of
          affecting the exchange of the Series 10 Preferred in
          accordance with the terms of this Agreement at the
          Closing, the Subscriber does hereby assign all of its
          right, title and interest in and to the Series 10
          Preferred to the Company and irrevocably makes,
          constitutes and appoints the Company as the true and
          lawful agents and attorneys-in-fact of the Subscriber
          ("Attorney-In-Fact") with full power and authority
          (except as provided below) to act hereunder individually,
          or through duly appointed successor attorneys-in-fact, in
          its sole discretion, all as hereinafter provided, in the
          name of, for and on behalf of the Subscriber, as fully as
          could the Subscriber if present and acting in person,
          with respect to all matters in connection with the
          transfer of the Series 10 Preferred.

     8.2  Amendment; Waiver.  Neither this Agreement nor the
          Warrants shall be changed, modified or amended in any
          respect except by the mutual written agreement of the
          parties hereto.  Any provision of this Agreement or the
          Warrants may be waived in writing by the party which is
          entitled to the benefits thereof.  No waiver of any
          provision of this Agreement or the Series 10 Warrants
          shall be deemed to, or shall constitute a waiver of, any
          other provision hereof or thereof (whether or not
          similar), nor shall nay such waiver constitute a
          continuing waiver.

     8.3  Binding Effect; Assignment.  Neither this Agreement nor
          the Series 10 Warrants, or any rights or obligations
          hereunder or thereunder, are assignable by the
          Subscriber.

     8.4  Governing Law; Litigation Costs.  This Agreement and its
          validity, construction and performance shall be governed
          in all respects by the internal laws of the State of
          Delaware without giving effect to such State's conflicts
          of laws provisions.  Each of the Company and the
          Subscriber expressly and irrevocably consent to the
          jurisdiction and venue of the federal courts located in
          Wilmington, Delaware.  Each of the parties agrees that in
          the event either party brings an action to enforce any of
          the provisions of this Agreement or to recovery for an
          alleged breach of any of the provisions of this
          Agreement, each party shall be responsible for its own
          legal costs and disbursements during the pendency of any
          such action; provided, however, that after any such

                               -14-



         action has been reduced to a final, unappealable
          judgment, the prevailing party shall be entitled to
          recover from the other party all reasonable, documented
          attorneys' fees and disbursements and court costs from
          the other party.

     8.5  Severability.  Any term or provisions of this Agreement
          or the Series 10 Warrants which is prohibited or
          unenforceable in any jurisdiction shall, as to such
          jurisdiction only, be ineffective only to the extent of
          such prohibition or unenforceability without invalidating
          the remaining provisions hereof or thereof affecting the
          validity or enforceability of such provision in any other
          jurisdiction.

     8.6  Headings.  The captions, headings and titles preceding
          the text of each or any Section, subsection or paragraph
          hereof are for convenience of reference only and shall
          not affect the construction, meaning or interpretation of
          this Agreement or the Warrants or any term or provisions
          hereof or thereof.

     8.7  Counterparts.  This Agreement may be executed in one or
          more original or facsimile counterparts, each of which
          shall be deemed an original and all of which shall be
          considered one and the same agreement, binding on all of
          the parties hereto, notwithstanding that all parties are
          not signatories to the same counterpart.  Upon delivery
          of an executed counterpart by the undersigned Subscriber
          to the Company, which in turn is executed and delivered
          by the Company, this Agreement shall be binding as one
          original agreement between Subscriber and the Company.

     8.8  Transfer Taxes.  Each party hereto shall pay all such
          sales, transfer, use, gross receipts, registration and
          similar taxes arising out of, or in connection with, the
          transactions contemplated by this Agreement
          (collectively, the "Transfer Taxes") as are payable by
          such party under applicable law, and the Company shall
          pay the cost of any documentary stock transfer stamps, if
          any, to be affixed to the certificates representing the
          Shares to be sold.

     8.9  Entire Agreement.  This Agreement, along with the Series
          10 Warrants and the Series 13 Preferred Certificate of
          Designations, merges and supersedes any and all prior
          agreements, understandings, discussions, assurances,
          promises, representations or warranties among the parties
          with respect to the subject matter hereof, and contains
          the entire agreement among the parties with respect to
          the subject matter set forth herein and therein.

     8.10 Authority; Enforceability.  The Subscriber is duly
          authorized to enter into this Agreement and to perform
          all of its obligations hereunder.  Upon the execution and
          delivery of this Agreement by the Subscriber, this
          Agreement shall be enforceable against the Subscriber in
          accordance with its terms.

                               -15-


     8.11 Notices.  Except as otherwise specified herein to the
          contrary, all notices, requests, demands and other
          communications required or desired to be given hereunder
          shall only be effective if given in writing, by hand or
          by fax, by certified or registered mail, return receipt
          requested, postage prepaid, or by U. S. Express Mail
          service, or by private overnight mail service (e.g.,
          Federal Express).  Any such notice shall be deemed to
          have been given (i) on the business day actually received
          if given by hand or by fax, (ii) on the business day
          immediately subsequent to mailing, if sent by U.S.
          Express Mail service or private overnight mail service,
          or (iii) five (5) business days following the mailing
          thereof, if mailed by certified or registered mail,
          postage prepaid, return receipt requested, and all such
          notices shall be sent to the following addresses (or to
          such other address or addresses as a party may have
          advised the other in the manner provided in this Section
          8.11:

          If to the Company:  Dr. Louis F. Centofanti
                              Perma-Fix Environmental
                              Services, Inc.
                              1940 Northwest 67th Place
                              Gainesville, Florida  32653
                              Fax No.: (352) 373-0040

          with copies         Irwin H. Steinhorn, Esquire
          simultaneously      Conner & Winters
          by like means to:   One Leadership Square, Suite 1700
                              211 North Robinson
                              Oklahoma City, Oklahoma  73102
                              Fax No.: (405) 232-2695


          If to the           Herbert Strauss
          Subscriber:         RBB Bank Aktiengesellschaft
                              Burgring 16, 8010 Graz, Austria
                              Fax No.: 011-43-316-8072 ext. 392

     8.12 No Third Party Beneficiaries.  This Agreement and the
          rights, benefits, privileges, interests, duties and
          obligations contained or referred to herein shall be
          solely for the benefit of the parties hereto and no third
          party shall have any rights or benefits hereunder as a
          third party beneficiary or otherwise hereunder.

     8.13 Public Announcements.  Neither Subscriber nor any
          officer, director, stockholder, employee, affiliate or
          affiliated person or entity of Subscriber, shall make or
          issue any press releases or otherwise make any public

                               -16-


          statements or make any disclosures to any third person or
          entity with respect to the transactions contemplated
          herein and will not make or issue any press releases or
          otherwise make any public statements of any nature
          whatsoever with respect to the Company without the
          express prior approval of the Company.

     8.14 Conflicts with Subscription Agreement.  In the event of
          a conflict between the terms of the Subscription
          Agreement and the terms of this Agreement, this Agreement
          shall control in all respects.

     IN WITNESS WHEREOF, the Company and the undersigned Subscriber
have each duly executed this Agreement on the 15th day of July,
1999.

                                   PERMA-FIX ENVIRONMENTAL
                                   SERVICES, INC.


                                   By /s/ Louis Centofanti
                                     ___________________________
                                     Dr. Louis F. Centofanti
                                     Chief Executive Officer

                                   RBB BANK AKTIENGESELLSCHAFT


                                   By  /s/ Herbert Strauss
                                     ___________________________
                                     Herbert Strauss
                                     Headtrader









                               -17-