State of Delaware                         PAGE 1

                        Office of the Secretary of State

                        --------------------------------

      I, EDWARD J. FREEL, SECRETARY OF STATE OF THE STATE OF DELAWARE, DO HEREBY
CERTIFY THE ATTACHED IS A TRUE AND CORRECT COPY OF THE CERTIFICATE OF AMENDMENT
OF "CONVERSION TECHNOLOGIES INTERNATIONAL, INC.", FILED IN THIS OFFICE ON THE
SECOND DAY OF APRIL, A.D. 1998, AT 9 O'CLOCK A.M.


                                             /s/ Edward J. Freel
                                             -----------------------------------
                                             Edward J. Freel, Secretary of State
                                    [SEAL]
                                             AUTHENTICATION:     9008800
                                                       DATE:     04-02-98
<PAGE>

                            CERTIFICATE OF AMENDMENT

                                     TO THE

                      RESTATED CERTIFICATE OF INCORPORATION
                                       OF

                   CONVERSION TECHNOLOGIES INTERNATIONAL, INC.

      Pursuant to Section 242 of the Delaware General Corporation Law, the
undersigned Conversion Technologies International, Inc. (the "Corporation")
executes this Certificate of Amendment to its Restated Certificate of
Incorporation.

      I. The first paragraph of ARTICLE FOURTH of the Corporation's Restated
Certificate of Incorporation is amended to provide in its entirety:

            The total number of shares of all classes of stock which the
      Corporation shall have authority to issue is 65,000,000 shares, consisting
      of (a) 50,000,000 shares of common stock, $.00025 par value (the "Common
      Stock") and (b) 15,000,000 shares of preferred stock, $.001 par value (the
      "Preferred Stock"). Of the 15,000,000 authorized shares of Preferred
      Stock, (i) 2,958,000 shares were designated as Series A Preferred Stock,
      having the terms set forth herein, all of which shares were converted into
      Common Stock upon consummation of the Corporation's initial public
      offering of Common Stock, (ii) 880,000 shares have been designated as a
      new Series A Convertible Preferred Stock pursuant to a Certificate of
      Designation, having the terms set forth therein, and (iii) 11,162,000
      shares remain authorized but undesignated shares of Preferred Stock,
      subject to designation and issuance as hereinafter provided.

      II. The foregoing amendment was duly adopted by the stockholders of the
Corporation in accordance with Section 242 of the Delaware General Corporation
Law.

      IN WITNESS WHEREOF, this Certificate of Amendment has been executed as of
the 1st day of April, 1998.

                                              CONVERSION TECHNOLOGIES
                                                INTERNATIONAL, INC.


                                              By: /s/ William L. Amt
                                                  ------------------------------
                                                  William L. Amt, President and
                                                  Chief Executive Officer

ATTEST:


By: /s/ William Gary Jellum
    ------------------------------
    William Gary Jellum, Secretary