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                                                                 EXHIBIT 4.8





















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                             STOCK OPTION AGREEMENT
                             ----------------------


         STOCK OPTION AGREEMENT, dated as of February 20, 1998 (the
"Agreement"), among Harsco Corporation, a Delaware corporation ("Parent"),
H-Chemi Acquisition Corp., a Pennsylvania corporation and a direct, wholly-owned
subsidiary of Parent ("Subsidiary") and Chemi-Trol Chemical Co., an Ohio
corporation (the "Company").

         WHEREAS, Parent, Subsidiary and the Company propose to enter into an
Agreement and Plan of Merger dated the date hereof (the "Merger Agreement"),
which provides, among other things, that upon the terms and subject to the
conditions thereof, Parent will acquire all outstanding shares of Common Stock
of the Company (the "Company Common Stock"), Subsidiary will be merged with the
Company pursuant to the merger contemplated in the Merger Agreement (the
"Merger") and, thereafter, the Company will be a wholly-owned subsidiary of
Parent; and

         WHEREAS, as a condition to the willingness of Parent and Subsidiary to
enter into the Merger Agreement, Parent and Subsidiary have requested that the
Company agree, and in order to induce Parent and Subsidiary to enter into the
Merger Agreement the Company has agreed, to grant Subsidiary an option to
purchase up to 190,468 shares of Company Common Stock, all in accordance with
the terms of this Agreement.

         NOW, THEREFORE, in consideration of the foregoing and the mutual
covenants and agreements set forth herein and in the Merger Agreement, and
intending to be legally bound hereby, the parties hereto agree as follows:

         1. GRANT OF STOCK OPTION. The Company hereby grants to Subsidiary an
irrevocable option (the "Option") to purchase up to 190,468 shares of Company
Common Stock (the "Option Shares") at a purchase price of $13.75 per Option
Share (the "Purchase Price").

         2. EXERCISE OF OPTION.

                  (a) Subject to the conditions set forth in paragraph 3 hereof,
         the Option may be exercised by Subsidiary, in whole or in part, at any
         time or from time to time after the date hereof and prior to the
         earlier to occur of (a) the Effective Time of the Merger or (b) upon a
         Purchase Event (as defined below), the date six months following such
         Purchase Event, provided that if an Exercise Notice (as hereinafter
         defined) had been given on or before the expiration of such six-month
         period and if the Option cannot be exercised on such day because of any
         injunction, order or similar restraint issued by a court of competent
         jurisdiction, the Option shall expire on the tenth business day after
         such injunction, order or restraint shall have been dismissed, been
         withdrawn or become




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         permanent and no longer subject to appeal, as the case may be (the
         "Termination Date"). In the event Subsidiary wishes to exercise the
         Option, Subsidiary shall send a written notice (an "Exercise Notice")
         to the Company specifying the total number of Option Shares it wishes
         to purchase. Each closing of a purchase of Option Shares (a "Stock
         Option Closing") shall take place at the executive offices of the
         Company at the address referred to in Section 13(d) hereof, on a date
         and at a time designated by Subsidiary in its Exercise Notice (which
         date and time may be as early as one day after the Exercise Notice or
         earlier if reasonably practicable).

                  (b) As used in this Agreement, a "Purchase Event" shall mean
         any of the following events:

                           (1) any person (other than Parent or any subsidiary
                  of Parent) shall have commenced (as such term is defined in
                  Rule 14d-2 under the Securities Exchange Act of 1934, as
                  amended (the "Exchange Act")), a tender offer or exchange
                  offer to purchase Company Common Stock such that, upon
                  consummation of such offer, such person could own or control
                  20 percent or more of the outstanding Company Common Stock,
                  and such person has obtained approval of shareholders of the
                  Company in accordance with Section 1701.831 of the Ohio
                  Revised Code in respect of such control share acquisition;

                           (2) the Company shall have authorized, recommended,
                  proposed or announced an intention to authorize, recommend or
                  propose, or entered into, an agreement with any person (other
                  than Parent or any subsidiary of Parent) to (A) merge or
                  consolidate with the Company or enter into any similar
                  transaction with such person, (B) sell, lease or otherwise
                  dispose of all or substantially all of the assets of the
                  Company to such person, or (C) sell or otherwise dispose of
                  (including by way of merger, consolidation, share exchange or
                  similar transaction) securities representing 20 percent or
                  more of the voting power of the Company, and the same shall
                  have been scheduled by the Company to close within 365
                  calendar days following the date of termination of the Merger
                  Agreement;

                           (3) any person (other than Parent or any subsidiary
                  of Parent) shall have acquired beneficial ownership (as such
                  term is defined in Rule 13d-3 under the Exchange Act) or the
                  right to acquire beneficial ownership of, or a new group has
                  been formed which beneficially owns, 20 percent or more of the
                  outstanding Company Common Stock, and such person has obtained
                  approval of shareholders of the Company in accordance with
                  Section 1701.831 of the Ohio Revised Code in respect of such
                  control share acquisition; or

                           (4) the shareholders of the Company shall have
                  disapproved the Merger after any person (other than Parent or
                  any subsidiary of Parent) shall have publicly announced a
                  proposal to acquire the Company by merger, consolidation,


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                  purchase of all or substantially all of its assets or any
                  other similar transaction, and the same shall have been
                  scheduled by the Company to close within 365 calendar days
                  following the date of termination of the Merger Agreement.

As used in this Agreement, "person" shall have the meanings specified in
Sections 3(a)(9) and 13(d)(3) of the Exchange Act.

         (c) Notwithstanding anything herein to the contrary, in the event that
Parent receives payment in full of the $1.7 million termination fee set forth in
Section 8.02(b) of the Merger Agreement, the number of Option Shares that
Subsidiary shall have the option to purchase hereunder shall be reduced from
190,468 to 95,234.

         3. STOCK OPTION CLOSINGS. At each Stock Option Closing, the Company
will deliver to Subsidiary a certificate or certificates representing the number
of Option Shares being purchased upon exercise of the Option in the
denominations designated by Subsidiary in its Exercise Notice, and Subsidiary
will purchase such Option Shares from the Company at the Purchase Price per
share. Any payment made by Subsidiary to the Company pursuant to this Section 3
shall be paid in New York Clearing House funds by wire transfer or certified or
official bank check or checks payable to the order of the Company in an amount
equal to the aggregate Purchase Price of the Option Shares purchased at the
Stock Option Closing.

         4. OPTION SHARE APPRECIATION RIGHT. If a Purchase Event shall occur at
any time prior to the expiration of the Stock Option, at Subsidiary's request
the Company shall promptly pay to Subsidiary in New York Clearing House funds by
wire transfer or certified or official bank check payable to the order of
Subsidiary an amount equal to the product of (a) the excess, if any of (i) the
greater of (A) the highest price paid or proposed to be paid in connection with
such Purchase Event for any shares of Company Common Stock and (B) the aggregate
consideration paid or proposed to be paid in connection with such Purchase Event
divided by the number of shares of Company Common Stock then outstanding (the
value of any consideration other than cash to be determined, in the case of
consideration with a readily ascertainable market value, by reference to such
market value and, in the case of any consideration other than cash, by agreement
in good faith between Subsidiary and the Company) over (ii) the Purchase Price,
as adjusted pursuant to Section 7, multiplied by (b) the total number of Option
Shares as to which the Option has not theretofore been exercised, as adjusted
pursuant to Section 7. Such payment shall extinguish all other rights of Parent
and Subsidiary under this Agreement, but shall not affect the rights of Parent
and Subsidiary under the Merger Agreement or otherwise.

         5. REPRESENTATIONS AND WARRANTIES OF THE COMPANY. The Company hereby
represents and warrants to Parent and Subsidiary as follows:

                  (a) AUTHORITY RELATIVE TO THIS AGREEMENT. The Company has full
         corporate power and authority to execute and deliver this Agreement and
         to consummate the transactions contemplated hereby. The execution and
         delivery of this Agreement and the


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         consummation of the transactions contemplated hereby have been duly and
         validly authorized by the Board of Directors of the Company and no
         other corporate proceedings on the part of the Company are necessary to
         authorize this Agreement or to consummate the transactions so
         contemplated. This Agreement has been duly and validly executed and
         delivered by the Company and, assuming this Agreement has been duly
         executed and delivered by Parent and Subsidiary, this Agreement
         constitutes a valid and binding agreement of the Company enforceable in
         accordance with its terms except as enforcement may be limited by
         bankruptcy, insolvency or other similar laws affecting the enforcement
         of creditors' rights generally and except that the availability of
         equitable remedies, including specific performance, is subject to the
         discretion of the court before which any proceeding therefor may be
         brought.

                  (b) AUTHORITY TO ISSUE SHARES. The Company has taken all
         necessary corporate action to authorize and reserve and to permit it to
         issue, and at all times from the date hereof through the Termination
         Date will have reserved, all of the Option Shares issuable pursuant to
         this Agreement, all of which, upon their issuance and delivery in
         accordance with the terms of this Agreement, will be duly authorized,
         validly issued, fully paid and nonassessable, and will be delivered
         free and clear of all claims, liens, encumbrances and security
         interests of any nature whatsoever and not subject to any preemptive
         rights.

                  (c) NO CONFLICT. The execution and delivery of this Agreement
         by the Company do not, and the performance of this Agreement by the
         Company will not, (i) require the consent, waiver, approval, license or
         authorization of or any filing with any person or public authority,
         (ii) violate the Articles of Incorporation or Regulations or other
         organizational or governance documents of the Company, (iii) with or
         without the giving of notice or the lapse of time, or both, conflict
         with or result in a breach of any terms or provisions of, or constitute
         a default or give rise to a right of acceleration under, or result in
         the creation or imposition of any lien, charge or encumbrance upon any
         property or assets of the Company under, any indenture, mortgage,
         agreement or other instrument to which the Company is a party or by
         which any of its property is bound or (iv) violate any existing
         applicable law, rule, regulation, judgment, order or decree of any
         governmental instrumentality or court having jurisdiction over the
         Company or any of its property. The execution and performance of this
         Agreement and the Merger Agreement do not constitute a "1704.
         Transaction" as that term is used in the Ohio General Corporation Law.

         6. REPRESENTATIONS AND WARRANTIES OF PARENT. Each of Parent and
Subsidiary hereby represents and warrants to the Company as follows:

                  (a) Each of Parent and Subsidiary has full corporate power and
         authority to execute and deliver this Agreement and to consummate the
         transactions contemplated hereby. The execution and delivery of this
         Agreement and the consummation of the transactions contemplated hereby
         have been duly and validly authorized by the Boards of


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         Directors of Parent and Subsidiary and no other corporate proceedings
         on the part of Parent or Subsidiary are necessary to authorize this
         Agreement or to consummate the transactions so contemplated. This
         Agreement has been duly and validly executed and delivered by each of
         Parent and Subsidiary and, assuming this Agreement has been duly
         executed and delivered by the Company, this Agreement constitutes a
         valid and binding agreement of each of Parent and Subsidiary
         enforceable in accordance with its terms except as enforcement may be
         limited by bankruptcy, insolvency or other similar laws affecting the
         enforcement of creditors' rights generally and except that the
         availability of equitable remedies, including specific performance, is
         subject to the discretion of the court before which any proceeding
         therefor may be brought.

                  (b) NO CONFLICT. The execution and delivery of this Agreement
         do not, and the performance of this Agreement by Parent and Subsidiary
         will not, (i) require the consent, waiver, approval, license or
         authorization of or any filing with any person or public authority,
         (ii) violate the charter documents or By-Laws or other organizational
         or governance documents of Parent or Subsidiary, (iii) with or without
         the giving of notice or the lapse of time, or both, conflict with or
         result in a breach of any terms or provisions of, or constitute a
         default or give rise to a right of acceleration under, or result in the
         creation or imposition of any lien, charge or encumbrance upon any
         property or assets of Parent or Subsidiary under, any indenture,
         mortgage, agreement or other instrument to which Parent or Subsidiary
         is a party or by which any of their respective property is bound or
         (iv) violate any existing applicable law, rule, regulation, judgment,
         order or decree of any governmental instrumentality or court having
         jurisdiction over Parent or Subsidiary or any of their respective
         property.

                  (c) INVESTMENT INTENT. Each of Parent and Subsidiary hereby
         represents and warrants to the Company that it will acquire the Option
         Shares for investment purposes only and not with a view to any resale
         or distribution thereof, and will not sell any Option Shares purchased
         pursuant to the Option except in compliance with the Securities Act of
         1933, as amended (the "Securities Act").

         7. ADJUSTMENT UPON CHANGES IN CAPITALIZATION. In the event of any
change in the number of issued and outstanding shares of Company Common Stock by
reason of any stock dividend, split-up, merger, recapitalization, combination,
conversion, exchange of shares or the like, or any other change in the corporate
or capital structure of the Company which would have the effect of diluting
Subsidiary's rights hereunder, the number and kind of Option Shares and the
consideration payable in respect of such Option Shares shall be appropriately
adjusted to restore to Subsidiary its rights hereunder; PROVIDED, HOWEVER, that
nothing in this Agreement shall be construed as permitting the Company to take
any action or enter into any transaction prohibited by the Merger Agreement.

         8. LISTING. The Company will use its best efforts to qualify the Option
Shares for trading on NASDAQ as promptly as practicable following the date of
this Agreement.


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         9. FURTHER ASSURANCES. The Company, Parent and Subsidiary will execute
and deliver all such further documents and instruments and take all such further
action as may be necessary in order to consummate the transactions contemplated
hereby.

         10. SPECIFIC PERFORMANCE. The parties hereto acknowledge that damages
would be an inadequate remedy for a breach of this Agreement and that the
obligations of the parties hereto shall be specifically enforceable.

         11. EXPENSES. Except as otherwise explicitly stated herein and in the
Merger Agreement, all costs and expenses incurred in connection with the
transactions contemplated by this Agreement shall be paid by the party incurring
such expenses.

         12. MISCELLANEOUS.

                  (a) ENTIRE AGREEMENT. This Agreement and the Merger Agreement
         constitute the entire agreement between the parties with respect to the
         subject matter hereof and supersede all other prior agreements and
         understandings, both written and oral, among the parties or any of them
         with respect to the subject matter hereof.

                  (b) ASSIGNMENT. This Agreement shall not be assigned by
         operation of law or otherwise, PROVIDED that Subsidiary may assign its
         rights and obligations to Parent or any wholly-owned direct or indirect
         subsidiary of Parent or the parent of Parent, but no such assignment
         shall relieve Subsidiary of its obligations hereunder if such assignee
         does not perform such obligations.

                  (c) VALIDITY. The invalidity or unenforceability of any
         provision of this Agreement shall not affect the validity or
         enforceability of any other provisions of this Agreement, which shall
         remain in full force and effect.

                  (d) NOTICES. All notices, requests, claims, demands and other
         communications hereunder shall be deemed to have been duly given when
         delivered in person, by cable, telegram or telex, or by registered or
         certified mail (postage prepaid, return receipt requested) to the
         respective parties at their addresses as specified in the Merger
         Agreement.

                  (e) GOVERNING LAW. This Agreement shall be governed in all
         respects, including validity, interpretation and effect, by the laws of
         the Commonwealth of Pennsylvania, applicable to contracts made and to
         be performed in that state.

                  (f) DESCRIPTIVE HEADINGS; DEFINITIONS. The descriptive
         headings herein are inserted for convenience of reference only and are
         not intended to be part of or to affect the meaning or interpretation
         of this Agreement. All capitalized terms used herein but not defined
         herein shall have the meaning ascribed to them in the Merger Agreement.


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                  (g) PARTIES IN INTEREST. This Agreement shall be binding upon
         and inure solely to the benefit of each party hereto, and nothing in
         this Agreement, express or implied, is intended to confer upon any
         other person any rights or remedies of any nature whatsoever under or
         by reason of this Agreement.

                  (h) COUNTERPARTS. This Agreement may be executed in two or
         more counterparts, each of which shall be deemed to be an original, but
         all of which shall constitute one and the same agreement.

         IN WITNESS WHEREOF, each of the parties has caused this Agreement to be
executed on its behalf by its officer thereunto duly authorized, all as of the
day and year first above written.



                                     HARSCO CORPORATION


                                     By: /s/ Barry M. Sullivan
                                         ---------------------------------------
                                         Name:  Barry M. Sullivan
                                         Title:  Vice President-Corporate
                                                     Development and Treasurer


                                     H-CHEMI ACQUISITION CORP.


                                     By: /s/ Barry M. Sullivan
                                         ---------------------------------------
                                         Name:  Barry M. Sullivan
                                         Title:  Treasurer




                                     CHEMI-TROL CHEMICAL CO.


                                     By: /s/ Robert W. Woolf
                                         ---------------------------------------
                                         Name:  Robert W. Woolf
                                         Title:  Chairman, President and CEO


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