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                            SCHEDULE 14A INFORMATION
    
          PROXY STATEMENT PURSUANT TO SECTION 14(a) OF THE SECURITIES
                              EXCHANGE ACT OF 1934
                             (AMENDMENT NO.      )
 
     Filed by the registrant [ ]
 
     Filed by a party other than the registrant [X]
 
     Check the appropriate box:
 
     [ ] Preliminary proxy statement        [ ] Confidential, for Use of the
                                                Commission Only (as permitted by
                                                Rule 14a-6(e)(2))
 
     [ ] Definitive proxy statement
 
   
     [X] Definitive additional materials
    
 
     [ ] Soliciting material pursuant to Rule 14a-11(c) or Rule 14a-12
 
                               SAFETY-KLEEN CORP.
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                (Name of Registrant as Specified in Its Charter)
 
                      LAIDLAW ENVIRONMENTAL SERVICES, INC.
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    (Name of Person(s) Filing Proxy Statement, if other than the Registrant)
 
Payment of filing fee (Check the appropriate box):
 
     [X] No fee required.
 
     [ ] Fee computed on table below per Exchange Act Rules 14a-6(a)(1) and
0-11.
 
     (1) Title of each class of securities to which transaction applies:
 
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     (2) Aggregate number of securities to which transaction applies:
 
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     (3) Per unit price or other underlying value of transaction computed
pursuant to Exchange Act Rule 0-11 (Set forth the amount on which the filing fee
is calculated and state how it was determined):
 
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     (4) Proposed maximum aggregate value of transaction:
 
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     (5) Total fee paid:
 
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     [ ] Fee paid previously with preliminary materials.
 
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     [ ] Check box if any part of the fee is offset as provided by Exchange Act
Rule 0-11(a)(2) and identify the filing for which the offsetting fee was paid
previously. Identify the previous filing by registration statement number, or
the form or schedule and the date of its filing.
 
     (1) Amount previously paid:
 
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     (2) Form, schedule or registration statement no.:
 
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     (3) Filing party:
 
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     (4) Date filed:
 
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            INSTITUTIONAL SHAREHOLDER SERVICES REPORT FINDS LAIDLAW
                          ENVIRONMENTAL OFFER SUPERIOR


         COLUMBIA, S.C. - February 6, 1998 - Laidlaw Environmental Services,
Inc. (NYSE:LLE) today announced that Institutional Shareholders Services (ISS),
the nation's leading independent proxy advisory firm, has released a report
stating that the Laidlaw Environmental offer for Safety-Kleen Corp. (NYSE:SK)
is "superior" to the terms of the proposed merger between Safety-Kleen and
affiliates of Philip Services Corp., and that Safety-Kleen's poison pill "is
being used to deter a higher offer." The report concludes by stating that
Safety-Kleen shareholders "should not support the [Philip Group] merger
agreement," and recommends that Safety-Kleen shareholders vote against the
Philip Group merger.

Laidlaw Environmental Services is the leading provider of hazardous and
industrial waste management services to industry and government. The company
operates from more than 100 locations throughout North America. 

CONTACT: Kenneth W. Winger, President and Chief Executive Officer, or Paul R.
Humphreys, Senior Vice President, Finance and Chief Financial Officer, Laidlaw
Environmental Services, Inc. 803-933-4210.