<PAGE>



                                 UNITED STATES

                       SECURITIES AND EXCHANGE COMMISSION
                             Washington, D.C. 20549


                                    FORM 10-Q


 QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES
                              EXCHANGE ACT OF 1934


                For the Quarterly Period Ended November 30, 1999


                         Commission File Number 1-8368


                               SAFETY-KLEEN CORP.
                               -----------------
             (Exact name of registrant as specified in its charter)


            Delaware                                         51-0228924
-------------------------------                            ------------------
(State or other jurisdiction of                             (I.R.S. Employer
 incorporation or organization)                              Identification No.)


1301 Gervais Street Columbia, Suite 300, South Carolina                 29201
-------------------------------------------------------               ----------
      (Address of principal executive offices)                        (Zip Code)

       (803) 933-4200 (Registrant's telephone number, including area code)
       --------------

   ---------------------------------------------------------------------------
   (Former name, address and former fiscal year, if changed since last report)

     Indicate by check mark whether the registrant (1) has filed all reports
required to be filed by Sections 13 or 15(d) of the Securities Exchange Act of
1934 during the preceding 12 months (or for such shorter period that the
registrant was required to file such reports), and (2) has been subject to such
filing requirements for the past 90 days.

                            Yes   X     No ____
                                 ---

          The number of shares of the issuer's common stock outstanding as of
     January 12, 2000 was 100,637,975



<PAGE>


                                                         SAFETY-KLEEN CORP.


                                                                INDEX

<TABLE>
<CAPTION>
PART 1     FINANCIAL INFORMATION

Item 1     Financial Statements
<S>        <C>                                                                                                     <C>

           Consolidated Statements of Income for the Three Month Periods Ended
                November 30, 1999 and 1998......................................................................... 2

           Consolidated Statements of Comprehensive Income for the Three Months Ended
                November 30, 1999 and 1998......................................................................... 3

           Consolidated Balance Sheets as of November 30, 1999 and August 31, 1999................................. 4

           Consolidated Statements of Cash Flows for the Three Months  Ended
                November 30, 1999 and 1998......................................................................... 5

           Notes to Unaudited Consolidated Financial Statements for the Three Months  Ended
                November 30, 1999 and 1998......................................................................... 6


Item 2     Management's Discussion and Analysis of Financial Condition and Results of Operations  .................13


PART II    OTHER INFORMATION

Item 1     Legal Proceedings....................................................................................... 19

Item 2     Changes In Securities and Use Of Proceeds............................................................... 20

Item 4     Submission of Matters to a Vote of Security Holders..................................................... 20

Item 6     Exhibits and Reports on Form 8-K........................................................................ 21


Signatures......................................................................................................... 33

</TABLE>


                                       1
<PAGE>



                               SAFETY-KLEEN CORP.
                        CONSOLIDATED STATEMENTS OF INCOME
                     ($ in thousands, except per share data)
                                   (Unaudited)
                                                              Three Months Ended
                                                                  November 30,
                                                                  ------------
                                                              1999        1998
                                                              ----        ----
Revenues ...............................................    $408,481    $467,019
                                                            --------    --------

Expenses:
   Operating ...........................................     257,472     305,048
   Depreciation and amortization .......................      33,703      37,295
   Selling, general and administrative .................      34,250      34,500
                                                            --------    --------
     Total expenses ....................................     325,425     376,843
                                                            --------    --------
Operating income .......................................      83,056      90,176
Interest expense, net ..................................      40,135      43,084
Equity in earnings of associated company ...............       1,005        --
                                                            --------    --------
Income before income tax expense .......................      43,926      47,092
Income tax expense .....................................      19,219      19,320
                                                            --------    --------
Net income .............................................    $ 24,707    $ 27,772
                                                            ========    ========

Basic income per share:
   Net income ..........................................    $   0.25    $   0.32
                                                            ========    ========
   Weighted average common stock outstanding (000s) ....     100,637      87,844
                                                            ========    ========

Diluted income per share:
   Net income ..........................................    $   0.25    $   0.27
                                                            ========    ========
   Weighted average common stock outstanding and
     assumed conversions (000s) ........................     100,637     111,242
                                                            ========    ========




      See accompanying Notes to Unaudited Consolidated Financial Statements


                                       2
<PAGE>


                               SAFETY-KLEEN CORP.
                 CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME
                                ($ in thousands)
                                   (Unaudited)


                                                              Three Months Ended
                                                                  November 30,
                                                                  ------------
                                                                1999      1998
                                                                ----      ----
Net income .................................................. $24,707   $27,772
Other comprehensive income, net of tax:
   Unrealized foreign currency translation adjustment .......   1,837     1,492
                                                              -------   -------
Other comprehensive income ..................................   1,837     1,492
                                                              -------   -------
Comprehensive income ........................................ $26,544   $29,264
                                                              =======   =======




           See accompanying Notes to Unaudited Consolidated Financial Statements

                                       3
<PAGE>


                               SAFETY-KLEEN CORP.
                           CONSOLIDATED BALANCE SHEETS
                                ($ in thousands)

<TABLE>

                                                             November 30,
                                                               1999
                                                             (Unaudited)  August 31, 1999
                                                             -----------  ---------------
<S>                                                          <C>            <C>

ASSETS
   Current assets
     Cash and cash equivalents ...........................   $     5,932    $     9,173
     Trade and other accounts receivable, net of allowance
      for doubtful accounts .............................        446,917        395,009
     Inventories and supplies ............................        75,117         60,567
     Deferred income taxes ...............................        58,659         58,641
     Other current assets ................................        54,466         50,005
                                                             -----------    -----------
       Total current assets ..............................       641,091        573,395
   Long-term investments .................................        80,134         76,739
   Property, plant and equipment, net ....................     2,597,275      2,585,191
   Goodwill, net of amortization .........................     1,092,362      1,098,731
   Other assets ..........................................        39,280         35,289
                                                             -----------    -----------
     Total assets ........................................   $ 4,450,142    $ 4,369,345
                                                             ===========    ===========

LIABILITIES
   Current liabilities
     Accounts payable ....................................   $   189,408    $   172,838
     Accrued liabilities .................................       121,515        163,818
     Current portion of long-term debt ...................        91,796         85,063
                                                             -----------    -----------
       Total current liabilities .........................       402,719        421,719
   Environmental and other long-term liabilities .........       203,816        226,631
   Long-term debt ........................................     1,961,640      1,882,371
   Deferred income taxes .................................       573,145        556,372
                                                             -----------    -----------
     Total liabilities ...................................     3,141,320      3,087,093
                                                             -----------    -----------

   Commitments and contingencies .........................          --             --
                                                             -----------    -----------

STOCKHOLDERS' EQUITY
   Common stock, par value $1.00 per share; authorized
    250,000,000; issued and outstanding 100,637,975 -
    November 30, 1999; 100,635,975 - August 31, 1999 .....       100,638        100,636
   Additional paid-in capital ............................     1,342,472      1,342,448
   Accumulated other comprehensive income ................       (11,112)       (12,949)
   Accumulated deficit ...................................      (123,176)      (147,883)
                                                             -----------    -----------
     Total stockholders' equity ..........................     1,308,822      1,282,252
                                                             -----------    -----------
     Total liabilities and stockholders' equity ..........   $ 4,450,142    $ 4,369,345
                                                             ===========    ===========


          See accompanying Notes to Unaudited Consolidated Financial Statements

</TABLE>
                                       4
<PAGE>


                               SAFETY-KLEEN CORP.
                      CONSOLIDATED STATEMENTS OF CASH FLOWS
                                ($ in thousands)
                                   (Unaudited)
<TABLE>


                                                                         Three Months Ended
                                                                             November 30,
                                                                             ------------
                                                                         1999           1998
                                                                         ----           ----
<S>                                                                  <C>              <C>

Cash flows from operating activities:
   Net income                                                        $   24,707       $ 27,772
   Adjustments to reconcile net income to net cash provided
     by (used in) operations:
       Equity in undistributed earnings of associated companies          (1,005)            --
       Depreciation and amortization                                     33,703         37,295
       Deferred income taxes                                             15,567         11,060
       Change in working capital and other items                       (115,648)       (19,924)
                                                                     -----------      ---------
Net cash provided by (used in) operating activities                     (42,676)        56,203
                                                                     -----------      --------

Cash flows from investing activities:
   Cash expended on business acquisitions                               (20,000)        (4,058)
   Purchases of property, plant and equipment                           (19,724)       (14,424)
   Increase in long-term investments                                     (1,422)           (53)
   Change in other, net                                                    (945)         1,090
                                                                     -----------      --------
Net cash used in investing activities                                   (42,091)       (17,445)
                                                                     -----------      ---------

Cash flows from financing activities:
   Issuance of common stock on exercise of stock options                     26             --
   Net borrowings (repayments) of long-term debt                         82,106        (45,307)
                                                                      ---------       ---------
Net cash provided by (used in) financing activities                      82,132        (45,307)
                                                                     ----------       ---------

Effect of exchange rate changes on cash                                    (606)        (5,203)
                                                                     -----------      ---------

Net decrease in cash and cash equivalents                                (3,241)       (11,752)
Cash and cash equivalents at:
   Beginning of period                                                    9,173         16,333
                                                                     ----------       --------
   End of period                                                     $    5,932       $  4,581
                                                                     ==========       ========

</TABLE>



           See accompanying Notes to Unaudited Consolidated Financial Statements

                                       5
<PAGE>


                               SAFETY-KLEEN CORP.
              Notes to Unaudited Consolidated Financial Statements
                  For the Three Months Ended November 30, 1999


NOTE 1 - BASIS OF PRESENTATION

The accompanying  unaudited interim consolidated  financial statements have been
prepared  in  accordance  with the  instructions  to Form 10-Q and Rule 10-01 of
Regulation S-X and, therefore, do not include all of the disclosures required by
generally accepted accounting principles for annual financial statements. In the
opinion  of  management,   all  adjustments  considered  necessary  for  a  fair
presentation  of the  interim  period  results  have  been  included;  all  such
adjustments are of a normal recurring  nature.  Operating  results for the three
months ended  November 30, 1999 are not  necessarily  indicative  of the results
that may be expected  for the full fiscal year  ending  August 31,  2000.  These
statements  should  be read  in  conjunction  with  the  consolidated  financial
statements, including the accounting policies, and notes thereto included in the
Registrant's  Annual Report on Form 10-K, filed with the Securities and Exchange
Commission on October 29, 1999.  Certain amounts as of August 31, 1999 have been
reclassified to conform to the current period's presentations.

NOTE 2 - SEGMENT INFORMATION

The Company is organized along its two primary business  activities - Collection
and Recovery and Treatment and Disposal.  Each of these two segments are managed
independently  from the other and report  separately to senior  management.  The
Company  evaluates  performance  based on several factors,  of which the primary
financial  measure is operating  income  before  depreciation  and  amortization
("EBITDA").  The  table  below  reflects  certain  information  relating  to the
Company's operations ($ in thousands):

                                       6

<PAGE>

<TABLE>

                                  Collection    Treatment
                                 and Recovery  and Disposal Europe     Other       Total
                                 ------------  -------------------     -----       -----
<S>                                <C>          <C>        <C>        <C>         <C>
Three Months Ended
  November 30, 1999
   Outside revenue .............   $339,571     $ 68,910   $   --     $   --      $408,481
   Intercompany revenue ........     15,227       36,095       --      (51,322)       --
   Depreciation and amortization     18,006        8,179       --        7,518      33,703
   EBITDA ......................     99,769       37,425       --      (20,435)    116,759

Three Months Ended
  November 30, 1998
   Outside revenue .............   $340,919     $ 94,400   $ 31,700   $   --      $467,019
   Intercompany revenue ........      7,532       29,071       --      (36,603)       --
   Depreciation and amortization     17,507        9,276      3,438      7,074      37,295
   EBITDA ......................    110,880       35,954      7,605    (26,968)    127,471

</TABLE>

Reconciliation  of reportable  segment  primary  financial  measure to operating
income is as follows ($ in thousands):

                                                          Three Months Ended
                                                          ------------------
                                                              November 30,
                                                              ------------
                                                         1999         1998
                                                         ----         ----
Total EBITDA                                          $ 116,759    $ 127,471
Depreciation and amortization                            33,703       37,295
                                                      ---------    ---------
   Operating income                                   $  83,056    $  90,176
                                                      =========    =========

NOTE 3 - STOCKHOLDERS' EQUITY

Changes in the components of stockholders' equity since September 1, 1999 are as
follows ($ in thousands):

<TABLE>

                                                        Accumulated
                                           Additional      Other                      Total
                                 Common     Paid-In    Comprehensive  Accumulated  Stockholders'
                                 Stock      Capital        Income       Deficit       Equity
                                 -----      -------        ------       -------       ------
<S>                           <C>          <C>          <C>           <C>           <C>
Balance, September 1, 1999    $  100,636   $1,342,448   $  (12,949)   $ (147,883)   $1,282,252
Net income for period .....         --           --           --          24,707        24,707
Issuance of shares ........            2           24         --            --              26
Cumulative foreign currency
   translation adjustment .         --           --          1,837          --           1,837
                              ----------   ----------   ----------    ----------    ----------
Balance, November 30, 1999    $  100,638   $1,342,472   $  (11,112)   $ (123,176)   $1,308,822
                              ==========   ==========   ==========    ==========    ==========
</TABLE>

NOTE 4 - STATEMENTS OF CASH FLOWS

The non-cash  transactions for the three months ended November 30, 1999 and 1998
are as follows ($ in thousands):

                                                              Three Months Ended
                                                                 November 30,
                                                                 ------------
                                                                1999       1998
                                                                ----       ----
Non-cash investing and financing activities:
   Issuance of common stock to satisfy interest payment
      due on subordinated convertible debenture                 $  --    $ 8,750
   Issuance of common stock to satisfy payment of directors'
      fees                                                         --         93
                                       7
<PAGE>

NOTE 5 - SUMMARIZED FINANCIAL INFORMATION

The Senior  Subordinated  Notes (the "Notes") issued by  Safety-Kleen  Services,
Inc.,  a  consolidated  subsidiary  of the  Company,  are jointly and  severally
guaranteed by Safety-Kleen Corp. and all wholly-owned  domestic  subsidiaries of
the  Company  on a full and  unconditional  basis.  The  Notes  contain  certain
covenants,  which,  among other things,  restrict the payment of dividends  from
Safety-Kleen Services,  Inc. and its subsidiary guarantors to Safety-Kleen Corp.
Summarized  financial  information for each of Safety-Kleen Corp.,  Safety-Kleen
Services, Inc., the subsidiary guarantors,  and the subsidiary non-guarantors on
a consolidating  basis are presented below.  Separate  financial  statements and
other disclosures  concerning the subsidiary guarantors are not included because
management believes that they are not material to investors.

                                       8
<PAGE>
<TABLE>

                                               Consolidating Condensed Balance Sheet
                                                         November 30, 1999
                                                            (Unaudited)


                                                       Safety-Kleen                 Subsidiary
                                          Safety-Kleen   Services,    Subsidiary       Non-      Elimination    Consolidated
($ in thousands) .....................        Corp.         Inc.      Guarantors    Guarantors     Entries         Totals
                                          ------------ ------------   ----------    ----------   -----------    ------------
<S>                                      <C>           <C>           <C>           <C>           <C>            <C>

ASSETS
Current assets .......................   $    22,506   $      --     $   578,842   $    56,358   $   (16,615)   $   641,091
Property, plant and
   equipment, net ....................          --            --       2,405,176       192,099          --        2,597,275
Investment in subsidiaries ...........     1,627,025     3,040,176     2,597,252             3    (7,264,456)          --
Goodwill .............................          --            --       1,035,779        56,583          --        1,092,362
Other non-current assets .............          --            --         118,036         1,378          --          119,414
                                         -----------   -----------   -----------   -----------   -----------    -----------
   Total assets ......................   $ 1,649,531   $ 3,040,176   $ 6,735,085   $   306,421   $(7,281,071)   $ 4,450,142
                                         ===========   ===========   ===========   ===========   ===========    ===========

LIABILITIES
Current liabilities ..................   $     2,460   $   117,404   $   241,457   $    58,013   $   (16,615)   $   402,719
Non-current liabilities ..............          --            --         765,270        11,691          --          776,961
Long-term debt .......................       338,249     1,568,384        15,656        39,351          --        1,961,640
Subordinated convertible
   debenture .........................          --            --            --            --            --             --
                                         -----------   -----------   -----------   -----------   -----------    -----------
   Total liabilities .................       340,709     1,685,788     1,022,383       109,055       (16,615)     3,141,320

STOCKHOLDERS'  EQUITY ................     1,308,822     1,354,388     5,712,702       197,366    (7,264,456)     1,308,822
                                         -----------   -----------   -----------   -----------   -----------    -----------
Total liabilities and
   stockholders' equity ..............   $ 1,649,531   $ 3,040,176   $ 6,735,085   $   306,421   $(7,281,071)   $ 4,450,142
                                         ===========   ===========   ===========   ===========   ===========    ===========
</TABLE>

<TABLE>
                                            Consolidating Condensed Statement of Income
                                               Three Months Ended November 30, 1999
                                                            (Unaudited)


                                                Safety-Kleen              Subsidiary
                                   Safety-Kleen   Services,   Subsidiary      Non-     Elimination  Consolidated
($ in thousands)                       Corp.        Inc.      Guarantors   Guarantors    Entries       Totals
                                       -----        ----      ----------   ----------    -------       ------
<S>                                 <C>          <C>          <C>          <C>         <C>          <C>

Total revenues ...............      $    --      $    --      $ 357,990    $  55,644   $  (5,153)    $ 408,481
Operating expenses ...........            500         --        290,942       39,136      (5,153)      325,425
                                    ---------    ---------    ---------    ---------   ---------     ---------
Operating income (loss) ......           (500)        --         67,048       16,508        --          83,056
Interest expense (income), net          7,422       30,577         (101)       2,237        --          40,135
Equity in undistributed
   earnings of subsidiaries ..         29,228       46,680        1,005         --       (75,908)        1,005
                                    ---------    ---------    ---------    ---------   ---------     ---------
Income before income
   tax expense ...............         21,306       16,103       68,154       14,271     (75,908)       43,926
Income tax expense (benefit) .         (3,401)     (13,125)      29,256        6,489        --          19,219
                                    ---------    ---------    ---------    ---------   ---------     ---------
Net income ...................      $  24,707    $  29,228    $  38,898    $   7,782   $ (75,908)    $  24,707
                                    =========    =========    =========    =========   =========     =========
</TABLE>

                                                                 9

<PAGE>

<TABLE>
                                          Consolidating Condensed Statement of Cash Flows
                                               Three Months Ended November 30, 1999
                                                            (Unaudited)


                                                   Safety-Kleen                 Subsidiary
                                     Safety-Kleen    Services,    Subsidiary        Non-     Elimination  Consolidated
($ in thousands)                         Corp.         Inc.       Guarantors    Guarantors     Entries       Totals
                                         -----         ----       ----------    ----------     -------       ------
<S>                                   <C>           <C>           <C>           <C>           <C>          <C>

Net cash provided by (used in)
   operating activities .......       $ (19,195)    $ (18,017)    $ (25,244)    $  11,806     $  7,974     $ (42,676)
                                      ----------    ----------    ----------    ----------    ---------    ----------
Cash flows from investing
   activities:
Cash expended on
   acquisition of business ....             --            --        (20,000)          --           --        (20,000)
Proceeds from sale of property,
   plant and equipment ........             --            --            --            --           --            --
Purchases of property, plant
   and equipment ..............             --            --        (18,091)       (1,633)         --        (19,724)
Increase in long-term
   investments ................             --            --         (1,422)          --           --         (1,422)
Change in other, net ..........             --            --           (946)            1          --           (945)
                                      ----------    ----------    ----------    ----------    ---------    ----------
Net cash (used in)
   investing activities .......             --            --        (40,459)       (1,632)         --        (42,091)
                                      ----------    ----------    -----------   ----------    ---------    ---------
Cash flows from financing
   activities:
Issuance of common stock on
   exercise of stock options ..              26           --            --            --           --             26
Borrowings of long-term debt ..             --            --            --            --           --            --
Repayment of long-term debt ...             --         84,894          (142)       (2,646)         --         82,106
Bank overdraft ................             --           --             --            --           --            --
Intercompany payable
   (receivable) ...............           8,939       (66,877)       65,845        (7,907)         --            --
                                      ----------    ----------    ----------    ----------    ---------    ----------
Net cash provided by (used in)
   financing activities .......           8,965        18,017        65,703       (10,553)         --         82,132
                                      ----------    ----------    -----------   ----------    ---------    ----------
Effect of exchange rate
   changes on cash ............             --            --            --           (606)         --           (606)
                                      ----------    ----------    -----------   ----------    ---------    ----------
Net decrease in cash and cash
   equivalents ................         (10,230)          --            --           (985)       7,974        (3,241)
Cash and cash equivalents at:
   Beginning of period ........           22,445          --            --          1,026      (14,298)        9,173
                                      ----------    ----------    -----------   ----------    ---------    ----------
   End of period ..............       $   12,215    $     --      $     --      $      41     $ (6,324) $      5,932
                                      ==========    ==========    ==========    ==========    =========    ==========

</TABLE>

                                                                10

<PAGE>

<TABLE>
                                               Consolidating Condensed Balance Sheet
                                                          August 31, 1999


                                           Safety-Kleen                  Subsidiary
                            Safety-Kleen     Services,     Subsidiary       Non-        Elimination   Consolidated
($ in thousands)                Corp.          Inc.        Guarantors    Guarantors       Entries        Totals
                               -----           ----        ----------    ----------       -------        ------
<S>                         <C>            <C>            <C>            <C>           <C>            <C>

ASSETS
Current assets ...........  $    24,956    $       --     $   514,319    $   48,418    $   (14,298)   $   573,395
Property, plant and
   equipment, net ........         --              --       2,397,277       187,914           --        2,585,191
Investment in subsidiaries    1,601,498      2,911,631      2,346,621           --      (6,859,750)           --
Goodwill .................         --              --       1,042,315        56,416            --       1,098,731
Other non-current assets .         --              --         110,672         1,356            --         112,028
                            -----------    -----------    -----------    ----------    ------------   -----------
   Total assets ..........  $ 1,626,454    $ 2,911,631    $ 6,411,204    $  294,104    $(6,874,048)   $ 4,369,345
                            ===========    ===========    ===========    ==========    ============   ===========

LIABILITIES
Current liabilities ......  $     7,189    $   100,208    $   277,455    $   51,165        (14,298)   $   421,719
Non-current liabilities ..         --              --         777,149         5,854            --         783,003
Long-term debt ...........      337,013      1,488,126         15,798        41,434            --       1,882,371
                            -----------    -----------    -----------    ----------    ------------   -----------
   Total liabilities .....      344,202      1,588,334      1,070,402        98,453        (14,298)     3,087,093

STOCKHOLDERS'  EQUITY ....    1,282,252      1,323,297      5,340,802       195,651     (6,859,750)     1,282,252
                            -----------    -----------    -----------    ----------    ------------   -----------
Total liabilities and
   stockholders' equity ..  $ 1,626,454    $ 2,911,631    $ 6,411,204    $  294,104    $(6,874,048)   $ 4,369,345
                            ===========    ===========    ===========    ==========    ============   ===========
</TABLE>

<TABLE>
                                            Consolidating Condensed Statement of Income
                                               Three Months Ended November 30, 1998
                                                            (Unaudited)


                                              Safety-Kleen                Subsidiary
                                Safety-Kleen     Services,  Subsidiary        Non-      Elimination   Consolidated
($ in thousands)                   Corp.           Inc.     Guarantors    Guarantors      Entries        Totals
                                   -----           ----     ----------    ----------      -------        ------
<S>                              <C>           <C>          <C>           <C>           <C>            <C>

Total revenues ...............   $    --       $    --      $ 354,362     $ 123,171     $  (10,514)    $ 467,019
Operating expenses ...........        --            --        300,382        86,975        (10,514)      376,843
                                 --------      ---------    ----------    ----------    -----------    ---------
Operating income .............       --             --         53,980        36,196            --         90,176
Interest expense (income), net      6,412        36,591        (7,400)        7,481            --         43,084
Undistributed earnings
   of subsidiaries ...........     31,504        52,800           --            --         (84,304)          --
                                 --------      ---------    ----------    ----------    -----------    ---------
Income before income
   tax expense (benefit) .....     25,092        16,209        61,380        28,715        (84,304)       47,092
Income tax expense (benefit) .     (2,680)      (15,295)       25,639        11,656            --         19,320
                                 ---------     ---------    ----------    ----------    ----------     ---------
Net income ...................   $ 27,772      $ 31,504     $  35,741     $  17,059     $  (84,304)    $  27,772
                                 =========     =========    ==========    ==========    ===========    =========

</TABLE>

                                                                11
<PAGE>

<TABLE>
                                          Consolidating Condensed Statement of Cash Flows
                                               Three Months Ended November 30, 1998
                                                            (Unaudited)


                                                    Safety-Kleen                   Subsidiary
                                     Safety-Kleen     Services,     Subsidiary        Non-      Elimination    Consolidated
($ in thousands)                        Corp.           Inc.        Guarantors     Guarantors     Entries         Totals
                                        -----           ----        ----------     ----------     -------         ------
<S>                                   <C>            <C>            <C>            <C>           <C>            <C>

Net cash provided by (used in)
   operating activities               $  (3,527)     $ (18,185)     $ 107,126      $ (29,211)    $    --        $  56,203
                                      ----------     ----------     --------       ----------    ---------      ----------
Cash flows from investing
   activities:
Cash expended on
   acquisition of business ...              --             --          (4,058)           --           --           (4,058)
Proceeds from sale of business              --             --             --             --           --              --
Proceeds from sale of
   property, plant and
   equipment .................              --             --             693            397          --            1,090
Purchases of property, plant
   and equipment .............              --             --         (10,300)        (4,124)         --          (14,424)
Increase in long-term
   investments ...............              --             --             (53)           --           --              (53)
Change in other, net .........              --             --             --             --           --              --
                                      ----------     ----------     ----------     ----------    ---------      ----------
Net cash (used in) investing
   activities ................              --             --         (13,718)        (3,727)         --          (17,445)
                                      ----------     ----------     ----------     ----------    ---------      ----------
Cash flows from financing
   activities:
Issuance of common stock on
   exercise of stock options .              --             --             --             --           --              --
Borrowings of long-term debt .              --             --             --             --           --              --
Repayment of long-term debt ..              --         (44,611)          (696)           --           --          (45,307)
Bank financing fees ..........              --             --             --             --           --              --
Intercompany payable
   (receivable) ..............            3,527         62,796        (96,624)        30,301          --              --
                                      ----------     ----------     ----------     ----------    --------       ----------
Net cash provided by (used in)
   financing activities ......            3,527         18,185        (97,320)        30,301          --          (45,307)
                                      ----------     ----------     ----------     ----------    ---------      ----------
Effect of exchange rate
   changes on cash ...........              --             --             --          (5,203)         --           (5,203)
                                      ----------     ----------     ----------     ----------    ---------      ----------
Net decrease in cash and
   cash equivalents ..........              --             --          (3,912)        (7,840)         --          (11,752)
Cash and cash equivalents at:
   Beginning of period .......              --             --           4,343         11,990          --           16,333
                                      ----------     ----------     ---------      ----------    ---------      ----------
   End of period .............        $     --       $     --       $     431      $   4,150     $    --        $   4,581
                                      ==========     ==========     ==========     ==========    =========      ==========

</TABLE>
                                                                12

<PAGE>

MANAGEMENT'S DISCUSSION AND ANALYSIS OF FINANCIAL CONDITION AND RESULTS
OF OPERATIONS

         The following  discussion  and analysis  should be read in  conjunction
with the Company's  consolidated  financial statements and related notes thereto
included elsewhere herein.

         The following  discussion  and analysis  includes  statements  that are
considered  forward-looking  based on the Company's  expectations  and, as such,
these  statements  are subject to  uncertainty  and risk.  See "Factors That May

Affect Future Results" below.

Results of Operations:

Three Months Ended  November 30, 1999 compared with Three Months Ended  November
30, 1998

Operating results are as follows ($ in millions):

                                             Three Months Ended November 30,
                                                  1999               1998
                                                  ----               ----

Revenues ..............................   $ 408.5    100.0%   $ 467.0    100.0%
Operating expense .....................     257.5     63.1%     305.0     65.3%
Depreciation and amortization .........      33.7      8.2%      37.3      8.0%
Selling, general and administrative ...      34.2      8.4%      34.5      7.4%
                                          -------    ------   -------    ------
Operating income ......................   $  83.1     20.3%   $  90.2     19.3%
                                          =======    ======   =======    ======


Revenues

Components of revenue ($ in millions):      Three Months Ended November 30,
                                            -------------------------------
                                                   1999             1998
                                            ---------------   --------------
Collection and Recovery Services

    Industrial Services .................   $ 193.6    47%    $ 206.2    44%
    Commercial and Institutional Services     146.0    36%      134.7    29%
                                            -------   ----     ------   ----
Total Collection and Recovery Services ..     339.6    83%      340.9    73%

Treatment and Disposal Services .........      68.9    17%       94.4    20%

European Operations .....................       0.0     0%       31.7     7%
                                            -------   ----     ------   ----

     Total revenue ......................   $ 408.5   100%    $ 467.0   100%
                                            =======   ====    =======   ====


                                       13
<PAGE>

         Revenues  decreased  $58.5 million,  or 12.5%,  during the three months
ended  November 30, 1999,  compared to the three months ended November 30, 1998.
Revenue from collection and recovery services to industrial  customers decreased
$12.6 million, or 6.1%, while collection and recovery services to commercial and
institutional customers increased $11.3 million, or 8.4%. Revenue from treatment
and disposal  services  decreased  $25.5  million,  or 27%,  primarily  due to a
reduction  in the  level  of  activity  at the  Company's  harbor  dredging  and
treatment operations.

         The   Company   eliminates   inter-company   revenues   in   presenting
consolidated  financial results.  The majority of such eliminations occur at the
Company's  disposal  facilities  which  receive waste streams from the Company's
collection and recovery services network.

         Management's estimate of the components of the changes in the Company's
consolidated revenue is as follows:

                                                 Percentage Increase (Decrease)
                                                 Three Months Ended November 30,

                                                         1999 over 1998

Expansion of customer base by acquisition                     1.7%
Other, primarily through volume and price changes            (8.0%)
Divestitures and closures                                    (6.8%)
Foreign exchange rate changes                                 0.6%
                                                             ------
     Total                                                  (12.5%)

         The revenue increase from acquisitions related to a used oil collection
business acquired on September 1, 1999.  Revenues from existing  operations were
impacted by a  significant  reduction in the level of activity in the  Company's
harbor  dredging and  treatment  operations  within the  treatment  and disposal
component.  Revenues from these  operations of nil in the current period compare
to revenues of $19.4 million in the prior year period. Excluding harbor dredging
and treatment  operations,  price and volume  changes from  existing  operations
would have declined by 4.3%,  due primarily to reductions in event work activity
in the treatment and disposal and  industrial  services  components.  Prior year
revenues included  contributions  from the Company's  European  Operations which
were  deconsolidated  as of November  30,  1998.  An increase in revenues due to
foreign exchange rate changes resulted from a relative  increase in the Canadian
dollar translation rate.

         It is expected  that  revenues will be lower for the three month period
ending  February 29, 2000  compared to the three months ended  November 30, 1999
due to the traditional  seasonality  impact of fewer working days and a decrease
in customer activity  associated with holiday down-time within their operations.
In addition,  the  revenues  for the three  months  ended  February 28, 1999 had
previously  included  the  predecessor   Safety-Kleen's   year-end  sales  drive
(December  31),  which drive now coincides  with the Company's  August 31 fiscal
year end.


                                       14
<PAGE>


         For  the  third  and  fourth  quarters  of  fiscal  2000,  the  Company
anticipates  moderate  revenue  growth of 1.5% to 1.75%  adjusted for  differing
business days (on a  quarter-to-quarter  basis) in its  collection  and recovery
line of business. The Company also expects to generate revenues of approximately
$300 million in fiscal 2000 in its treatment and disposal line of business.  The
Company's  revenue estimates are based on current market conditions and could be
impacted by any of the factors  described  in  "Factors  That May Affect  Future
Results".

Operating Expense

         Operating expenses decreased $47.5 million,  or 15.6%, during the three
months ended November 30, 1999,  compared to the three months ended November 30,
1998. The reduction was primarily  attributable  to the  deconsolidation  of the
Company's European Operations and the reduction in harbor dredging and treatment
operations.  As a percentage of revenue,  operating  expense  decreased to 63.1%
from 65.3% in the prior year,  primarily  due to the  increased  utilization  of
existing  facilities  and other  operational  assets,  acquisition  related cost
reduction measures,  primarily personnel related costs, and an decrease in lower
margin business.

Depreciation and Amortization Expense

         Depreciation and amortization  expense decreased $3.6 million, or 9.6%,
during the three months ended November 30, 1999, compared to the prior year. The
decrease was  primarily  attributable  to the  deconsolidation  of the Company's
European Operations.  As a percentage of revenue,  depreciation and amortization
expense was 8.2%, compared to 8.0% in the prior year.

Selling, General and Administrative Expense

         Selling, general and administrative expenses decreased $0.3 million, or
0.9%, during the three months ended November 30, 1999, versus the prior year. As
a percentage of revenue,  selling, general and administrative expenses increased
to 8.4% from 7.4% in the prior  year due to  increased  selling  costs and lower
than average administrative costs for the deconsolidated European Operations.

Interest Expense

         Interest  expense  decreased  $4.0 million,  or 9.1%,  during the three
months ended November 30, 1999, over the prior year as a result of the reduction
in long term debt outstanding.

Equity in Earnings of Associated Companies

         On December 23,  1998,  the Company sold a 56% interest in its European
operations.   The  Company's  remaining  interest  in  the  European  Operations
contributed  $1.0 million on an equity basis for the three months ended November
30, 1999. The Company intends to permanently  reinvest its share of the earnings
of the European Operations.


                                       15
<PAGE>

Income Tax Expense

         The effective tax rate of 45% on income before  restructuring and other
charges,  equity earnings and taxes ($43.1 million) has increased over the prior
year effective  rate primarily due to the sale of 56% of the Company's  European
operations.  The European operations had an effective tax rate below that of the
overall Company average.


FACTORS THAT MAY AFFECT FUTURE RESULTS

         This report  contains  various  forward-looking  statements  within the
meaning of the  Private  Securities  Litigation  Reform  Act of 1995,  including
financial,  operating  and  other  projections.  These  statements  are based on
current plans and  expectations of the Company and involve a number of risks and
uncertainties   that  could  cause  actual  future  activities  and  results  of
operations   to  be   materially   different   from   those  set  forth  in  the
forward-looking statements.

         Important  factors that could cause actual  results to differ  include,
among others,  risks associated with  acquisitions and fluctuations in operating
results  because  of  acquisitions;  impact  of new  and  existing  competitors;
successful   integration  of  the  former  Laidlaw  Environmental  Services  and
Safety-Kleen  industrial sales forces;  implementation  of a common  operational
management  information  system in the  industrial  services and  treatment  and
disposal lines of business;  general level of economic activity in North America
remaining  constant;  the ability of the Company to  effectively  introduce  new
product  offerings;  the ability of the Company to increase cash  collections of
accounts receivable; changes in applicable government regulations (environmental
and other),  the impact of  litigation,  and other factors  described in Part I,
Item 1 of the  Company's  Annual Report on Form 10-K for the Twelve Months Ended
August 31, 1999. As a result of these factors,  the Company's revenue and income
could vary significantly from quarter to quarter, and past financial performance
should not be considered a reliable indicator of future performance.

CAPITALIZATION

         On  November  24,  1998,   the   Company's   shareholders   approved  a
one-for-four reverse stock split which became effective on November 30, 1998. As
a result,  shareholders received one share of Safety-Kleen common stock for each
four shares previously held.

         On November  15, 1998,  the Company  issued  635,208  shares to satisfy
interest due on the subordinated convertible debenture.

         On May 17, 1999, the Company issued 533,333 shares to satisfy  interest
due on the subordinated convertible debenture.


                                       16
<PAGE>

         On May 17, 1999, the Company issued $225 million 9.25% Senior Notes due
2009 (the "Senior Notes") in a private  offering.  Net proceeds from the sale of
the Senior  Notes,  after the  underwriting  discount and other  expenses,  were
approximately  $214  million.  The net  proceeds  were used to finance  the cash
portion of the purchase price for the repurchase of the subordinated convertible
debenture (the  "Repurchase").  The purchase  price also included  approximately
11.3 million common shares of the Company. The issuance of the common shares was
approved at a Special  Meeting of the  stockholders of the Company on August 27,
1999.

         On August  27,  1999,  the  Company  issued  376,858  shares to satisfy
interest  due,  through  the  date  of  the  repurchase,   on  the  subordinated
convertible debenture.

LIQUIDITY

         Total cash used in  operations  during the three months ended  November
30, 1999 was $42.7 million.  This was composed of $66.0 million from  operations
before financing working capital requirements of $101.7 million and $7.0 million
related to spending on acquisition environmental liabilities.

         The  Company's  primary  sources  of  liquidity  are  cash  flows  from
operations,  existing cash and short-term  investments of $5.9 million,  and the
unused cash portion of the Senior Credit  Facility's  revolver tranche of $198.0
million.  The available  portion of this revolver tranche varies from quarter to
quarter.

         The Company's Senior Credit Facility contains negative, affirmative and
financial  covenants  customarily  found in  credit  agreements  for  financings
similar to the financing  provided under the Senior Credit  Facility,  including
covenants  limiting  annual capital  expenditures,  restricting  quarterly debt,
guaranties  and lien amounts,  mergers and  consolidations,  sales of assets and
payment of dividends. The Company was in compliance with all of its covenants at
November 30, 1999.

         The Company's 1999 Notes are effectively  subordinated to the Company's
subsidiaries'  indebtedness.   The  payment  of  dividends,  advances  or  other
distributions from the Company's subsidiaries to the Company, as may be required
to service  the  Senior  Notes,  may be  restricted  as they are  subject to the
various indentures, covenants and other obligations of the subsidiaries.

         Trade and other accounts  receivable  represent the largest  portion of
current  assets,  totaling $446.9 million at November 30, 1999. The average days
sales outstanding ("DSO") increased to 93 days, from 82 days at August 31, 1999.
The DSO increase and the related  increase in working capital was due to billing
and collections systems integration and modifications.  The Company expects days
sales  outstanding  to  decrease  over  the  balance  of  fiscal  2000 as  these
integration  issues are resolved and as systems  modifications  become complete.
The  Company is  targeting  reducing  trade  accounts  receivable  by $15 to $20
million during its second quarter of fiscal 2000.


                                       17
<PAGE>

         The Company  expects to fund capital  expenditures,  debt repayment and
environmental liability requirements from cash flows from operations.

         The Company has not paid  dividends  during the reported  periods,  and
does not intend to pay dividends in the foreseeable  future.  Additionally,  the
Senior  Credit  Facility  prohibits  the  payment of  dividends  (unless a given
percentage of lenders otherwise agree).


CAPITAL EXPENDITURES AND CAPITAL RESOURCES

         Investing activities for the three months ended November 30, 1999, used
cash of $42.1  million.  Net  expenditures  for the purchase of fixed assets for
normal replacement requirements and increases in services were $19.7 million and
$20.0  million was spent  acquiring  new  businesses.  The  Company's  projected
capital  expenditures for fiscal 2000 are approximately $75 to $80 million.  The
Company believes that it has adequate resources to finance these expenditures.


YEAR 2000 READINESS DISCLOSURE

            The Year 2000 ("Y2K") issue is the result of computer programs using
a  two-digit  format,  as opposed to four  digits,  to indicate  the year.  Such
computer  programs will be unable to interpret dates beyond the year 1999, which
could cause a system failure or other computer errors, leading to disruptions in
operations.  The  Company  developed  a  three-phase  program  for  Y2K  systems
compliance.  Phase I identified  those systems with respect to which the Company
had exposure to Y2K issues.  Phase II was the development and  implementation of
action  plans  for  Y2K  compliance.  Phase  III was the  final  testing  of the
appropriate major areas of exposure to ensure compliance.

            All three phases were completed by December 31, 1999, and to January
14, 2000,  the Company is not aware of any  significant  problems,  or financial
losses, associated with Y2K issues.

            Given the short  period of time that has elapsed  post  December 31,
1999,  it is possible  that the Company and its major vendors might not have yet
identified or become aware of some Y2K issues and the related implications.

            While we believe the  identification  of  significant  Y2K issues is
unlikely at this time, a possible  worst case scenario might include (a) delays,
inaccuracies or other difficulties with respect to billing customers or the loss
of customer records, (b) our inability to run one or more of our incinerators or
recycling  facilities,  (c) our key vendors  not being able to supply  goods and
services on a timely  basis,  and (d) the  inability  of our  customers to remit
payment for services  rendered on a timely basis. The financial impact of any or
all of the above worst case  scenarios  has not been and cannot be  estimated by
management due to the numerous  uncertainties and variables associated with such
scenarios.


                                       18
<PAGE>


                           PART II - OTHER INFORMATION

ITEM 1.  LEGAL PROCEEDINGS.

GENERAL

         The business of the Company's  hazardous and industrial  waste services
is continuously  regulated by federal,  state,  provincial and local  provisions
that have been enacted or adopted,  regulating  the discharge of materials  into
the environment or primarily for the purpose of protecting the environment.  The
nature of the Company's businesses results in its frequently becoming a party to
judicial or  administrative  proceedings  involving  all levels of  governmental
authorities and other interested parties. The issues that are involved generally
relate to  applications  for  permits  and  licenses  by the  Company  and their
conformity with legal requirements and alleged technical  violations of existing
permits and  licenses.  The Company  does not believe  that these issues will be
material to the  Company's  operations or financial  condition.  At November 30,
1999,  subsidiaries  of the Company  were  involved in four  proceedings  of the
latter type relating  primarily to activities  at waste  treatment,  storage and
disposal  facilities  where the  Company  believes  sanctions  involved  in each
instance may exceed $100,000. The Company believes that the ultimate disposition
of these issues will not have a  materially  adverse  effect upon the  Company's
consolidated financial position or results of operations.

         From time to time,  the  Company  is named as a  defendant  in  various
lawsuits  arising in the  ordinary  course of  business,  including  proceedings
wherein  persons  claim injury  resulting  from the use of the  Company's  parts
cleaner equipment and/or cleaning  products,  other matters  involving  personal
injury and property  damage claims and  employment-related  claims.  A number of
such legal proceedings are currently pending in various courts and jurisdictions
throughout North America.  Based on the Company's assessment of known claims and
its historical claims payment pattern, and discussions with internal and outside
legal counsel and risk management personnel,  the Company believes that there is
no proceeding  pending against the Company  relating to such matters arising out
of the ordinary course of business that, if resolved against the Company,  would
have a  materially  adverse  effect upon the  Company's  consolidated  financial
position or results of operations.

         In the United States, CERCLA imposes financial liability on persons who
are  responsible for the release of hazardous  substances into the  environment.
Present  and  past  owners  and  operators  of  sites  which  release  hazardous
substances,  as well as generators and  transporters of the waste material,  are
jointly and severally liable for remediation costs and environmental  damage. At
November  30,  1999,  the Company had been  notified  that it was a  potentially
responsible  party  in  connection  with 49  locations  in its  hazardous  waste
management and other businesses. The Company continually reviews its status with
respect to each  location  and the  extent of its  alleged  contribution  to the
volume of waste at the location,  the available evidence  connecting the Company
to that location,  and the numbers and financial  soundness of other potentially
responsible parties at the location. Based upon presently available information,
the  Company  does not  believe  that  potential  liabilities  arising  from its
involvement with these locations will be material to the Company's operations or
financial condition.



                                       19
<PAGE>



LAMBTON HAZARDOUS WASTE LANDFILL, ONTARIO, CANADA

         On September 3, 1999, The Company's  Lambton  hazardous  waste landfill
facility in Ontario,  Canada (the "Facility"),  discovered an upwelling of water
and natural gas in a disposal cell designated as Sub-cell 3. While in the course
of trying to  determine  the  source  and cause of the  upwelling,  the  Company
informed  the  Ontario  Ministry  of  Environment  and  Energy  ("MOE")  of  the
situation. On November 2, 1999, MOE issued a Field Order finding that the upward
migration  of water and methane gas onto the  landfill  cell floor  necessitated
that the  Company  not  utilize  the  newly  constructed  Sub-cell  3 for  waste
disposal.  On December  14, 1999 the MOE issued a second  Field Order  requiring
that  Sub-cell 4,  another  newly  constructed  cell,  not be utilized for waste
disposal after MOE officials  observed what they believed to be significant  gas
evolution  from the  bottom  of the  cell.  On  December  21,  1999  independent
technical  experts and Company  professionals  presented to MOE  testimony and a
report  addressing MOE concerns.  Following the hearing and  testimony,  the MOE
issued a third Field Order on December 24, 1999 revoking the two previous orders
and  allowing  the  utilization  of  Sub-Cell  4 for  waste  disposal  under new
conditions  which  included  that;  (1) no waste in  Sub-Cell 4 was to be placed
below an  elevation  of 182 meters  above mean sea level and (2) with respect to
Sub-Cell 3 the Company will provide a report for the approval of the Director of
the MOE which provides the plan for identifying potential areas of gas and water
venting,  the proposed  measures to remediate all areas  identified  and further
steps to protect the integrity of the sub-cell.

         These events at the Facility have  resulted in an immaterial  financial
loss due to the temporary  closure of the landfill and may result in a reduction
in cell and overall landfill  capacity which,  depending upon the level of waste
disposal at the  Facility  may (1)  decrease  operating  income  margins and (2)
require a permit expansion earlier than previously anticipated.

         Other than as herein reported there have been no additional significant
legal proceedings nor any material changes in the legal proceedings  reported in
PART II, Item 3 of the  Registrant's  Report on Form 10-K for the twelve  months
ended August 31, 1999.


ITEM 2.  CHANGES IN SECURITIES AND USE OF PROCEEDS.

         On October 5, 1999,  the Board of Directors  of the Company  declared a
dividend  distribution  of one Common Share Purchase  Right on each  outstanding
share of Common Stock  payable on or about October 25, 1999 to  shareholders  of
record on such date. For a further description of the Rights, see the Summary of
Rights to Purchase  Common  Stock which was  attached as Exhibit B to the Rights
Agreement and attached as Exhibit 1 to the Company's  Current Report on Form 8-K
filed on October 15, 1999.

ITEM 4.  SUBMISSION OF MATTERS TO A VOTE OF SECURITY HOLDERS.

         The Company's  Annual Meeting of Shareholders  was held on November 30,
1999.  At  the  meeting,  the  Company's  shareholders  (i)  elected  the  three
individuals who had been nominated to be members of the Board of Directors, (ii)
approved  an  increase  of the number of shares  available  under the 1997 stock
option plan by 1,000,000  shares;  and (iii) approved the Executive  Bonus Plan.
The following table sets forth the voting results:

                                       20
<PAGE>

                              For        Against        Withheld     Abstentions
                              ---        -------        --------     -----------
Election of Directors:

John W. Rollins, Sr.        89,253,134        N/A     1,830,632              N/A
David E. Thomas, Jr.        89,247,094        N/A     1,836,672              N/A
James R. Bullock            89,252,725        N/A     1,831,041              N/A

Employee Option Increase    84,599,137   6,200,874          N/A          283,755

Executive Bonus Plan        88,981,816   1,672,847          N/A          429,103

ITEM 6.  EXHIBITS AND REPORTS ON FORM 8-K.

     (a)   Exhibits:

     (3)(a) Restated  Certificate of  Incorporation of the Company dated May 13,
1997 and Amendment to Certificate of  Incorporation  dated May 15, 1997 filed as
Exhibit 3(a) to the  Registrant's  Form 10-Q for the Quarter  ended May 31, 1997
and incorporated herein by reference.

     (3)(a)(i) Certificate of Correction Filed to Correct a Certain Error in the
Restated and Amended  Certificate of  Incorporation of the Company dated October
15, 1997 filed as Exhibit  (3)(a)(i) to the  Registrant's  Form 10-K-405 for the
Year ended August 31, 1997, and incorporated herein by reference.

     (3)(a)(ii)   Certificate  of  Amendment  to  the  Restated  Certificate  of
Incorporation   of  the  Company  dated  November  25,  1998  filed  as  Exhibit
(3)(a)(iii)  to the  Registrant's  Form 10-Q for the quarter ended  November 30,
1998 and incorporated herein by reference.

     (3)(a)(iii)  Certificate  of  Amendment  to  the  Restated  Certificate  of
Incorporation of the Company dated November 30, 1998 filed as Exhibit (3)(a)(iv)
to the  Registrant's  Form 10-Q for the  quarter  ended  November  30,  1998 and
incorporated herein by reference.

     (3)(b) Amended and Restated Bylaws of the Company filed as Exhibit 4(ii) to
the Registrant's Current Report on Form 8-K dated July 29, 1997 and incorporated
herein by reference.

     (4)(a)  Indenture  dated as of May 29, 1998 between LES, Inc. (a subsidiary
of the Registrant),  Registrant, subsidiary guarantors of the Registrant and The
Bank of Nova Scotia Trust  Company of New York, as trustee filed as Exhibit 4(b)
to the Registrant's Form S-4 Registration Statement No. 333-57587 filed June 24,
1998 and incorporated herein by reference.

     (4)(b) First Supplemental Indenture effective as of November 15, 1998 among
Safety-Kleen Services, Inc. the Registrant, SK Europe, Inc. and The Bank of Nova
Scotia  Trust  Company of New York,  as trustee  filed as Exhibit  (4)(f) to the
Registrant's  Form S-4 Registration  Statement No. 333-82689 filed July 12, 1999
and incorporated herein by reference.

     (4)(c)  Indenture dated as of May 17, 1999 between  Registrant and the Bank
of Nova Scotia Trust Company of New York, as trustee filed as Exhibit  (4)(b) to
the Registrant's  Form S-4  Registration

                                       21
<PAGE>

Statement No. 333-82689 filed July 12,1999 and incorporated herein by reference.

     (4)(d)  Second  Supplemental  Indenture  effective  as of May 7, 1999 among
Safety-Kleen  Services,  Inc. the  Registrant,  SK Services,  L.C.,  SK Services
(East),  L.C. and The Bank of Nova Scotia Trust  Company of New York, as trustee
filed as Exhibit (4)(d) to the Registrant's Form 10-K filed October 29, 1999 and
incorporated herein by reference.

     (4)(e)  Registration  Rights  Agreement  dated as of May 17,  1999  between
Registrant and TD Securities,  NationsBanc Montgomery Securities LLC and Raymond
James & Associates,  Inc. filed as Exhibit (4)(a) to the  Registrant's  Form S-4
Registration Statement No. 333-82689 filed July 12, 1999 and incorporated herein
by reference.

     (4)(f)  Amended and Restated  Credit  Agreement  among Laidlaw  Chem-Waste,
Inc.,  Laidlaw  Environmental  Services (Canada) Ltd.,  Toronto Dominion (Texas)
Inc.,  The  Toronto-Dominion  Bank, TD Securities  (USA) Inc.,  The Bank of Nova
Scotia,   NationsBank,   N.A.  and  The  First  National  Bank  of  Chicago  and
NationsBank,  N.A.  as  Syndication  Agent  dated as of April 3, 1998,  filed as
Exhibit 4(f) to the  Registrant's  Form 10-Q for the quarter ended  February 28,
1999, and incorporated herein by reference.

     (4)(g)  Supplement  to the  Amended and  Restated  Credit  Agreement  among
Laidlaw Chem-Waste,  Inc., Laidlaw Environmental Services (Canada) Ltd., Toronto
Dominion (Texas) Inc., The Toronto-Dominion  Bank, TD Securities (USA) Inc., The
Bank of Nova Scotia,  NationsBank,  N.A. and The First  National Bank of Chicago
and NationsBank,  N.A. as Syndication  Agent dated as of April 3, 1998, filed as
Exhibit 4(e) to a subsidiary of the Registrant's Form S-4 Registration Statement
No. 333-57587 filed June 24, 1998 and incorporated herein by reference.

     (4)(h)  Waiver and First  Amendment  to the  Amended  and  Restated  Credit
Agreement  dated as of May 15,  1998  among  LES,  Inc.,  Laidlaw  Environmental
Services (Canada) Ltd., the Lenders, Toronto Dominion (Texas), Inc., The Toronto
Dominion Bank, TD Securities  (USA) Inc., The Bank of Nova Scotia,  NationsBank,
N.A., The First National Bank of Chicago and Wachovia Bank filed as Exhibit 4(f)
to a  subsidiary  of  the  Registrant's  Form  S-4  Registration  Statement  No.
333-57587 filed June 24, 1998 and incorporated herein by reference.

     (4)(i) Commitment to Increase Supplement to the Amended and Restated Credit
Agreement  dated as of June 3,  1998  among  LES,  Inc.,  Laidlaw  Environmental
Services (Canada) Ltd., the Lenders, Toronto Dominion (Texas), Inc., The Toronto
Dominion Bank, TD Securities  (USA) Inc., The Bank of Nova Scotia,  NationsBank,
N.A., The First National Bank of Chicago and Wachovia Bank filed as Exhibit 4(g)
to a  subsidiary  of  the  Registrant's  Form  S-4  Registration  Statement  No.
333-57587 filed June 24, 1998 and incorporated herein by reference.

     (4)(j) Second  Amendment to the Amended and Restated Credit Agreement dated
as of November 20, 1998 among  Safety-Kleen  Services,  Inc.  (formerly known as
LES,  Inc.),  Safety-Kleen  Services  (Canada) Ltd.  (formerly  known as Laidlaw
Environmental  Services  (Canada) Ltd.), the Lenders,  Toronto Dominion (Texas),
Inc.,  The Toronto  Dominion  Bank, TD Securities  (USA) Inc.,  The Bank of Nova
Scotia, NationsBank,  N.A., The First National Bank of Chicago and Wachovia Bank
N.A.,  filed as Exhibit  (4)(j) to the  Registrant's  Form 10-Q for the  quarter
ended February 28,

                                       22
<PAGE>

1999 and incorporated herein by reference.

     (4)(k)  Waiver and Third  Amendment  to the  Amended  and  Restated  Credit
Agreement dated as of May 6, 1999 among  Safety-Kleen  Services,  Inc. (formerly
known as LES,  Inc.),  Safety-Kleen  Services  (Canada) Ltd.  (formerly known as
Laidlaw  Environmental  Services  (Canada) Ltd.), the Lenders,  Toronto Dominion
(Texas),  Inc., The Toronto Dominion Bank, TD Securities (USA) Inc., The Bank of
Nova Scotia, NationsBank,  N.A., The First National Bank of Chicago and Wachovia
Bank N.A.  filed as Exhibit  (4)(l) to the  Registrant's  Form S-4  Registration
Statement  No.  333-82689  filed  July  12,  1999  and  incorporated  herein  by
reference.

     (4)(l) Registration Rights Agreement dated May 15, 1997 between Registrant,
Laidlaw  Transportation,  Inc.  and Laidlaw  Inc. the form of which was filed as
Exhibit B to Annex A to the Registrant's  Definitive Proxy Statement on Form DEF
14A, filed on May 1, 1997 and incorporated herein by reference.

     (4)(m) Indenture dated as of May 1, 1993 between the Industrial Development
Board  of  the   Metropolitan   Government  of  Nashville  and  Davidson  County
(Tennessee)  and  NationsBank of Tennessee,  N.A.,  filed as Exhibit 4(f) to the
Registrant's  Form 10-Q for the Quarter  ended May 31,  1997,  and  incorporated
herein by reference.

     (4)(n) Indenture of Trust dated as of August 1, 1995 between Tooele County,
Utah and West One Bank,  Utah,  now known as U.S.  Bank,  as  Trustee,  filed as
Exhibit 4(h) to the  Registrant's  form 10-Q for the Quarter ended May 31, 1997,
and incorporated herein by reference.

     (4)(o)  Indenture of Trust dated as of July 1, 1997 between  Carbon County,
Utah and U.S. Bank, a national banking association, as Trustee, filed as Exhibit
4(i) to the  Registrant's  Form 10-Q for the  Quarter  ended May 31,  1997,  and
incorporated herein by reference.

     (4)(p)  Indenture of Trust dated as of July 1, 1997 between  Tooele County,
Utah and U.S. Bank, a national banking association, as Trustee, filed as Exhibit
4(j) to the  Registrant's  Form 10-Q for the  Quarter  ended May 31,  1997,  and
incorporated herein by reference.

     (4)(q)  Indenture  of Trust  dated as of July 1,  1997  between  California
Pollution  Control  Financing  Authority  and  U.S.  Bank,  a  national  banking
association, as Trustee, filed as Exhibit 4(k) to the Registrant's Form 10-Q for
the Quarter ended May 31, 1997, and incorporated herein by reference.

     (4)(r)  Promissory  Note  dated  May 15,  1997  for  $60,000,000  from  the
Registrant to Westinghouse  Electric  Corporation,  filed as Exhibit 4(n) to the
Registrant's  Form 10-Q for the Quarter  ended May 31,  1997,  and  incorporated
herein by reference.

     (4)(s)  Letter  dated May 7, 1999 from  Toronto-Dominion  (Texas)  Inc. (as
assignee of Westinghouse  Electric  Corporation) and agreed to by the Registrant
and Laidlaw Inc.  amending the terms of the  Promissory  Note dated May 15, 1997
(as referenced in Exhibit  (4)(r)) filed as Exhibit  (4)(u) to the  Registrant's
Form  S-4  Registration   Statement  No.  333-82689  filed  July  12,  1999  and
incorporated herein by reference.

                                       23
<PAGE>

     (4)(t)   Guaranty   Agreement  dated  May  15,  1997  by  Laidlaw  Inc.  to
Westinghouse  Electric  Corporation  guaranteeing  Promissory Note dated May 15,
1997 (as referenced in Exhibit (4)(s)) from Registrant to Westinghouse  Electric
Corporation),  filed  as  Exhibit  4(o) to the  Registrant's  Form  10-Q for the
Quarter ended May 31, 1997, and incorporated herein by reference.

     (4)(u) Collateral Account Pledge and Security Agreement dated as of May 17,
1999 between the Registrant,  the Bank of Nova Scotia Trust Company of New York,
as escrow  agent  and the Bank of Nova  Scotia  Trust  Company  of New York,  as
trustee,  filed as  Exhibit  (4)(d) to the  Registrant's  Form S-4  Registration
Statement  No.  333-82689  filed  July  12,  1999  and  incorporated  herein  by
reference.

     (4)(v)  Registration  Rights Agreement dated as of October 15, 1999 between
the Registrant  and EquiServe  Trust  Company,  N.A., as Rights Agent,  filed as
Exhibit (c)1 to the Registrant's Current Report on Form 8-K filed on October 15,
1999 and incorporated herein by reference.

     (4)(w) Other  instruments  defining the rights of holders of  nonregistered
debt of the  Registrant  have been  omitted  from this  exhibit list because the
amount of debt  authorized  under any such instrument does not exceed 10% of the
total assets of the Registrant and its  subsidiaries.  The Registrant  agrees to
furnish a copy of any such instrument to the Commission upon request.

     (10)(a)  Agreement  and Plan of Merger  dated as of March  16,  1998 by and
among  Registrant,  LES Acquisition,  Inc., and Safety-Kleen  Corp.  included as
Annex A of  Safety-Kleen's  Revised  Amended  Prospectus  on Form 14D-9 filed as
Exhibit 62 to  Safety-Kleen's  Amendment  No. 28 to Schedule  14-9A on March 17,
1998, and incorporated herein by reference.

     (10)(b) Stock Purchase Agreement between Westinghouse  Electric Corporation
(Seller) and Rollins Environmental Services, Inc. (Buyer) for National Electric,
Inc. dated March 7, 1995 filed as Exhibit 2 to the  Registrant's  Current Report
on Form 8-K filed on June 13, 1995 and incorporated herein by reference.

     (10)(c)  Second  Amendment to Stock  Purchase  Agreement (as  referenced in
Exhibit  (10)(b)  above),  dated  May  15,  1997  among  Westinghouse   Electric
Corporation,  Rollins  Environmental  Services,  Inc. and Laidlaw Inc., filed as
Exhibit 4(m) to the  Registrant's  Form 10-Q for the Quarter ended May 31, 1997,
and incorporated herein by reference.

     (10)(d) Rollins  Environmental  Services,  Inc. 1982 Incentive Stock Option
Plan filed with  Amendment  No. 1 to the  Company's  Registration  Statement No.
2-84139 on Form S-1 dated June 24, 1983 and incorporated herein by reference.

     (10)(e) Rollins Environmental  Services,  Inc. 1993 Stock Option Plan filed
with the Company's Proxy  Statement for the Annual Meeting of Shareholders  held
January 28, 1994 and incorporated herein by reference.

     (10)(f)  Registrant's  1997 Stock Option Plan,  filed as Exhibit 4.4 to the
Company's  Registration  Statement No.  333-41859 on Form S-8 dated December 10,
1997 and incorporated herein by reference.

                                       24
<PAGE>

     (10)(g) First Amendment to Registrant's 1997 Stock Option Plan.

     (10)(h) Registrant's  Director's Stock Option Plan, filed as Exhibit 4.5 to
the Company's  Registration  Statement No.  333-41859 on Form S-8 dated December
10, 1997 and incorporated herein by reference.

     (10)(i) First Amendment to Registrant's Director's Stock Option Plan.

     (10)(j)  Stock  Purchase   Agreement  dated  February  6,  1997  among  the
Registrant, Laidlaw Inc., and Laidlaw Transportation, Inc. filed as Exhibit A to
Annex A to the Definitive  Proxy  Statement on Form DEF 14A filed on May 1, 1997
and incorporated herein by reference.

     (10)(k)  Executive  Bonus Plan for fiscal  year 2000 filed as Appendix C to
the  Definitive  Proxy  Statement  on Form DEF 14A filed on October 29, 1999 and
incorporated herein by reference.

     (10)(l) Registrant's U.S.  Supplemental  Executive Retirement Plan filed as
Exhibit 10(g) to the Registrant's  10-Q for the quarter ended November 30, 1997,
and incorporated herein by reference.

     (10)(m) Form of Change of Control Agreement COCA.

     (10)(n) Form of Change of Control Agreement A1RBCOC.

     (10)(o) Form of Change of Control Agreement A1RMCOC.

     (10)(p) Form of Change of Control Agreement COCB.

     (10)(q) Form of Change of Control Agreement COCC.

     (10)(r) Form of Change of Control Agreement A2COC.

     (11) Statement of Computation of Per Share Earnings

     (12) Statement Re: Computation of Ratios.

     (27) Financial Data Schedule.

          (b) Reports on Form 8-K.

               i.   The Company filed a Current  Report on Form 8-K on September
                    13,  1999,  which  contained  Item 5 related to the  Company
                    announcing  that  it had  been  advised  that  Laidlaw  Inc.
                    planned to actively seek a buyer for its 44% interest in the
                    Company.

               ii.  The Company filed a Current  Report on Form 8-K on September
                    14,  1999  which  contained  Item 5 related  to the  Company
                    announcing  that the Board of Directors  appointed a Special

                                       25
<PAGE>

                    Committee  of   non-Laidlaw   Inc.   directors  to  consider
                    implications of the announced  change in Laidlaw Inc.'s time
                    horizon for divesting its 44% common shares of the Company.

               iii. The Company filed a Current Report on Form 8-K on October 6,
                    1999  which   contained   Item  5  related  to  the  Company
                    announcing its operating  results for the fourth quarter and
                    fiscal year ending August 31, 1999.

               iv.  The  Company  filed a Current  Report on Form 8-K on October
                    12, 1999 which  contained Item 5 announcing that the Company
                    received  detailed report from its Special Committee and its
                    financial advisor, Raymond James and Associates on strategic
                    and financial alternatives for the Company.

               v.   The  Company  filed a Current  Report on Form 8-K on October
                    15, 1999 which contained Item 5 announcing that the Board of
                    Directors of the Company declared a dividend distribution of
                    1 common share purchase right on each  outstanding  share of
                    common  stock  payable  on or  about  October  25,  1999  to
                    shareholders of record on such date.



                                       26
<PAGE>



                                  EXHIBIT INDEX

         (a)     Exhibits:

     (3)(a) Restated  Certificate of  Incorporation of the Company dated May 13,
1997 and Amendment to Certificate of  Incorporation  dated May 15, 1997 filed as
Exhibit 3(a) to the  Registrant's  Form 10-Q for the Quarter  ended May 31, 1997
and incorporated herein by reference.

     (3)(a)(i) Certificate of Correction Filed to Correct a Certain Error in the
Restated and Amended  Certificate of  Incorporation of the Company dated October
15, 1997 filed as Exhibit  (3)(a)(i) to the  Registrant's  Form 10-K-405 for the
Year ended August 31, 1997, and incorporated herein by reference.

     (3)(a)(ii)   Certificate  of  Amendment  to  the  Restated  Certificate  of
Incorporation   of  the  Company  dated  November  25,  1998  filed  as  Exhibit
(3)(a)(iii)  to the  Registrant's  Form 10-Q for the quarter ended  November 30,
1998 and incorporated herein by reference.

     (3)(a)(iii)  Certificate  of  Amendment  to  the  Restated  Certificate  of
Incorporation of the Company dated November 30, 1998 filed as Exhibit (3)(a)(iv)
to the  Registrant's  Form 10-Q for the  quarter  ended  November  30,  1998 and
incorporated herein by reference.

     (3)(b) Amended and Restated Bylaws of the Company filed as Exhibit 4(ii) to
the Registrant's Current Report on Form 8-K dated July 29, 1997 and incorporated
herein by reference.

     (4)(a)  Indenture  dated as of May 29, 1998 between LES, Inc. (a subsidiary
of the Registrant),  Registrant, subsidiary guarantors of the Registrant and The
Bank of Nova Scotia Trust  Company of New York, as trustee filed as Exhibit 4(b)
to the Registrant's Form S-4 Registration Statement No. 333-57587 filed June 24,
1998 and incorporated herein by reference.

     (4)(b) First Supplemental Indenture effective as of November 15, 1998 among
Safety-Kleen Services, Inc. the Registrant, SK Europe, Inc. and The Bank of Nova
Scotia  Trust  Company of New York,  as trustee  filed as Exhibit  (4)(f) to the
Registrant's  Form S-4 Registration  Statement No. 333-82689 filed July 12, 1999
and incorporated herein by reference.

     (4)(c)  Indenture dated as of May 17, 1999 between  Registrant and the Bank
of Nova Scotia Trust Company of New York, as trustee filed as Exhibit  (4)(b) to
the Registrant's  Form S-4  Registration  Statement No. 333-82689 filed July 12,
1999 and incorporated herein by reference.

     (4)(d)  Second  Supplemental  Indenture  effective  as of May 7, 1999 among
Safety-Kleen  Services,  Inc. the  Registrant,  SK Services,  L.C.,  SK Services
(East),  L.C. and The

                                       27
<PAGE>

Bank of Nova  Scotia  Trust  Company of New York,  as  trustee  filed as Exhibit
(4)(d) to the  Registrant's  Form 10-K filed  October 29, 1999 and  incorporated
herein by reference.

     (4)(e)  Registration  Rights  Agreement  dated as of May 17,  1999  between
Registrant and TD Securities,  NationsBanc Montgomery Securities LLC and Raymond
James & Associates,  Inc. filed as Exhibit (4)(a) to the  Registrant's  Form S-4
Registration Statement No. 333-82689 filed July 12, 1999 and incorporated herein
by reference.

     (4)(f)  Amended and Restated  Credit  Agreement  among Laidlaw  Chem-Waste,
Inc.,  Laidlaw  Environmental  Services (Canada) Ltd.,  Toronto Dominion (Texas)
Inc.,  The  Toronto-Dominion  Bank, TD Securities  (USA) Inc.,  The Bank of Nova
Scotia,   NationsBank,   N.A.  and  The  First  National  Bank  of  Chicago  and
NationsBank,  N.A.  as  Syndication  Agent  dated as of April 3, 1998,  filed as
Exhibit 4(f) to the  Registrant's  Form 10-Q for the quarter ended  February 28,
1999, and incorporated herein by reference.

     (4)(g)  Supplement  to the  Amended and  Restated  Credit  Agreement  among
Laidlaw Chem-Waste,  Inc., Laidlaw Environmental Services (Canada) Ltd., Toronto
Dominion (Texas) Inc., The Toronto-Dominion  Bank, TD Securities (USA) Inc., The
Bank of Nova Scotia,  NationsBank,  N.A. and The First  National Bank of Chicago
and NationsBank,  N.A. as Syndication  Agent dated as of April 3, 1998, filed as
Exhibit 4(e) to a subsidiary of the Registrant's Form S-4 Registration Statement
No. 333-57587 filed June 24, 1998 and incorporated herein by reference.

     (4)(h)  Waiver and First  Amendment  to the  Amended  and  Restated  Credit
Agreement  dated as of May 15,  1998  among  LES,  Inc.,  Laidlaw  Environmental
Services (Canada) Ltd., the Lenders, Toronto Dominion (Texas), Inc., The Toronto
Dominion Bank, TD Securities  (USA) Inc., The Bank of Nova Scotia,  NationsBank,
N.A., The First National Bank of Chicago and Wachovia Bank filed as Exhibit 4(f)
to a  subsidiary  of  the  Registrant's  Form  S-4  Registration  Statement  No.
333-57587 filed June 24, 1998 and incorporated herein by reference.

     (4)(i) Commitment to Increase Supplement to the Amended and Restated Credit
Agreement  dated as of June 3,  1998  among  LES,  Inc.,  Laidlaw  Environmental
Services (Canada) Ltd., the Lenders, Toronto Dominion (Texas), Inc., The Toronto
Dominion Bank, TD Securities  (USA) Inc., The Bank of Nova Scotia,  NationsBank,
N.A., The First National Bank of Chicago and Wachovia Bank filed as Exhibit 4(g)
to a  subsidiary  of  the  Registrant's  Form  S-4  Registration  Statement  No.
333-57587 filed June 24, 1998 and incorporated herein by reference.

     (4)(j) Second  Amendment to the Amended and Restated Credit Agreement dated
as of November 20, 1998 among  Safety-Kleen  Services,  Inc.  (formerly known as
LES,  Inc.),  Safety-Kleen  Services  (Canada) Ltd.  (formerly  known as Laidlaw
Environmental  Services  (Canada) Ltd.), the Lenders,  Toronto Dominion (Texas),
Inc.,  The Toronto  Dominion  Bank, TD Securities  (USA) Inc.,  The Bank of Nova

                                       28
<PAGE>

Scotia, NationsBank,  N.A., The First National Bank of Chicago and Wachovia Bank
N.A.,  filed as Exhibit  (4)(j) to the  Registrant's  Form 10-Q for the  quarter
ended February 28, 1999 and incorporated herein by reference.

     (4)(k)  Waiver and Third  Amendment  to the  Amended  and  Restated  Credit
Agreement dated as of May 6, 1999 among  Safety-Kleen  Services,  Inc. (formerly
known as LES,  Inc.),  Safety-Kleen  Services  (Canada) Ltd.  (formerly known as
Laidlaw  Environmental  Services  (Canada) Ltd.), the Lenders,  Toronto Dominion
(Texas),  Inc., The Toronto Dominion Bank, TD Securities (USA) Inc., The Bank of
Nova Scotia, NationsBank,  N.A., The First National Bank of Chicago and Wachovia
Bank N.A.  filed as Exhibit  (4)(l) to the  Registrant's  Form S-4  Registration
Statement  No.  333-82689  filed  July  12,  1999  and  incorporated  herein  by
reference.

     (4)(l) Registration Rights Agreement dated May 15, 1997 between Registrant,
Laidlaw  Transportation,  Inc.  and Laidlaw  Inc. the form of which was filed as
Exhibit B to Annex A to the Registrant's  Definitive Proxy Statement on Form DEF
14A, filed on May 1, 1997 and incorporated herein by reference.

     (4)(m) Indenture dated as of May 1, 1993 between the Industrial Development
Board  of  the   Metropolitan   Government  of  Nashville  and  Davidson  County
(Tennessee)  and  NationsBank of Tennessee,  N.A.,  filed as Exhibit 4(f) to the
Registrant's  Form 10-Q for the Quarter  ended May 31,  1997,  and  incorporated
herein by reference.

     (4)(n) Indenture of Trust dated as of August 1, 1995 between Tooele County,
Utah and West One Bank,  Utah,  now known as U.S.  Bank,  as  Trustee,  filed as
Exhibit 4(h) to the  Registrant's  form 10-Q for the Quarter ended May 31, 1997,
and incorporated herein by reference.

     (4)(o)  Indenture of Trust dated as of July 1, 1997 between  Carbon County,
Utah and U.S. Bank, a national banking association, as Trustee, filed as Exhibit
4(i) to the  Registrant's  Form 10-Q for the  Quarter  ended May 31,  1997,  and
incorporated herein by reference.

     (4)(p)  Indenture of Trust dated as of July 1, 1997 between  Tooele County,
Utah and U.S. Bank, a national banking association, as Trustee, filed as Exhibit
4(j) to the  Registrant's  Form 10-Q for the  Quarter  ended May 31,  1997,  and
incorporated herein by reference.

     (4)(q)  Indenture  of Trust  dated as of July 1,  1997  between  California
Pollution  Control  Financing  Authority  and  U.S.  Bank,  a  national  banking
association, as Trustee, filed as Exhibit 4(k) to the Registrant's Form 10-Q for
the Quarter ended May 31, 1997, and incorporated herein by reference.

     (4)(r)  Promissory  Note  dated  May 15,  1997  for  $60,000,000  from  the
Registrant to Westinghouse  Electric  Corporation,  filed as Exhibit 4(n) to the
Registrant's  Form 10-Q for the Quarter  ended May 31,  1997,  and  incorporated
herein by reference.

                                       29
<PAGE>

     (4)(s)  Letter  dated May 7, 1999 from  Toronto-Dominion  (Texas)  Inc. (as
assignee of Westinghouse  Electric  Corporation) and agreed to by the Registrant
and Laidlaw Inc.  amending the terms of the  Promissory  Note dated May 15, 1997
(as referenced in Exhibit  (4)(r)) filed as Exhibit  (4)(u) to the  Registrant's
Form  S-4  Registration   Statement  No.  333-82689  filed  July  12,  1999  and
incorporated herein by reference.

     (4)(t)   Guaranty   Agreement  dated  May  15,  1997  by  Laidlaw  Inc.  to
Westinghouse  Electric  Corporation  guaranteeing  Promissory Note dated May 15,
1997 (as referenced in Exhibit (4)(s)) from Registrant to Westinghouse  Electric
Corporation),  filed  as  Exhibit  4(o) to the  Registrant's  Form  10-Q for the
Quarter ended May 31, 1997, and incorporated herein by reference.

     (4)(u) Collateral Account Pledge and Security Agreement dated as of May 17,
1999 between the Registrant,  the Bank of Nova Scotia Trust Company of New York,
as escrow  agent  and the Bank of Nova  Scotia  Trust  Company  of New York,  as
trustee,  filed as  Exhibit  (4)(d) to the  Registrant's  Form S-4  Registration
Statement  No.  333-82689  filed  July  12,  1999  and  incorporated  herein  by
reference.

     (4)(v)  Registration  Rights Agreement dated as of October 15, 1999 between
the Registrant  and EquiServe  Trust  Company,  N.A., as Rights Agent,  filed as
Exhibit (c)1 to the Registrant's Current Report on Form 8-K filed on October 15,
1999 and incorporated herein by reference.

     (4)(w) Other  instruments  defining the rights of holders of  nonregistered
debt of the  Registrant  have been  omitted  from this  exhibit list because the
amount of debt  authorized  under any such instrument does not exceed 10% of the
total assets of the Registrant and its  subsidiaries.  The Registrant  agrees to
furnish a copy of any such instrument to the Commission upon request.

     (10)(a)  Agreement  and Plan of Merger  dated as of March  16,  1998 by and
among  Registrant,  LES Acquisition,  Inc., and Safety-Kleen  Corp.  included as
Annex A of  Safety-Kleen's  Revised  Amended  Prospectus  on Form 14D-9 filed as
Exhibit 62 to  Safety-Kleen's  Amendment  No. 28 to Schedule  14-9A on March 17,
1998, and incorporated herein by reference.

     (10)(b) Stock Purchase Agreement between Westinghouse  Electric Corporation
(Seller) and Rollins Environmental Services, Inc. (Buyer) for National Electric,
Inc. dated March 7, 1995 filed as Exhibit 2 to the  Registrant's  Current Report
on Form 8-K filed on June 13, 1995 and incorporated herein by reference.

     (10)(c)  Second  Amendment to Stock  Purchase  Agreement (as  referenced in
Exhibit  (10)(b)  above),  dated  May  15,  1997  among  Westinghouse   Electric
Corporation,  Rollins  Environmental  Services,  Inc. and Laidlaw Inc., filed as
Exhibit 4(m) to the  Registrant's  Form 10-Q for the Quarter ended May 31, 1997,
and incorporated herein by reference.

                                       30
<PAGE>

     (10)(d) Rollins  Environmental  Services,  Inc. 1982 Incentive Stock Option
Plan filed with  Amendment  No. 1 to the  Company's  Registration  Statement No.
2-84139 on Form S-1 dated June 24, 1983 and incorporated herein by reference.

     (10)(e) Rollins Environmental  Services,  Inc. 1993 Stock Option Plan filed
with the Company's Proxy  Statement for the Annual Meeting of Shareholders  held
January 28, 1994 and incorporated herein by reference.

     (10)(f)  Registrant's  1997 Stock Option Plan,  filed as Exhibit 4.4 to the
Company's  Registration  Statement No.  333-41859 on Form S-8 dated December 10,
1997 and incorporated herein by reference.

     (10)(g) First Amendment to the 1997 Stock Option Plan.

     (10)(h) Registrant's  Director's Stock Option Plan, filed as Exhibit 4.5 to
the Company's  Registration  Statement No.  333-41859 on Form S-8 dated December
10, 1997 and incorporated herein by reference.

     (10)(i) First Amendment to the 1997 Director's Stock Option Plan.

     (10)(j)  Stock  Purchase   Agreement  dated  February  6,  1997  among  the
Registrant, Laidlaw Inc., and Laidlaw Transportation, Inc. filed as Exhibit A to
Annex A to the Definitive  Proxy  Statement on Form DEF 14A filed on May 1, 1997
and incorporated herein by reference.

     (10)(k)  Executive  Bonus Plan for fiscal  year 2000 filed as Appendix C to
the  Definitive  Proxy  Statement on Form DEF 14A filed on November 30, 1999 and
incorporated herein by reference.

     (10)(l) Registrant's U.S.  Supplemental  Executive Retirement Plan filed as
Exhibit 10(g) to the Registrant's  10-Q for the quarter ended November 30, 1997,
and incorporated herein by reference.

     (10)(m) Form of Change of Control Agreement COCA.

     (10)(n) Form of Change of Control Agreement A1RBCOC.

     (10)(o) Form of Change of Control Agreement A1RMCOC.

     (10)(p) Form of Change of Control Agreement COCB.

     (10)(q) Form of Change of Control Agreement COCC.

     (10)(r) Form of Change of Control Agreement A2COC.

                                       31
<PAGE>

     (11) Statement of Computation of Per Share Earnings

     (12) Statement Re: Computation of Ratios.

     (27) Financial Data Schedule.

          (b)  Reports on Form 8-K.

               i.   The Company filed a Current  Report on Form 8-K on September
                    13,  1999,  which  contained  Item 5 related to the  Company
                    announcing  that  it had  been  advised  that  Laidlaw  Inc.
                    planned to actively seek a buyer for its 44% interest in the
                    Company.

               ii.  The Company filed a Current  Report on Form 8-K on September
                    14,  1999  which  contained  Item 5 related  to the  Company
                    announcing  that the Board of Directors  appointed a Special
                    Committee  of   non-Laidlaw   Inc.   directors  to  consider
                    implications of the announced  change in Laidlaw Inc.'s time
                    horizon for divesting its 44% common shares of the Company.

               iii. The Company filed a Current Report on Form 8-K on October 6,
                    1999  which   contained   Item  5  related  to  the  Company
                    announcing its operating  results for the fourth quarter and
                    fiscal year ending August 31, 1999.  iv. The Company filed a
                    Current  Report  on  Form  8-K on  October  12,  1999  which
                    contained  Item  5  announcing  that  the  Company  received
                    detailed report from its Special Committee and its financial
                    advisor,  Raymond  James and  Associates  on  strategic  and
                    financial alternatives for the Company.

               v.   The  Company  filed a Current  Report on Form 8-K on October
                    15, 1999 which contained Item 5 announcing that the Board of
                    Directors of the Company declared a dividend distribution of
                    1 common share purchase right on each  outstanding  share of
                    common  stock  payable  on or  about  October  25,  1999  to
                    shareholders of record on such date.



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<PAGE>



                                   SIGNATURES

       Pursuant to the requirements of the Securities  Exchange Act of 1934, the
Registrant  has duly  caused  this  report  to be  signed  on its  behalf by the
undersigned thereunto duly authorized.


DATE:  January 14, 2000            SAFETY-KLEEN CORP.
                                   (Registrant)

                                   /s/Kenneth W. Winger
                                   ---------------------------------
                                   Kenneth W. Winger
                                   President and Chief Executive Officer



                                   /s/Paul R. Humphreys
                                   ---------------------------------
                                   Paul R. Humphreys
                                   Senior Vice President-Finance and
                                   Chief Financial Officer





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