EXHIBIT 52


                     SAFETY-KLEEN IS CONVINCED LLE CANNOT
                       ACHIEVE ITS PROJECTED SYNERGIES-


The following slides contain statements of the opinion and beliefs of SK 
concerning various matters relating to the ability to achieve synergies in a 
combination of SK and LLE as follows:

 .    Off-site Hazardous Waste Management Business is Declining

 .    Safety-Kleen and LLE - Not Synergistic Businesses

 .    LLE/ Rollins "Synergies" are Not Replicable in an SK/LLE Combination

 .    LLE's Waste Internalization Program is not Feasible

 .    SK Believes: LLE Service Center Proposals Would Reduce Gross Profit

 .    Further People Cuts Would Lose Business




                      OFF-SITE HAZARDOUS WASTE MANAGEMENT
                             BUSINESS IS DECLINING

                       HAZARDOUS WASTE MANAGED OFFSITE:
                                    TRENDS

[Line graph depicting volumes of hazardous waste managed offsite using the 1989
                          volume as the basis (100%)

 
 

                                
          1989   100%             1993  142% 
          1990   120%             1994  135% 
          1991   140%             1995  130% 
          1992   150%             1996  123%  
 

Source-Farkas-Berkowitz]

 .    Market Shrink 5% per Year 1993-1996 (Farkas-Berkowitz)
 .    We believe the start up of Marine Shale's facility will result in
     substantial additional capacity and add significant competitive pressure




                      OFF-SITE HAZARDOUS WASTE MANAGEMENT
                             BUSINESS IS DECLINING


                     [Subtitle C Hazardous Waste Landfill
                    Disposal Volumes Graph Showing Volumes
                              for years 1989-1996

 
 


Source EI Digest
                             
1989   3,263,000 cu yds      1993   3,514,000 cu yds
1990   3,373,000 cu yds      1994   3,639,000 cu yds
1991   3,350,000 cu yds      1995   2,703,000 cu yds 
1992   3,481,000 cu yds      1996   2,629,000 cu yds]
 




                     OFF-SITE HAZARDOUS WASTE MANAGEMENT
                            BUSINESS IS DECLINING
                               LLE'S LIABILITIES
                              ----------------- 

 .    Government Required Closure/Post Closure Care 
     (financial assurance): $450 Million
     --includes Pinewood, S.C.: $140 Million
       (only 1 of 8 LLE hazardous waste landfills)

 .    Projected Expenditures: $280 Million

 .    Current Reserve: $183.1 Million

 .    Financial assurance is provided by Laidlaw, Inc. Will they Continue to do
     so?



                      OFF-SITE HAZARDOUS WASTE MANAGEMENT
                             BUSINESS IS DECLINING

   The hazardous waste disposal industry continues to show signs of declining
                        profitability and asset values.

 .  Waste Management last week announced $3.5 billion of special charges --
   including $2.9 billion of asset revaluation adjustments -- reducing
   shareholders' equity by more than 70%.

 .  $0.9 billion of the total charge related to its chemical and hazardous waste
   business.

 .  The asset revaluations in the hazardous waste business related primarily to
   recognizing the impaired value of its thermal, land disposal and fuels
   recycling facilities.

 .  WMX's chairman also announced they expect "declines in hazardous waste
   revenues" in their 1998 outlook.
    


                             SAFETY KLEEN AND LLE
                          NOT SYNERGISTIC BUSINESSES
                     S-K INDUSTRIAL CUSTOMER SERVICE NEEDS

[Graphical representation of Safety-Kleen industrial customer needs survey
performed mid-1997.

5,197 service needs were identified including parts cleaning, PCB's vacuum
services, empty drum service, oil services, toxic metals, acids, bases, etc.

Totals were categorized as follows:

 
 

                                            
- -- Recycle/Reuse Services                3,368   65%
- -- Compliance and Testing Services         745   14%  
- -- Onsite and Closed Loop Services         928   18%
- -- Chemical Neutralization                  89    2%
- -- Landfill Incineration                    67    1%]
 




                             SAFETY KLEEN AND LLE
                          NOT SYNERGISTIC BUSINESSES

[Graphical representation of Safety-Kleen industrial customer waste service
revenues from 1989-1997 in millions of dollars and separated by the following
waste services categories.]

 
 

                           1989      1991       1993       1995       1997
                                                     
Waste Fuel               $14.30    $20.40    $ 56.20    $ 69.80    $ 75.40

Incineration             $ 1.00    $10.50    $  7.10    $  5.60    $  3.40

Water                    $ 0.60    $ 2.80    $  8.80    $ 13.30    $ 14.60

Absorbent                $ 0.00    $ 0.70    $  3.00    $  5.90    $ 10.80

Other Serv               $ 0.00    $ 0.00    $  0.50    $  1.70    $  7.80

Tech Serv                $ 0.00    $ 0.00    $  0.00    $  0.00    $ 12.30

Parts Clean              $40.00    $97.10    $118.00    $119.00    $137.00
 


 
                        LLE/ROLLINS "SYNERGIES" ARE NOT
                      REPLICABLE IN AN SK/LLE COMBINATION

 .  Rollins was in the same business as LLE with only 3,600 customers to support.
   Rollins was a company with $240 million in fiscal 1996 revenues and over $63
   million in net losses in the 3-1/4 years prior to December 31, 1996.

 .  Rollins already had transitioned 2 incinerators out of normal service prior
   to the merger due to under-utilization. L.L.E.'s Clive incinerator was
   operating at 29% of capacity and incurred $5 million of operating losses in
   the first half of 1997. It sat within a few miles of Rollins' Aragonite
   facility. These large fixed assets were easily made redundant.

 .  L.L.E. recorded asset writedowns and reserves totaling approximately $0.5
   billion in the merger, including $0.3 billion to writedown their own
   facilities.

 .  This "accounting event" has enabled L.L.E. to reduce (non-cash) depreciation
   and amortization expense by approximately $38 million annually -- which
   represents approximately 40% of their reported $90 million in annual Rollins
   "synergies".

 .  We believe L.L.E. has exhausted its opportunities for writedowns of its
   assets to benefit earnings.





                      LLE'S WASTE INTERNALIZATION PROGRAM
                                IS NOT FEASIBLE

                      Technical Limitations of Commercial
                                 Incinerators

 .  Incinerators Limited to a Maximum Thermal Input

   -- Design and Permit Limits on Total Heat Input (Btu/hr)

   -- High Energy Value Waste Streams Displace Available 
      Capacity to Burn Low Energy Bearing Waste Streams

 .  Our review concludes that internalization of Safety-Kleen 
   Waste Volumes into Laidlaw is Clearly Not Practical

   -- S-K Waste Volumes Could Represent all of Laidlaw's
      Practical U.S. Capacity unless LLE reopens facilities they
      stated are/will be closed.

 .  We Believe Cement Kilns Provide a Significant
   Savings in Disposal Costs Compared to Incinerators:

   -- We believe S-K Disposal Costs for Bulk Liquids and
      Solids Are Less Than Incinerator Variable Costs

 .  Laidlaw Continues the Practice of Sending Blended
   Wastes as Fuel to Cement Kilns (including Holnam/S-K)




                      LLE'S WASTE INTERNALIZATION PROGRAM
                                IS NOT FEASIBLE

                  74% of Safety-Kleen's Waste is Recycled and
                          Less than 2% is Incinerated

[Graphical representation of Safety-Kleen's Waste Volumes by disposal methods.

   The four methods of disposal and the percentages are listed below.

   Recycled Products                       74%

   Energy Recovery-Cement Kilns            23%

   Incineration                           1.9%

   Other                                  1.1%]

                                 S-K BELIEVES:
                         LLE SERIVCE CENTER PROPOSALS
                           WOULD REDUCE GROSS PROFIT
                        AVERAGE BRANCH EXPENSE BY TYPE

  [Graph showing breakdown of average annual costs for Safety-Kleen branches.

The data includes ($000s)
  Materials/Disposal                            $593
  Labor/Benefits                                $1,031
  Transportation                                $301
  Equipment at Customers                        $159
  Facilities                                    $210
  Other                                         $123]

Branch sales/sevice people and trucks generate revenue of over $280,000 per
capita and waste disposal is a function of sales volume. Therefore, we believe
proposed cuts will impair revenue and profit.



                          FURTHER PEOPLE CUTS WOULD 
                                 LOSE BUSINESS

LLE proposes to eliminate at least 600 personnel --
  equivalent to all personnel in the Elgin Headquarters

This is the centralized support for:

 .  5,000,000 Customer Transactions

 .  3,600 Fleet Vehicles

 .  1,400 Railcars

 .  1,000 Environmental Inspections

 .  330,000 Vendor Invoices Processed

 .  92 Railsites

 .  21,000 Fleet Maintenance Inspections

 .  146,000 Customer Calls

 .  90,000 Telemarketing Calls




                                  CONCLUSION

                      SYNERGY SAVINGS & REVENUE REDUCTION
                    ESTIMATED 1998 EPS ACCRETION/(DILUTION)

[Table showing impact on SK/LLE combination of reduced service levels 
  resulting from various synergy levels.

- -------------------------------------------------------------------------------
Synergy Savings = $100MM                                Synergy Savings = $75MM
                                                                        
                       0%   28%                                 0%    2%
   % SK                5%    2%             % SK                5%  -24%
Sales Lost            10%  -24%          Sales Lost            10%  -50%
                      15%  -51%                                15%  -76%
                      20%  -77%                                20%  
- -------------------------------------------------------------------------------
Synergy Savings = $50MM                                 Synergy Savings = $25MM
                                                                        
                       0%  -25%                                 0%  -51%
   % SK                5%  -51%             % SK                5%  -77%
Sales Lost            10%  -77%          Sales Lost            10%  
                      15%                                      15%  
                      20%                                      20%  
- -------------------------------------------------------------------------------

("% Sales Lost" for this analysis is SK service revenue lost, with SK service
   revenue assumed to be $797.8 million, or the estimated level of service
   revenue for the LTM period ended 8/31/98. Note that service revenue excludes
   revenue from Oil Services and Europe. The related reduction in SK COGS is
   calculated assuming that the variable cost represents approximately 39% of US
   Industrial and Automotive service revenue (based on fiscal 1997 actuals).)]

                                  CONCLUSION

                         Bottom Line:  Will an LLE/SK

                          Combination Be Synergistic?

 . We believe a Laidlaw acquisition brings:

  - A declining hazardous waste disposal business to burden Safety-Kleen's 
    service and recycling business.

  - The weight and demands of $2.3 billion in debt

  - Substantial environmental remediation and closure liabilities

  - An increase in the shares and public float of stock by 270%

  - Business concern that these burdens and proposed deep cuts in people will 
    decrease productivity and financial results

  - Synergies which will be dilutive if not achieved and could impair financial 
    performance if achieved