EXHIBIT 5


                              [SAFETY-KLEEN LOGO]



Dear Safety-Kleen Shareholder:

     We, the Board of Directors, realize the enormous responsibility of
evaluating the offers for your Company.  We believe that the $27 all-cash merger
agreement we have approved (the "Philip Merger") offers Safety-Kleen
shareholders value superior to the Laidlaw Environmental proposal.  The Philip
Merger Agreement was entered into after your Board carefully evaluated the risks
and benefits of the alternatives available and unanimously agreed the Philip
Merger Agreement is in the best interests of the shareholders and other
constituencies which your Board considered.

     Laidlaw Environmental Services claims that the offer it made on November 20
is worth $30 per share, consisting of $15 in Laidlaw Environmental stock and $15
cash, subject to certain adjustments.  We firmly believe that it is not worth
$30 per share.

 . The stock portion of their offer is uncertain and could be worth significantly
less than its claimed $15 value.  Consider the following:

     - Laidlaw says it expects to achieve an estimated $100-130 million of
     "synergies".  However, there is little overlap between Safety-Kleen's core
     service business and Laidlaw's landfill and incineration business.  As a
     result, we do not believe that Laidlaw can accomplish even $50 million of
     synergies without significant reductions in service quality, revenue and
     profit.

     - The value of the stock portion of Laidlaw Environmental's offer is
     dependent upon its stock trading above $4.29 per share.  As recently as
     last week, the stock traded below the minimum level.

     - We believe that Laidlaw Environmental has materially underestimated the
     charges for depreciation and amortization that would result from its
     transaction.  Accordingly, Laidlaw's future earnings would be significantly
     reduced.

     - Up to approximately 200 million Laidlaw Environmental shares would be
     issued in the transaction, which could quadruple the stock available in the
     public markets.  It is questionable whether the market could absorb this
     substantial stock issuance without adversely affecting Laidlaw's stock
     price.

 . Laidlaw Environmental provides no guaranty as to how much will be paid in cash
to Safety-Kleen shareholders.  The nominal $15 in cash portion is subject to
reduction, which based on Laidlaw's own estimates, could amount to between $1.28
and $2.14 per share.

 . Considering the conditions in Laidlaw's offer, it is unlikely that its
proposed transaction would close before mid-1998 at the earliest.

     Your Board also carefully considered the significant differences between
the business operations of Safety-Kleen and Laidlaw Environmental.  Safety-Kleen
recycles; Laidlaw incinerates and puts wastes in the ground.  The latter results
in much greater potential environmental liability.  As a result of the
transaction, Laidlaw, Inc., the parent company, would remove the potential
liabilities and environmental risks of Laidlaw Environmental from its balance
sheet.  Safety-Kleen shareholders, who could become owners of more than 50% of
Laidlaw Environmental if the transaction were completed, would become subject to
those risks.

 
     We have called a special meeting of shareholders to approve the Philip
Merger which will be held on February 11, 1998.  In the next few weeks, we will
forward to you proxy materials containing details on this merger.

     The Board of Directors and management team at Safety-Kleen has, and will
continue to act with your best interests in mind.  We appreciate your support
and confidence and will keep you fully informed of the process.

Sincerely,

Donald W. Brinckman
Founder, Chairman and Chief Executive Officer
For the Board of Directors