EXHIBIT 10(o)
                                NSC CORPORATION
                              EMPLOYMENT AGREEMENT
                             EFSTATHIOS A. KOUNINIS

PERSONAL AND CONFIDENTIAL

Mr. Efstathios A. Kouninis
c/o NSC Corporation
49 Danton Drive
Methuen, MA 01844


Re:   Employment Security Agreement

Dear Stathis:

In light of the recent  developments at NSC Corporation  ("NSC"),  NSC wishes to
offer  you this  Employment  Security  Agreement  in  appreciation  of your past
dedicated service and to provide you with peace of mind.

In  consideration  of the payments and other security listed below, you agree to
continue  your  employment  with  NSC and  provide  your  full  cooperation  and
assistance to NSC.

       1.    Term.  The Term of the Agreement  shall be for a period  commencing
on the date hereof and ending on October 8, 1998.

      2.     Base Salary.  Your  current base salary will not be reduced  during
the Term and will be subject  to normal  increases  which are in the  discretion
of management.

      3. Execution  Bonus.  Upon the execution and delivery of this agreement by
you, NSC shall pay to you, in one single lump sum, a one-time execution bonus in
the amount of Fifteen Thousand ($15,000.00) Dollars.

      4.  Completion  Bonuses.  In  addition  to,  and not in lieu of, any other
incentive  compensation  which NSC may make  available  to you from time to time
during the Term,  (i) if you remain  employed with NSC through  October 8, 1997,
NSC  agrees  to pay you a  one-time  completion  bonus  in the  amount  of Seven
Thousand Five Hundred  ($7,500.00)  Dollars and (ii) if you remain employed with
NSC through the end of the Term, NSC agrees to pay to you a one-time  completion
bonus in the amount of Seven Thousand Five Hundred  ($7,500.00)  Dollars. In the
event that, prior to the  aforementioned  dates, you voluntarily  terminate your
employment with NSC, or NSC terminates your employment for Cause, you shall have
no  entitlement  to such  completion  bonuses  and  NSC  shall  have no  further
obligation with respect thereto.

      5. Stock Options.  Any otherwise  exercisable stock options will remain in
effect,  in accordance  with the terms of the stock option plan under which they
were issued,  during any period of employment with NSC and any subsequent period
during  which you may be receiving  severance  pay.  However,  in the event of a
transaction  involving  NSC which under the terms of the stock option plan would
cause the options to terminate, NSC will use its reasonable efforts to cause the
exercisability of the options to be accelerated.

      6. (a)  Termination  Without  Cause.  If you are terminated by NSC without
Cause prior to the end of the Term,  NSC will pay you (i) an amount equal to the
greater of (a) the amount of the base  salary  remaining  to be paid  during the
Term,  or (b) one year of continued  base salary  (payable in the same manner as
regular  salary),  measured  by your  base  salary in effect on the date of your
termination  and  (ii) the  Completion  Bonus  payment(s)  (as  provided  for in
paragraph  4) for the  balance of the Term.  NSC will also  provide you with one
year's  continued  coverage  under NSC's  medical  and dental  plans at the rate
applicable to active employees.  (The aforementioned  period of continued salary
and  benefits  is   hereinafter   referred  to  as  the   "Severance   Period.")
Notwithstanding  the foregoing,  your payments under this paragraph 6(a) can, at
your election, be paid in a single lump sum.

                                 Page 48 of 54
<PAGE>

      (b)  Severance.  If you are  terminated  by NSC  without  Cause  after the
expiration  of the Term of this  Agreement,  you shall be  entitled  to  receive
severance  pay for a period of six (6)  months at the rate of your  annual  base
salary  then in  effect,  payable  in the same  manner as your  regular  salary,
together with six (6) months  continued  coverage under NSC's medical and dental
plans at the rate applicable to active employees.

      (c) Cause.  For  purposes of this  Agreement,  Cause shall mean any act of
dishonesty or theft, willful misconduct, act of gross negligence, or the willful
and  continued  failure or your refusal to perform  assigned  duties (other than
caused by a  disability,  which for purposes of this  Agreement  shall mean your
total and  permanent  incapacity  to  perform  the  duties  you were  performing
immediately prior to the onset of such disability).

      7.  Survivor's  Benefit.  In the event of your death before the end of the
Term, or during the course of any applicable  Severance Period,  your spouse, if
any,  shall  receive the full (or, if your death  occurs  during any  applicable
Severance  Period,  the  remainder of the) period of  continued  base salary and
medical  and dental  coverage  set forth in  paragraph  5 above.  Further,  your
spouse,  if any, shall receive the Completion Bonus due with respect to the year
of your death under paragraph 4 above.

      8.  Affirmation.  As  further  consideration  for the  payments  and other
security set forth above,  by signing this  Agreement  you agree to abide by the
covenants and agreements set forth in Exhibit A attached hereto.

      9.  Assignment.  You may not assign your rights or obligations  hereunder.
The rights and  obligations  of NSC hereunder  shall inure to the benefit of and
shall be binding upon its respective  successors and assigns.  NSC shall use its
reasonable  efforts to ensure that any  purchaser  of the business of NSC offers
the same or substantially  equivalent plans as the medical,  dental, and vehicle
allowance plans currently offered by NSC.

      10.    General Provisions.

      (a) This  Agreement  shall be subject to and  governed  by the laws of the
Commonwealth of Massachusetts without regard to its choice of law principles.

      (b) Failure to insist upon strict compliance with any provision(s)  hereof
shall not be deemed a waiver of such provision(s) or any other provision hereof.
If all or any part of this  Agreement  is declared by any court or  governmental
authority to be unlawful or invalid,  such  unlawfulness or invalidity shall not
serve to invalidate any portion of this Agreement not declared to be unlawful or
invalid.  Any  paragraph  or a part of a paragraph so declared to be unlawful or
invalid shall,  if possible,  be construed in a manner which will give effect to
the  terms  of such  paragraph  or part of a  paragraph  to the  fullest  extent
possible while remaining lawful and valid.

      (c) This Agreement  shall not be altered,  amended,  or modified except by
written  instrument  executed  by NSC and you.  A waiver of any term,  covenant,
agreement, or condition contained in this Agreement shall not be deemed a waiver
of any other term, covenant,  agreement,  or condition any waiver of any default
in any such term, covenant, agreement, or condition shall not be deemed a waiver
of any later  default  thereof or of any other  term,  covenant,  agreement,  or
condition.

      (d) For  purposes  of this  Agreement  and each of the  Exhibits  attached
hereto,  The term "NSC" shall mean and include NSC  Corporation  and each of its
subsidiaries,  including,  but not limited to, National Surface Cleaning,  Inc.,
National Service Cleaning Corp., Olshan Demolishing Management, Inc., NSC Energy
Services, Inc. and NSC Specialty Coatings, Inc.

      (e)  NSC's  obligation  to  pay  amounts  hereunder  are  subject  to  its
withholding obligations under applicable federal, state, and local laws.

                                    NSC CORPORATION
                                    By:   ________________________

                                   ACCEPTANCE
Agreed to and accepted
this ____ day of ____________, 1996.
By:   ______________________
      Efstathios A. Kouninis

                                 Page 49 of 54

<PAGE>


                                   EXHIBIT A

      (A) I agree  that while I am  employed  by NSC,  I will not,  directly  or
indirectly, compete with the business conducted by NSC.

      (B) I agree that for a period of six (6) months after the  termination  of
employment,  whether voluntary or involuntary,  and regardless of the reason for
or  manner  of  termination,  I will  not,  alone or with  others,  directly  or
indirectly (as owner,  stockholder,  partner,  lender,  other investor director,
officer, employee, consultant or otherwise):

            (1)  Solicit,  perform  or  engage  in any  business  of the same or
similar nature to the business of NSC, or which is competitive with the business
of NSC, anywhere within the Restricted Area as hereinafter defined; and

            (2) Sell,  attempt  to sell,  provide  or  attempt  to  provide  any
products or services (in  competition  with those  products or services  which I
sold or provided on behalf of NSC) to, or solicit, perform, engage in, divert or
accept any  business of the same or similar  nature to the business of NSC from,
any person, firm or entity:

                  (a)   residing,  maintaining a principal  place of business or
                        located within the Restricted Area;

                  (b)   who was a customer  of NSC within  the  Restricted  Area
                        during   the  last   twenty-four   (24)   months  of  my
                        employment; or

                  (c)   to whom I sold, attempted to sell, provided or attempted
                        to provide  such  products or  services  during the last
                        twenty-four (24) months of my employment with NSC.

            (3) Induce or attempt to induce any  customer  of NSC to reduce such
customer's  business  with NSC or divert such  customer's  business from NSC, by
direct advertising, solicitation or otherwise.

            (4)  Disclose the names of any  customers or potential  customers of
NSC to any other person, firm, corporation or other entity.

      I agree that I will comply  with the most  restrictive  of the  provisions
specified in  subsections  (1),  (2)(a)  through (c), (3) and (4) above which is
allowed by applicable  state law. The parties agree that if  enforcement of this
Agreement is sought,  the  enforcing  court should  select the most  restrictive
provisions appropriate under applicable state law.

      (C) I agree  that while I am  employed  by NSC and for a period of six (6)
months  after  termination  of  my  employment  for  any  reason,  voluntary  or
involuntary,  with or without Cause, I will not directly or indirectly  hire, or
attempt to hire any  employee of NSC nor will I encourage or induce any employee
of NSC to terminate employment with NSC.

      (D)  "Restricted  Area"  shall mean and  include  each and every  state or
territory  in which NSC has  conducted  or  solicited  any  business  within the
twenty-four (24) months  immediately  preceding the termination of my employment
and up to and including the date of the termination of my employment. "Customer"
shall mean any  person,  firm or other  entity,  or any  parent,  subsidiary  or
affiliate  thereof,  with which NSC has had a contract,  engaged in any business
with or for which NSC has performed  any services  within the  twenty-four  (24)
months  immediately  preceding the  termination  of my employment  and up to and
including the date of the  termination  of my employment.  "Potential  Customer"
shall  mean any  person  firm or other  entity,  or any  parent,  subsidiary  or
affiliate  thereof,  from which NSC has  solicited  or  attempted to solicit any
business,  or to which NSC has  submitted  any bid or written or oral  proposal,
within the twenty-four (24) months  immediately  preceding the termination of my
employment and up to and including the date of the termination of my employment.

      I acknowledge that during the term of my employment,  I will be making use
of, acquiring,  or adding to NSC's Classified  Information.  In order to protect
the Classified  Information,  I will not,  during the term of my employment with
NSC or thereafter,  in any way utilize any of the Classified  Information except
in connection with my employment by NSC. I will not copy,  reproduce,  or remove
from NSC's premises the original or any copies of the Classified Information and
I will not disclose any of the Classified Information to anyone.

                                 Page 50 of 54

<PAGE>