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                                                                  EXHIBIT 10(tt)

                              EMPLOYMENT AGREEMENT

                  AGREEMENT dated as of the 27th day of March, 1995 by and
between ISOMEDIX INC., a Delaware corporation (the "Company"), and CHARLES P.
TRUBY (the "Employee").

                              W I T N E S S E T H :

                  WHEREAS, the Company wishes to retain the services of the
Employee, and the Employee wishes to serve in the employ of the Company, upon
the terms and conditions hereinafter set forth.

                  NOW, THEREFORE, in consideration of the premises and the
mutual agreements hereinafter set forth, the parties hereto hereby agree as
follows:

                  1. Employment, Term, Automatic Extension.

                  1.1 The Company agrees to employ the Employee, and the
Employee agrees to serve in the employ of the Company, for the term set forth in
Section 1.2, in the position and with the responsibilities, duties and authority
set forth in Section 2 and on the other terms and conditions set forth in this
Agreement.

                  1.2 The term of the Employee's employment under this Agreement
shall commence on the date hereof and shall terminate on the anniversary of the
date hereof, unless extended or sooner terminated in accordance with this
Agreement.

                  1.3 As of the expiration date of the then-current term of this
Agreement (each, an "Automatic Renewal Date"), unless either party shall have
given a notice of non-extension not less than two (2) months prior to such
Automatic Renewal Date, the term of this Agreement shall be extended
automatically for a period of one year to the anniversary of the expiration date
of the then-current term of this Agreement.

                  2. Position, Duties. The Employee shall serve in the positions
of Executive Vice President and Chief Operating Officer of the Company. The
Employee shall perform, faithfully and diligently, such duties, and shall have
such responsibilities, appropriate to said positions, as shall be assigned to
him from time to time by the Chairman of the Company or his designee and the
Board of Directors of the Company. The Employee shall report
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directly to the Chairman of the Company or his designee. The Employee shall
devote his complete and undivided attention to the performance of his duties and
responsibilities hereunder during the normal working hours of executive
employees of the Company. The Employee hereby represents that he is not bound by
any confidentiality agreements or restrictive covenants which restrict or may
restrict his ability to perform his duties hereunder, and agrees that he will
not enter into any such agreements or covenants during the term of his
employment hereunder.

                  3. Salary, Bonus.

                  3.1 During the term of this Agreement, in consideration of the
performance by the Employee of the services set forth in Section 2 and his
observance of the other covenants set forth herein, the Company shall pay the
Employee, and the Employee shall accept, a base salary at the biweekly rate of
$5,384.62, payable in accordance with the standard payroll practices of the
Company. The Employee shall be entitled to such increases in base salary during
the term hereof as shall be determined by the Board of Directors of the Company
in its sole discretion.

                  3.2 The Employee shall have a bonus opportunity with respect
to each fiscal year of the Company ending during the term of this Agreement, up
to a maximum amount of sixty percent (60%) of his base salary for such fiscal
year, in accordance with the terms of the Company's bonus program for senior
executives.

                  4. Expense Reimbursement. During the term of this Agreement,
the Company shall reimburse the Employee for all reasonable and necessary
out-of-pocket expenses incurred by him in connection with the performance of his
duties hereunder, upon the presentation of proper accounts therefor in
accordance with the Company's policies.

                  5. Benefits, Stock Options, Relocation.

                  5.1 Benefits. During the term of this Agreement, the Employee
will be eligible to participate in all employee benefit plans and programs,
including 401(K), pension, stock purchase, dental and medical plans, offered by
the Company from time to time to its employees of comparable seniority, subject
to the provisions of such plans and programs as in effect from time to time.
Commencing after one year of employment, the Employee will be entitled to two
(2) weeks' paid vacation and six (6) paid sick days per year.
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                  5.2 Stock Options. The Company shall grant to the Employee
options to purchase 50,000 shares of common stock, $.01 par value, of the
Company under the Company's 1992 Stock Option Plan at an exercise price equal to
the market value of the common stock on the date of grant. Such options shall be
subject in all respects to the terms of the Stock Option Certificate evidencing
the grant and the terms of the 1992 Stock Option Plan.

                  5.3 Relocation. The Company shall reimburse the Employee for
reasonable moving expenses incurred in his relocation from Ballwin, Missouri to
the Whippany, New Jersey area, as set forth on Schedule A to this Agreement.

                  6. Termination of Employment.

                  6.1 Death. In the event of the death of the Employee during
the term of this Agreement, the Company shall pay to the estate or other legal
representative of the Employee the base salary provided for in Section 3 (at the
biweekly rate then in effect) accrued to the date of the Employee's death and
not theretofore paid to the Employee. Rights and benefits of the estate or other
legal representative of the Employee under the benefit plans and programs of the
Company shall be determined in accordance with the provisions of such plans and
programs. Neither the estate or other legal representative of the Employee nor
the Company shall have any further rights or obligations under this Agreement.

                  6.2 Disability. If the Employee shall become incapacitated by
reason of sickness, accident or other physical or mental disability and shall be
unable to perform his duties hereunder for a period of six (6) consecutive
months or for an aggregate period of nine (9) months in any twelve (12)
consecutive months, the employment of the Employee hereunder may be terminated
by the Company or the Employee, upon thirty (30) days notice to the other party.
In the event of such termination, the Company shall pay to the Employee the base
salary provided for in Section 3 (at the biweekly rate then in effect) accrued
to the date of termination and not theretofore paid to the Employee. Rights and
benefits of the Employee under the benefit plans and programs of the Company
shall be determined in accordance with the terms and provisions of such plans
and programs. Neither the Employee nor the Company shall have any further rights
or obligations under this Agreement, except as provided in Sections 7, 8, 9 and
10.
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                  6.3 Due Cause. The employment of the Employee hereunder may be
terminated by the Company at any time for Due Cause (as hereinafter defined). In
the event of such termination, the Company shall pay to the Employee the base
salary provided for in Section 3 (at the biweekly rate then in effect) accrued
to the date of such termination and not theretofore paid to the Employee. Rights
and benefits of the Employee under the benefit plans and programs of the Company
shall be determined in accordance with the provisions of such plans and
programs. For purposes hereof, "Due Cause" shall include (a) if prior to a
Change in Control (as hereinafter defined), (i) the Employee's failure to
discharge his duties and responsibilities under this Agreement, as determined by
a majority of the Board of Directors of the Company, whose good faith
determination with respect thereto shall be conclusive and binding upon the
Employee, or (ii) the Employee's commission of (x) a felony or (y) any crime or
offense involving moral turpitude, or (b) if subsequent to a Change in Control,
(i) willful, gross neglect or willful, gross misconduct in the Employee's
discharge of his duties and responsibilties under this Agreement, or (ii) the
Employee's commission of (x) a felony or (y) any crime or offense involving
moral turpitude; provided, however, with respect to subsection (b) that the
Employee shall be given written notice by a majority of the Board of Directors
of the Company that it intends to terminate the Employee's employment for Due
Cause under subsection (b), which written notice shall specify the act or acts
upon the basis of which the majority of the Board of Directors of the Company
intends so to terminate the Employee's employment, and the Employee shall then
be given the opportunity, within fifteen (15) days of his receipt of such
notice, to have a meeting with the Board of Directors of the Company to discuss
such act or acts. If the basis of such written notice is other than an act or
acts described in subsection (b)(ii), the Employee shall be given seven (7) days
after such meeting within which to cease or correct the performance (or
nonperformance) giving rise to such written notice and, upon failure of the
Employee within such seven (7) days to cease or correct such performance (or
nonperformance), the Employee's employment by the Company shall automatically be
terminated hereunder for Due Cause. After the satisfaction of any claim of the
Company against the Employee incidental to such Due Cause, neither the Employee
nor the Company shall have any further rights or obligations under this
Agreement, except as provided in Sections 7, 8, 9 and 10.

                  6.4 Other Termination by the Company. The Company may
terminate the Employee's employment at any time for whatever reason it deems
appropriate; provided,
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however, that in the event that such termination is not pursuant to Sections
6.1, 6.2, 6.3 or 6.5, the Company shall continue to pay to the Employee, for a
period of twelve (12) months commencing on the date of termination, the base
salary provided for in Section 3.1 (at the biweekly rate then in effect). The
Company shall also pay to the Employee, within thirty (30) days of the date of
such termination, a lump sum amount in cash equal to the present value as of the
date of such termination of any unvested benefits which the Employee shall have
accrued to the date of such termination under the Isomedix Inc. Retirement Plan.
The Employee shall be under no obligation to seek subsequent employment and upon
obtaining subsequent employment shall be under no obligation to offset any
amounts earned from such subsequent employment (whether as an employee, a
consultant or otherwise) against such lump sum payments. Rights and benefits of
the Employee under the other benefit plans and programs of the Company shall be
determined in accordance with the provisions of such plans and programs. Neither
the Employee nor the Company shall have any further rights or obligations under
this Agreement, except as provided in Sections 7, 8, 9 and 10.

                  6.5 Termination of Employment Following a Change in Control.
The Employee may terminate his employment with the Company during the one (1)
year period following a Change in Control. In the event of such termination or a
termination by the Company during such one (1) year period other than for Due
Cause, the Company shall pay to the Employee, within thirty (30) days of the
date of such termination, (i) a lump sum amount in cash equal to two times his
annual base salary (at the biweekly rate then in effect), and (ii) a lump sum
amount in cash equal to the present value as of the date of such termination of
any unvested benefits which the Employee shall have accrued to the date of such
termination under the Isomedix Inc. Retirement Plan. The Employee shall be under
no obligation to seek subsequent employment and upon obtaining subsequent
employment shall be under no obligation to offset any amounts earned from such
subsequent employment (whether as an employee, a consultant or otherwise)
against such lump sum payments. For purposes of this Agreement, a Change in
Control of the Company shall be deemed to have occurred if:

                           (A) a "person" (meaning an individual, a partnership,
or other group or association as defined in Sections 13(d) and 14(d) of the
Securities Exchange Act of 1934, other than the Employee or a group including
the Employee), acquires twenty percent (20%) or more of the combined voting
power of the outstanding securities of the Company having a right to vote in
elections of directors
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and such acquisition shall not have been approved within sixty (60) days
following such acquisition by a majority of the Continuing Directors (as
hereinafter defined) then in office; or

                           (B) Continuing Directors shall for any reason cease
to constitute a majority of the Board of Directors of the Company; or

                           (C) the business of the Company is disposed of by the
Company to a party or parties other than a subsidiary or other affiliate of the
Company, in which the Company owns less than a majority of the equity, pursuant
to a partial or complete liquidation of the Company, sale of assets (including
stock of a subsidiary of the Company) or otherwise, and such disposition shall
not have been approved in advance by a majority of the Continuing Directors then
in office.

                  For purposes of this Agreement, the term "Continuing Director"
shall mean a member of the Board of Directors of the Company who either was a
member of the Board of Directors on the date hereof or who subsequently became a
Director and whose election, or nomination for election, was approved by a vote
of at least two-thirds of the Continuing Directors then in office.

                  7.       Confidential Information.

                  7.1 The Employee shall, during the Employee's employment with
the Company and thereafter, treat all confidential material confidentially and,
except in accordance with the terms of this Agreement, shall not, without the
prior written consent of a majority of the Board of Directors of the Company,
disclose such material, directly or indirectly, to any party not at the time of
such disclosure an employee or agent of the Company, or remove from the
Company's premises any notes or records relating thereto, copies or facsimiles
thereof (whether made by electronic, electrical, magnetic, optical, laser,
acoustic or other means), or any other property of the Company. The Employee
agrees that all confidential material, together with all notes and records of
the Employee relating thereto, and all copies or facsimiles thereof in the
possession of the Employee (whether made by the foregoing or other means) are
the exclusive property of the Company. The Employee shall not in any manner use
any confidential material, or any other property of the Company, in any manner
not specifically directed by the Company or in any way which is detrimental to
the Company,
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as determined by a majority of the Board of Directors of the Company in its sole
discretion.

                  7.2 For the purposes hereof, the term "confidential material"
shall mean all information in any way concerning the activities, business or
affairs of the Company or the Company's customers and clients, including,
without limitation, information concerning trade secrets and the preparation of
raw material for, manufacture of, and/or finishing processes utilized in the
production of, the products or projects of the Company and/or any improvements
therein, together with all sales and financial information concerning the
Company and any and all information concerning projects in research and
development or marketing plans for any such products or projects, and all
information concerning the practices, customers and clients of the Company, and
all information in any way concerning the activities, business or affairs of any
of such customers or clients, as such, which is furnished to the Employee by the
Company or any of its agents, customers or clients, as such, or otherwise
acquired by the Employee in the course of the Employee's employment with the
Company; provided, however, that the term "confidential material" shall not
include information which (i) becomes generally available to the public other
than as a result of a disclosure by the Employee, (ii) was available to the
Employee on a non-confidential basis prior to his employment with the Company or
(iii) becomes available to the Employee on a non-confidential basis from a
source other than the Company or any of its agents, customers or clients, as
such, provided that such source is not bound by a confidentiality agreement with
the Company or any of such agents, customers or clients.

                  7.3 Promptly upon the request of the Company, the Employee
shall deliver to the Company all confidential material in the possession of the
Employee without retaining a copy thereof, unless, in the opinion of counsel for
the Company, either returning such confidential material or failing to retain a
copy thereof would violate any applicable Federal, state, local or foreign law,
in which event such confidential material shall be returned without retaining
any copies thereof as soon as practicable after such counsel advises that the
same may be lawfully done.

                  7.4 In the event that the Employee is required, by oral
questions, interrogatories, requests for information or documents, subpoena,
civil investigative demand or similar process, to disclose any confidential
material, the Employee shall provide the Company with
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prompt notice thereof so that the Company may seek an appropriate protective
order and/or waive compliance by the Employee with the provisions hereof;
provided, however, that if in the absence of a protective order or the receipt
of such a waiver, the Employee is, in the opinion of counsel for the Company,
compelled to disclose confidential material not otherwise disclosable hereunder
to any legislative, judicial or regulatory body, agency or authority, or else be
exposed to liability for contempt, fine or penalty or to other censure, such
confidential material may be so disclosed.

                  8. Intellectual Property. Any and all inventions made,
developed or created by the Employee (whether at the request or suggestion of
the Company or otherwise, whether alone or in conjunction with others, and
whether during regular hours of work or otherwise) (a) during the period of this
Agreement, or (b) within a period of one (1) year after the date of termination
of employment hereunder, which may be directly or indirectly useful in, or
relate to, the business of or tests being carried out by the Company, shall be
promptly and fully disclosed by the Employee to the Board of Directors of the
Company and shall be the Company's exclusive property as against the Employee,
and the Employee shall promptly deliver to an appropriate representative of the
Company as designated by the Board of Directors all papers, drawings, models,
data and other material relating to any invention made, developed or created by
him as aforesaid. The Employee shall, at the request of the Company and without
any payment therefor, execute any documents necessary or advisable in the
opinion of the Company's counsel to direct issuance of patents or copyrights to
the Company with respect to such inventions as are to be the Company's exclusive
property as against the Employee or to vest in the Company title to such
inventions as against the Employee. The expense of securing any such patent or
copyright shall be borne by the Company.

                  9. Interference with the Company. The Employee acknowledges
that the services to be rendered by him to the Company are of a special and
unique character. The Employee agrees that, in consideration of his employment
hereunder, the Employee will not (a) during the period of his employment with
the Company and thereafter for a period of one year commencing on the date of
termination of his employment with the Company (i) solicit or entice or endeavor
to solicit or entice away from the Company any person who was an officer,
employee or consultant of the Company, either on his own account or for any
person, firm, corporation or other organization,
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whether or not such person would commit any breach of his contract of employment
by reason of leaving the service of the Company, and the Employee agrees not to
employ, directly or indirectly, any person who was an officer or employee of the
Company or who by reason of such position at any time is or may be likely to be
in possession of any confidential information or trade secrets relating to the
businesses or products of the Company or (ii) solicit or entice or endeavor to
solicit or entice away from the Company any present or prospective customer of
the Company, or (b) at any time, take any action or make any statement the
effect of which would be, directly or indirectly, to impair the good will of the
Company or the business reputation or good name of the Company, or be otherwise
detrimental to the interests of the Company, including any action or statement
intended, directly or indirectly, to benefit a competitor of the Company. For
purposes hereof, "prospective customer" shall refer to a customer with whom the
Company has had significiant contact regarding the provision of products or
services to such customer during the three (3) month period preceding the
termination of the Employee's employment hereunder.

                  10. Equitable Relief. In the event of a breach or threatened
breach by the Employee of any of the provisions of Sections 7, 8 or 9 of this
Agreement, the Employee hereby consents and agrees that the Company shall be
entitled to an injunction or similar equitable relief from any court of
competent jurisdiction restraining the Employee from committing or continuing
any such breach or threatened breach or granting specific performance of any act
required to be performed by the Employee under any of such provisions, without
the necessity of showing any actual damage or that money damages would not
afford an adequate remedy and without the necessity of posting any bond or other
security. Nothing herein shall be construed as prohibiting the Company from
pursuing any other remedies at law or in equity which it may have.

                  11. Successors and Assigns.

                  11.1 Assignment by the Company. The Company shall require any
successors (whether direct or indirect, by purchase, merger, consolidation or
otherwise) to all or substantially all of the business and/or assets of the
Company to assume and agree to perform this Agreement in the same manner and to
the same extent that the Company would be required to perform if no such
succession had taken place. As used in this Section, the "Company" shall mean
the Company as hereinbefore defined and any successor to its business and/or
assets as aforesaid which otherwise
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becomes bound by all the terms and provisions of this Agreement by operation of
law and this Agreement shall be binding upon, and inure to the benefit of, the
Company, as so defined.

                  11.2 Assignment by the Employee. The Employee may not assign
this Agreement or any part thereof without the prior written consent of a
majority of the Board of Directors of the Company; provided, however, that
nothing herein shall preclude one or more beneficiaries of the Employee from
receiving any amount that may be payable following the occurrence of his legal
incompetency or his death and shall not preclude the legal representative of his
estate from receiving such amount or from assigning any right hereunder to the
person or persons entitled thereto under his will or, in the case of intestacy,
to the person or persons entitled thereto under the laws of intestacy applicable
to his estate. The term "beneficiaries", as used in this Agreement, shall mean a
beneficiary or beneficiaries so designated to receive any such amount or, if no
beneficiary has been so designated, the legal representative of the Employee (in
the event of his incompetency) or the Employee's estate.

                  12. Governing Law. This Agreement shall be deemed a contract
made under, and for all purposes shall be construed in accordance with, the laws
of the State of New Jersey applicable to contracts to be performed entirely
within such State. In the event that a court of any jurisdiction shall hold any
of the provisions of this Agreement to be wholly or partially unenforceable for
any reason, such determination shall not bar or in any way affect the Company's
right to relief as provided for herein in the courts of any other jurisdiction.
Such provisions, as they relate to each jurisdiction, are, for this purpose,
severable into diverse and independent covenants. Service of process on the
parties hereto at the addresses set forth herein shall be deemed adequate
service of such process.

                  13. Entire Agreement. This Agreement contains all the
understandings and representations between the parties hereto pertaining to the
subject matter hereof and supersedes all undertakings and agreements, whether
oral or in writing, if any there be, previously entered into by them with
respect thereto.

                  14. Amendment, Modification, Waiver. No provision of this
Agreement may be amended or modified unless such amendment or modification is
agreed to in writing and signed by the Employee and by a duly authorized
representative of the Company other than the Employee.
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Except as otherwise specifically provided in this Agreement, no waiver by either
party hereto of any breach by the other party hereto of any condition or
provision of this Agreement to be performed by such other party shall be deemed
a waiver of a similar or dissimilar provision or condition at the same or any
prior or subsequent time, nor shall the failure of or delay by either party
hereto in exercising any right, power or privilege hereunder operate as a waiver
thereof to preclude any other or further exercise thereof or the exercise of any
other such right, power or privilege.

                  15. Arbitration. Any controversy or claim arising out of or
relating to this Agreement, or any breach thereof, shall, except as provided in
Section 10, be settled by arbitration in accordance with the rules of the
American Arbitration Association then in effect and judgment upon such award
rendered by the arbitrator may be entered in any court having jurisdiction
thereof. The arbitration shall be held in the area where the Company then has
its principal place of business. The arbitration award shall include attorneys'
fees and costs to the prevailing party.

                  16. Notices. Any notice to be given hereunder shall be in
writing and delivered personally or sent by certified mail, postage prepaid,
return receipt requested, addressed to the party concerned at the address
indicated below or at such other address as such party may subsequently
designate by like notice:

                  If to the Company:

                           Isomedix Inc.
                           11 Apollo Drive
                           Whippany, New Jersey  07981
                           Attention:  Mr. John Masefield

                  If to the Employee:

                           Charles P. Truby
                           1976 Woodmoor Ridge Drive
                           Ballwin, Missouri  63011

                  17. Severability. Should any provision of this Agreement be
held by a court or arbitration panel of competent jurisdiction to be enforceable
only if modified, such holding shall not affect the validity of the remainder of
this Agreement, the balance of which shall continue to be binding upon the
parties hereto with any such modification to become a part hereof and treated as
though
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originally set forth in this Agreement. The parties further agree that any such
court or arbitration panel is expressly authorized to modify any such
unenforceable provision of this Agreement in lieu of severing such unenforceable
provision from this Agreement in its entirety, whether by rewriting the
offending provision, deleting any or all of the offending provision, adding
additional language to this Agreement, or by making such other modifications as
it deems warranted to carry out the intent and agreement of the parties as
embodied herein to the maximum extent permitted by law. The parties expressly
agree that this Agreement as so modified by the court or arbitration panel shall
be binding upon and enforceable against each of them. In any event, should one
or more of the provisions of this Agreement be held to be invalid, illegal or
unenforceable in any respect, such invalidity, illegality or unenforceability
shall not affect any other provisions hereof, and if such provision or
provisions are not modified as provided above, this Agreement shall be construed
as if such invalid, illegal or unenforceable provisions had never been set forth
herein.

                  18. Withholding. Anything to the contrary notwithstanding, all
payments required to be made by the Company hereunder to the Employee or his
beneficiaries, including his estate, shall be subject to withholding of such
amounts relating to taxes as the Company may reasonably determine it should
withhold pursuant to any applicable law or regulation. In lieu of withholding
such amounts, in whole or in part, the Company, may, in its sole discretion,
accept other provision for payment of taxes as permitted by law, provided it is
satisfied in its sole discretion that all requirements of law affecting its
responsibilities to withhold such taxes have been satisfied.

                  19. Survivorship. The respective rights and obligations of the
parties hereunder shall survive any termination of this Agreement to the extent
necessary to the intended preservation of such rights and obligations.

                  20. Titles. Titles of the sections of this Agreement are
intended solely for convenience and no provision of this Agreement is to be
construed by reference to the title of any section.
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                  IN WITNESS WHEREOF, the parties hereto have executed this
Agreement as of the date first above written.

                                                   ISOMEDIX INC.



                                                   By/s/ John Masefield
                                                     --------------------------


                                                    /s/ Charles P. Truby
                                                    ---------------------------
                                                        Charles P. Truby
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                                   SCHEDULE A


a.      Normal moving expense to the new location for:

                -        Packing and unpacking
                -        Shipping
                -        Insurance on household goods and personal
                         effects
                -        En route expenses (transportation, meals,
                         lodging, laundry)
                -        Automobile moving or mileage allowance for
                         second vehicle
                -        Storage expenses for household goods and
                         personal effects for as many as 30 days
                -        Normal hook up of utilities at the new
                         location

b.      Reimbursement of points for the residence purchased in New Jersey.

c.      Living expenses for up to 90 days in the vicinity of Whippany, 
        New Jersey, if temporary housing is required.

d.      Vehicle rental for up to 90 days prior to permanent move.

e.      Required personal travel back to St. Louis upon my approval by the 
        President of the Company.

f.      Normal brokerage commissions applicable to the sale of your present 
        residence.