<PAGE>

                                 EXHIBIT 10.11

                             EMPLOYMENT AGREEMENT


         This EMPLOYMENT AGREEMENT (the "Agreement") entered into as of the 20th
day of August 2001, between SFBC Analytical Laboratories, Inc., a Florida
corporation (the "Company") and Dr. Allan Xu (the "Employee").

         WHEREAS, in its business, the Company has acquired and developed
certain trade secrets, including but not limited to proprietary processes, sales
methods and techniques, and other like confidential business and technical
information including but not limited to technical information, design systems,
methods of recruiting subjects, pricing methods, pricing rates or discounts,
process, procedure, formula, design of computer software or improvement of any
portion or phase thereof, whether patented or not, that is of any value
whatsoever to the Company, as well as certain unpatented information relating to
the Company's Services, as defined, information concerning proposed new
Services, market feasibility studies, proposed or existing marketing techniques
or plans (whether developed or produced by the Company or by any other entity
for the Company), other Confidential Information, as defined by Section 8, and
information about the Company's employees, officers, and directors, which
necessarily will be communicated to the Employee by reason of his employment by
the Company; and

         WHEREAS, the Company has on the date hereof purchased all of the
capital stock of KeyStone Analytical Laboratories, Inc., a Pennsylvania
corporation ("KAL"); and

         WHEREAS, the Employee was President and Chief Executive Officer of KAL
and has served in that capacity for several years; and

         WHEREAS, the Company desires to continue to employ the Employee in the
capacity of President of the Company and the Employee desires such employment;
and

         WHEREAS, the Company has strong and legitimate business interests in
preserving and protecting its investment in the Employee, its trade secrets and
Confidential Information, and its substantial relationships with suppliers, and
Customers, as defined, actual and prospective; and

         WHEREAS, the Company desires to preserve and protect its legitimate
business interests further by restricting competitive activities of the Employee
during the term of employment and following (for a reasonable time) termination
of employment; and

         WHEREAS, the Company desires to employ the Employee and to ensure the
continued availability to the Company of the Employee's services, and the
Employee is willing to accept such employment and render such services, all upon
and subject to the terms and conditions contained in this Agreement;

         NOW, THEREFORE, in consideration of the premises and the mutual
covenants set forth in this Agreement, and intending to be legally bound, the
Company and the Employee agree as follows:

                                       1
<PAGE>

         1.    Representations and Warranties. The Employee hereby represents
               ------------------------------
and warrants to the Company that he (i) is not subject to any written
nonsolicitation or noncompetition agreement affecting his employment with the
Company (other than any prior agreement with the Company or any Affiliate), (ii)
is not subject to any written confidentiality or nonuse/nondisclosure agreement
affecting his employment with the Company (other than any prior agreement with
the Company or any Affiliate), and (iii) has brought to the Company no trade
secrets, confidential business information, documents, or other personal
property of a prior employer.


         2.    Term of Employment.
               ------------------

               (a)    Term. The Company hereby employs the Employee, and the
                      ----
Employee hereby accepts employment with the Company for a period commencing on
the date of this Agreement and ending five years from the date of this Agreement
(the "Term"), automatically renewable for additional one year terms unless
either party gives the other at least 30 days written notice.

               (b)    Continuing Effect. Notwithstanding any termination of
                      -----------------
employment, at the end of the term or otherwise, the provisions of Sections 7
and 8 shall remain in full force and effect and the provisions of Section 8
shall be binding upon the legal representatives, successors and assigns of the
Employee.

         3.    Duties.
               ------

               (a)    General Duties. The Employee shall serve as President of
                      --------------
the Company, with duties and responsibilities that are customary for such
position. Subject to the authority of the board of directors of the Company to
set policy and ensure that the business is effectively managed and operated, the
Employee shall be principally responsible for the management of the business of
the Company, including, but not limited to (i) preparing and implementing an
operating budget in coordination with the Company's sales and marketing team;
(ii) planning and budgeting for the Company so services can be provided on a
timely basis; (iii) planning and budgeting for the organization and development
of the Company's business; (iv) research and development activities relating to
new services of the Company and improvements to the Company' existing services;
(v) all technical, operational, and other aspects of the Company's services;
(vi) all distribution, marketing, and sales activities relating to the Company's
services; and (vii) compliance with all applicable requirements of any
applicable federal, state, or local government agency or entity and any
applicable law or regulation concerning the Company's services, facilities and
business. The Employee shall report directly to the Company's board of directors
and any person designated by the board, which shall initially be Dr. Gregory B.
Holmes. The Employee shall use his best efforts to perform his duties and
discharge his responsibilities pursuant to this Agreement competently, carefully
and faithfully. The Employee shall also serve as a director of the Company and
of each of the Company's subsidiaries, if any.

               (b)    Devotion of Time. The Employee shall devote all of his
                      ----------------
time, attention and energies during normal business hours (exclusive of periods
of sickness and disability and of such normal holiday and vacation periods as
have been established by the Company) to the affairs of the

                                       2
<PAGE>

Company. The Employee shall not without the prior written consent of the board
of directors of the Company, enter the employ of or serve as a consultant to, or
in any way perform any services with or without compensation to, any other
persons, business or organization or engage in any other business activities or
pursuits whatsoever, except activities in connection with any charitable or
civic activities, personal investments or hobbies and serving as an executor,
trustee or in other similar fiduciary capacity; provided, however, that such
                                                --------  -------
activities do not interfere with his performance of his responsibilities and
obligations pursuant to this Agreement.

               (c)    Location of Office. The Employee's principal business
                      ------------------
office shall be at the Company's offices in North Wales, Pennsylvania, as it may
change from time to time. However, the Employee's job responsibilities shall
include reasonable business travel necessary to the performance of his job. In
any event, the Employee's services shall be supervised by Dr. Gregory B. Holmes
or other designated member of the Company's board of directors located in Miami,
Florida. As such, the Employee shall regularly transact business with or in
Miami-Dade County, Florida in furtherance of his duties.

               (d)    Adherence to Inside Information Policies. The Employee
                      ----------------------------------------
acknowledges that the Company's parent, SFBC International, Inc. (the "Parent")
is publicly-held and, as a result, has implemented inside information policies
designed to preclude its employees and those of its subsidiaries from violating
the federal securities laws by trading on material, non-public information or
passing such information on to others in breach of any duty owed to the Parent,
the Company, or any third party. The Employee shall promptly execute any
agreements generally distributed by the Parent or the Company to its employees
requiring such employees to abide by its inside information policies.


          4.   Compensation and Expenses.
               -------------------------

               (a)    Salary. For the services of the Employee to be rendered
                      ------
under this Agreement, the Company shall pay the Employee an annual salary of
$170,000 during the Term, payable in accordance with the Company's normal
payroll practices.

               (b)    Expenses. In addition to any compensation received
                      --------
pursuant to Section 4(a) the Company shall reimburse or advance funds to the
Employee for all reasonable travel, entertainment and miscellaneous expenses
incurred in connection with the performance of his duties under this Agreement
provided the same are of a type which are allowable for deductions under
applicable federal law, and (ii) provided that the Employee properly provides a
written accounting of such expenses to the Company in accordance with the
Company's practices. Such reimbursement or advances shall be made in accordance
with policies and procedures of the Company in effect from time to time relating
to reimbursement of or advances to Employees.


               (c)    Automobile.  The Company shall pay the Employee a monthly
                      ----------
automobile allowance of $650 per month.

                                       3
<PAGE>

               (d)    Discretionary Bonus. The Employee shall be eligible to
                      --------------------
receive an annual bonus in an amount to be determined by the compensation
committee of the Company based on any criteria or factors the compensation
committee deems appropriate.

               (e)    Special Bonus. As collected, the Company shall pay the
                      -------------
Employee a special bonus equal to (i) 50% of KAL's unbilled accounts receivable
as of June 30, 2001 (estimated to be $980,000), (ii) less any undisclosed
liabilities of KAL which have been paid by the Company or have been asserted and
for which the Company has potential liability provided that in no event shall
the total liability exceed that set forth in the Indemnification Agreement by
and among SFBC International, Inc., the Company and the Employee dated August
20, 2001. In the event that the Employee fails to pay the Company for an
undisclosed liability under the above circumstances, he shall borrow a
sufficient sum in a margin account using shares of the Company's common stock as
collateral as soon as he may do so, subject to compliance with all applicable
securities laws and any lock-up agreement with the Company.

               (f)    Loan. In order to induce the Employee to enter into this
                      ----
Agreement the Company has lent him the sum of $1,000,000, for which he
acknowledges receipt, as evidenced by the Promissory Note and secured by a
pledge (the "Pledge Agreement") of the Parent's common stock, each as annexed as
Exhibit 4(f)-1 and Exhibit 4(f)-2 to this Agreement and each of which has been
--------------     --------------
executed and delivered to the Company. If the Employee is still employed by the
Company on an anniversary date of this Agreement (the "Anniversary Date")
through the fifth Anniversary Date: (i) the sum of $200,000 together with
applicable interest shall be forgiven and considered paid by the Employee to the
Company on each applicable Anniversary Date; and (ii) a pro rata portion of the
Parent's common stock shall be released subject to the terms of the Pledge
Agreement.


          5.   Benefits.  The Employee is entitled to the following benefits.
               --------

               (a)    Vacation. The Employee shall be entitled to up to four (4)
                      --------
weeks of vacation without loss of compensation or other benefits to which he is
entitled under this Agreement, to be taken at such times as the Employee may
select and the affairs of the Company may permit.

               (b)    Employee Benefit Programs. The Employee is entitled to
                      -------------------------
participate in any pension, 401(k), insurance or other employee benefit plan
that is maintained by the Company for its non-executive officer employees,
including programs of life and medical insurance and reimbursement of membership
fees in professional organizations.

               (c)   Insurance. The Company shall pay the premiums on the
                     ---------
Company's medical insurance policy covering the Employee and his spouse. The
Company shall pay the premiums for disability insurance covering the Employee's
disability which insurance shall, subject to state law variances or
requirements, be similar in scope including waiting time and percentage of
disability income to the disability insurance provided to employee's of SFBC
Charlotte, Inc., a subsidiary of the Parent.

               (d)    Key Man Insurance. The Company shall maintain a key man
                      -----------------
insurance policy on the life of the Employee in the original principal amount of
$1,000,000 or at the

                                       4
<PAGE>

Company's option, in an amount not less than the then outstanding principal
balance of the Promissory Note and shall name the Company as beneficiary under
such policy.


          6.   Termination.
               -----------

               (a)    General Provisions. The Company may terminate the
                      ------------------
Employee's employment for Cause (as defined below) pursuant to the terms of this
Agreement at any time upon the giving of notice. On or before the termination of
his employment or prior to receiving any final compensation or expenses due him,
the Employee shall (i) return to the Company's principal executive offices, (ii)
participate in an exit interview, and (iii) execute a Certificate of Conclusion
of Employment, certifying that he has complied with his obligations and
acknowledging his continuing obligations under this Agreement. The Employee's
failure to comply with the requirements of Section 6 of this Agreement shall
constitute a material breach of this Agreement.

               (b)    Termination for Cause. The Company may terminate the
                      ---------------------
Employee's employment pursuant to the terms of this Agreement at any time for
Cause by giving written notice of termination. The Employee shall have 10 days
from the date of the notice to provide the Company with evidence that the
Company is mistaken as to "Cause" and that the Employee's behavior does not meet
the criteria for "cause" as defined herein. During such 10 day period the
Employee shall be suspended without pay; if employment is reinstated the
Employee shall be paid for the 10 day period and if the termination is upheld
such termination shall be effective upon the giving of written notice of
termination. Upon any such termination for Cause, the Employee shall have no
right to compensation or reimbursement under Section 4, or to participate in any
employee benefit programs under Section 5, except as provided by law, for any
period subsequent to the effective date of termination. For purposes of this
Section 6(b), "Cause" shall mean: (i) the Employee is convicted of a felony
involving any subject matter; (ii) commits a felonious act; (iii) is convicted
of a misdemeanor involving the Employee's employment or the business of the
Company; (iv) is found after an internal investigation to have engaged in sexual
misconduct which is related to the Employee's employment or the business of the
Company; (v) the Employee, in carrying out his duties hereunder, has acted with
gross negligence or intentional misconduct resulting, in either case, in harm to
the Company; (vi) the Employee misappropriates Company funds or otherwise
defrauds the Company; (vii) the Employee breaches his fiduciary duty to the
Company resulting in profit to him, directly or indirectly; (viii) the Employee
has been found to have committed any act or failed to take any action which
results in the Parent's common stock being delisted for trading on the Nasdaq
Stock Market or any other principal trading market or exchange; (ix) substantial
dependence on any addictive substance, including but not limited to, alcohol,
amphetamines, barbiturates, methadone, cannabis, cocaine, CP, THC, LSD or any
other illegal or narcotic drug; (x) willful and material failure to observe or
perform his duties of employment hereunder; (xi) the Employee misappropriates
Company funds or otherwise defrauds the Company; (xii) the Employee willfully
acts in a manner materially adverse to the best interests of the Company; (xiii)
the habitual neglect of the faithful performance of the Employee's duties of
employment, as determined in good faith by the board of directors of the
Company; (xiv) the Employee is convicted of illegal possession or use of a
controlled substance; (xv) the Employee engages in chronic absenteeism; (xvi)
the Employee fails or refuses to cooperate in any official

                                       5
<PAGE>

investigation conducted by or on behalf of the Company; or (xvii) the Employee
materially breaches any provision of this Agreement including Section 3(d).

               (e)    Voluntary Severance Payments Upon Termination. If the
                      ---------------------------------------------
Employee is terminated for cause pursuant to Section 6(b), or if the Employee
voluntarily terminates his employment, the Company may elect in its sole
discretion, notwithstanding the basis for such termination, to make monthly
severance payments to the Employee in amounts equal to his then existing monthly
base salary prior to such termination and may further elect to continue only the
Employee's medical benefits, as they existed prior to termination. The
Employee's compliance after termination to his obligations under Sections 7 and
8 hereunder shall be a condition precedent to the making of any discretionary
payment under this Section 6(c).

               (f)    Special Termination. In the event that (i) any entity or
                      -------------------
person not now an executive officer or director of the Company becomes either
individually or as part of a group, the beneficial owner of 30% or more of the
Company's common stock, and (ii) the Employee, with or without change in title
or formal corporate action, shall no longer exercise all of the duties and
responsibilities and shall no longer possess substantially all the authority set
forth in Section 3, the Employee by written notice to the Company, may elect to
deem the Employee's employment hereunder to have been terminated by the Company
without cause, in which event the Employee shall be entitled at the time of
termination to compensation in an amount equal to 24 months base salary under
this Agreement plus benefits pursuant to Section 5(b) herein for such 24 month
period payable, however, on a monthly basis.


          7.   Non-Competition Agreement.
               -------------------------

               (a)    Competition with the Company. Until termination of his
                      ----------------------------
employment and for a period of 24 months commencing on the date of Employees
termination, the Employee, directly or indirectly or, in association with or as
a stockholder, director, officer, consultant, employee, partner, joint venturer,
member or otherwise of or through any person, firm, corporation, partnership,
association or other entity (any of the foregoing defined as an "Affiliated
Entity") shall not provide services as an employee, consultant or otherwise (i)
to any entity or person if the Company elects to make payments to the Employee
under Section 6(e) hereof, or (ii) in the absence of such election, to any
analytical laboratory or to any entity which directly or indirectly owns or
operates an analytical laboratory or to any entity that competes with the
Company or its Affiliates, within any metropolitan area in the United States or
elsewhere in which the Company's, its subsidiaries or its controlling
stockholder, if applicable (the subsidiaries and controlling stockholder
collectively, "Affiliates") is then engaged in the offer and sale of competitive
products or Services (defined in Section 8(a) below). In addition, the Employee
may not, directly or indirectly including through any Affiliated Entity, obtain
employment with or perform services for any Customer, as defined, of the Company
or any Affiliate during the period commencing of the date of termination and
continuing for 24 months thereafter; provided, however, the foregoing shall not
                                     --------  -------
prohibit Employee from owning up to 5% of the securities of any publicly-traded
enterprise provided the Employee is not an employee, director, officer,
consultant to such enterprise or otherwise reimbursed for services rendered to
such enterprise.

                                       6
<PAGE>

                (b)    Solicitation of Customers. During the periods in which
                       -------------------------
the provisions of Section 7(a) shall be in effect, the Employee, directly or
indirectly including through any Affiliated Entity, shall not seek Prohibited
Business from any Customer (as defined below) on behalf of any enterprise or
business other than the Company or any Affiliate, refer Prohibited Business from
any Customer to any enterprise or business other than the Company or any
Affiliate or receive commissions based on sales or otherwise relating to the
Prohibited Business from any Customer, or any enterprise or business other than
the Company or any Affiliate. For purposes of this Agreement, the term
"Customer" means any person, firm, corporation, partnership, association or
other entity to which the Company or any of its Affiliates sold or provided
goods or services during the 24-month period prior to the time at which any
determination is required to be made as to whether any such person, firm,
corporation, partnership, association or other entity is a Customer, or who or
which has approached by or who or which has approached an employee of the
Company or any Affiliate for the purpose of soliciting business from the Company
or any Affiliate or the third party, as the case may be.

                (c)    Solicitation of Employees. During the periods in which
                       -------------------------
the provisions of Section 7(a) shall be in effect, the Employee, directly or
indirectly including through any Affiliated Entity shall not solicit, hire or
contact any employee of the Company or any Affiliate for the purpose of hiring
them or causing them to terminate their employment relationship with the Company
or any Affiliate.

                (d)    No Payment. The Employee acknowledges and agrees that no
                       ----------
separate or additional payment will be required to be made to him in
consideration of his undertakings in this Section.

                (e)    References to the Company in this Section 7 shall include
the Company's Affiliates including the Parent.


          8.    Non-Disclosure of Confidential Information.
                ------------------------------------------

                (a)    Confidential Information. Confidential Information
                       ------------------------
includes, but is not limited to, trade secrets as defined by the common law and
statute in Florida or any future Florida statute, processes, policies,
procedures, techniques, designs, drawings, know-how, show-how, technical
information, specifications, computer software and source code, information and
data relating to the development, research, testing, costs, marketing and uses
of the Services (as defined herein), the Company's budgets and strategic plans,
and the identity and special needs of Customers, databases, data, all technology
relating to the Company's businesses, systems, methods of operation, client or
Customer lists, Customer information, solicitation leads, marketing and
advertising materials, methods and manuals and forms, all of which pertain to
the activities or operations of the Company, names, home addresses and all
telephone numbers and e-mail addresses of the Company's employees, former
employees, clients and former clients. In addition, Confidential Information
also includes the identity of Customers and the identity of and telephone
numbers, e-mail addresses and other addresses of employees or agents of
Customers who are the persons with whom the Company's employees and agents
communicate in the ordinary course of business. Confidential Information also
includes, without limitation, Confidential Information received from the
Company's Affiliates. For purposes of this Agreement, the following will not
constitute Confidential Information (i) information which is or subsequently
becomes generally

                                       7
<PAGE>

available to the individuals employed within the Company's industry through no
act of the Employee, (ii) information set forth in the written records of the
Employee prior to disclosure to the Employee by or on behalf of the Company
which information is given to the Company in writing as of or prior to the date
of this Agreement, and (iii) information which is lawfully obtained by the
Employee in writing from a third party (excluding any Affiliates (which includes
the Parent) of the Employee) who did not acquire such confidential information
or trade secret, directly or indirectly, from the Employee or the Company. As
used herein, the term "Services" shall include the operation of an analytical
laboratory which provide services to pharmaceutical, biotechnology and chemical
companies and contract research organizations as well as any other services
performed by the Company during the term of the Employee's employment.

               (b)    Legitimate Business Interests. The Employee recognizes
                      -----------------------------
that the Company has legitimate business interests to protect and as a
consequence, the Employee agrees to the restrictions contained in this Agreement
because they further the Company's legitimate business interests. These
legitimate business interests include, but are not limited to (i) trade secrets;
(ii) valuable confidential business or professional information that otherwise
does not qualify as trade secrets including all Confidential Information; (iii)
substantial relationships with specific prospective or existing Customers or
clients; (iv) customer or client goodwill associated with the Company's
business; and (v) specialized training relating to the Company's technology,
methods and procedures.

               (c)    Confidentiality. For a period of two years following
                      ---------------
termination of employment, or as otherwise required by client privilege, the
Confidential Information shall be held by the Employee in the strictest
confidence and shall not, without the prior written consent of the Company, be
disclosed to any person other than in connection with the Employee's employment
by the Company. The Employee further acknowledges that such Confidential
Information as is acquired and used by the Company or its Affiliates is a
special, valuable and unique asset. The Employee shall exercise all due and
diligence precautions to protect the integrity of the Company's Confidential
Information and to keep it confidential whether it is in written form, on
electronic media or oral. The Employee shall not copy any Confidential
Information except to the extent necessary to his employment nor remove any
Confidential Information or copies thereof from the Company's premises except to
the extent necessary to his employment and then only with the authorization of
an officer of the Company. All records, files, materials and other Confidential
Information obtained by the Employee in the course of his employment with the
Company are confidential and proprietary and shall remain the exclusive property
of the Company or its customers, as the case may be. The Employee shall not,
except in connection with and as required by his performance of his duties under
this Agreement, for any reason use for his own benefit or the benefit of any
person or entity with which he may be associated or disclose any such
Confidential Information to any person, firm, corporation, association or other
entity for any reason or purpose whatsoever without the prior written consent of
an officer of the Company (excluding the Employee, if applicable).

               (d)    References to the Company in this Section 8 shall include
the Company's Affiliates.

                                       8
<PAGE>

          9.   Equitable Relief.
               ----------------

               (a)    The Company and the Employee recognize that the services
to be rendered under this Agreement by the Employee are special, unique and of
extraordinary character, and that in the event of the breach by the Employee of
the terms and conditions of this Agreement or if the Employee, shall cease to be
an employee of the Company for any reason and take any action in violation of
Section 7 and/or Section 8, the Company shall be entitled to institute and
prosecute proceedings in any court of competent jurisdiction referred to in
Section 9(b) below, to enjoin the Employee from breaching the provisions of
Section 7 or Section 8. In such action, the Company shall not be required to
plead or prove irreparable harm or lack of an adequate remedy at law or post a
bond or any security.

               (b)    Any action must be commenced in Miami-Dade County,
Florida. The Employee and the Company irrevocably and unconditionally submit to
the exclusive jurisdiction of such courts and agree to take any and all future
action necessary to submit to the jurisdiction of such courts. The Employee and
the Company irrevocably waive any objection that they now have or hereafter
irrevocably waive any objection that they now have or hereafter may have to the
laying of venue of any suit, action or proceeding brought in any such court and
further irrevocably waive any claim that any such suit, action or proceeding
brought in any such court has been brought in an inconvenient forum. Final
judgment against the Employee or the Company in any such suit shall be
conclusive and may be enforced in other jurisdictions by suit on the judgment, a
certified or true copy of which shall be conclusive evidence of the fact and the
amount of any liability of the Employee or the Company therein described, or by
appropriate proceedings under any applicable treaty or otherwise.


          10.  Conflicts of Interest. While employed by the Company, the
               ----------------------
Employee shall not, directly or indirectly, unless approved in writing by the
Company's board of directors:

               (a)    participate as an individual in any way in the benefits of
transactions with any of the Company's suppliers or Customers, including,
without limitation, having a financial interest in the Company's suppliers or
Customers, or making loans to, or receiving loans, from, the Company's suppliers
or Customers;

               (b)    realize a personal gain or advantage from a transaction in
which the Company has an interest or use information obtained in connection with
the Employee's employment with the Company for the Employee's personal advantage
or gain; or

               (c)    accept any offer to serve as an officer, director,
partner, consultant, manager with, or to be employed in a technical capacity by,
a person or entity which does business with the Company.

               (d)    As used in Section 10(a), (b) or (c), the Company also
includes its Affiliates.

                                       9
<PAGE>

          11.  Inventions, Ideas, Processes, and Designs. All inventions, ideas,
               -----------------------------------------
processes, programs, software, and designs (including all improvements) (i)
conceived or made by the Employee during the course of his employment with the
Company (whether or not actually conceived during regular business hours) and
for a period of six months subsequent to the termination or expiration of such
employment with the Company and (ii) related to the business of the Company,
shall be disclosed in writing promptly to the Company and shall be the sole and
exclusive property of the Company. An invention, idea, process, program,
software, or design including an improvement) shall be deemed related to the
business of the Company if (a) it was made with the Company's equipment,
supplies, facilities, or Confidential Information, (b) results from work
performed by the Employee for the Company, or (c) pertains to the current
business or demonstrably anticipated research or development work of the
Company. The Employee shall cooperate with the Company and its attorneys in the
preparation of patent and copyright applications for such developments and, upon
request, shall promptly assign all such inventions, ideas, processes, and
designs to the Company. The decision to file for patent or copyright protection
or to maintain such development as a trade secret shall be in the sole
discretion of the Company, and the Employee shall be bound by such decision. The
Employee shall provide as a schedule to this Employment Agreement, a complete
list of all inventions, ideas, processes, and designs, if any, patented or
unpatented, copyrighted or non-copyrighted, including a brief description, which
he made or conceived prior to his employment with the Company and which
therefore are excluded from the scope of this Agreement.

          12.  Indebtedness.  If,  during  the  course  of the  Employee's
               ------------
employment under this Agreement, the Employee becomes indebted to the Company
for any reason, the Company may, if it so elects, set off any sum due to the
Company from the Employee and collect any remaining balance from the Employee.


          13.  Assignability. The rights and obligations of the Company under
               -------------
this Agreement shall inure to the benefit of and be binding upon the successors
and assigns of the Company, provided that such successor or assign shall acquire
all or substantially all of the securities (via merger or otherwise) or assets
and business of the Company. The Employee's obligations hereunder may not be
assigned or alienated and any attempt to do so by the Employee will be void.

         14.   Severability.
               ------------

               (a)    The Employee expressly agrees that the character, duration
and geographical scope of the non-competition provisions set forth in this
Agreement are reasonable in light of the circumstances as they exist on the date
hereof. Should a decision, however, be made at a later date by a court of
competent jurisdiction that the character, duration or geographical scope of
such provisions is unreasonable, then it is the intention and the agreement of
the Employee and the Company that this Agreement shall be construed by the court
in such a manner as to impose only those restrictions on the Employee's conduct
that are reasonable in the light of the circumstances and as are necessary to
assure to the Company the benefits of this Agreement. If, in any judicial
proceeding, a court shall refuse to enforce all of the separate covenants deemed
included herein because taken together they are more extensive than necessary to
assure to the Company the intended benefits of this Agreement, it is expressly
understood and agreed by the parties hereto that the provisions of this
Agreement that, if eliminated, would permit the remaining separate provisions

                                       10
<PAGE>

to be enforced in such proceeding shall be deemed eliminated, for the purposes
of such proceeding, from this Agreement.

             (b) If any provision of this Agreement otherwise is deemed to be
invalid or unenforceable or is prohibited by the laws of the state or
jurisdiction where it is to be performed, this Agreement shall be considered
divisible as to such provision and such provision shall be inoperative in such
state or jurisdiction and shall not be part of the consideration moving from
either of the parties to the other. The remaining provisions of this Agreement
shall be valid and binding and of like effect as though such provision were not
included.

         15. Notices and Addresses. All notices, offers, acceptance and any
             ---------------------
other acts under this Agreement (except payment) shall be in writing, and shall
be sufficiently given if delivered to the addressees in person, by Federal
Express or similar receipted delivery, by facsimile delivery or, if mailed,
postage prepaid, by certified mail, return receipt requested, as follows:

         To the Company:         Dr. Gregory B. Holmes
                                 SFBC Analytical Laboratories, Inc.
                                 11190 Biscayne Blvd.
                                 North Miami, FL  33181
                                 Facsimile: (305) 895-8616

         With a copy to:         Michael D. Harris, Esq.
                                 Michael Harris, P.A.
                                 1645 Palm Beach Lakes Blvd.
                                 Suite 550
                                 West Palm Beach, FL  33401
                                 Facsimile (561) 478-1817

         To the Employee:        Dr. Allan Xu
                                 809 Fulton Avenue
                                 Lansdale, PA  19446

         With a copy to:         Donald R. Keer, Esq.
                                 Attorney at Law
                                 20 Brinker Drive
                                 Doylestown, PA  18901

or to such other address as either of them, by notice to the other may designate
from time to time. The transmission confirmation receipt from the sender's
facsimile machine shall be evidence of successful facsimile delivery. Time shall
be counted to, or from, as the case may be, the delivery in person or by
mailing.

         16. Counterparts.  This  Agreement  may be executed in one or more
             ------------
counterparts,  each of which shall be deemed an original but all of which
together shall constitute one and the same instrument. The execution of this
Agreement may be by actual or facsimile signature.

                                       11
<PAGE>

         17. Attorney's Fees. In the event that there is any controversy or
             ---------------
claim arising out of or relating to this Agreement, or to the interpretation,
breach or enforcement thereof, and any action or proceeding is commenced to
enforce the provisions of this Agreement, each party shall be responsible for
its own attorney's fee, costs and expenses.

         18. Governing Law. This Agreement and any dispute, disagreement, or
             -------------
issue of construction or interpretation arising hereunder whether relating to
its execution, its validity, the obligations provided therein or performance
shall be governed or interpreted according to the internal laws of the State of
Florida without regard to choice of law considerations.

         19. Entire Agreement. This Agreement constitutes the entire Agreement
             ----------------
between the parties and supersedes all prior oral and written agreements between
the parties hereto with respect to the subject matter hereof. Neither this
Agreement nor any provision hereof may be changed, waived, discharged or
terminated orally, except by a statement in writing signed by the party or
parties against which enforcement or the change, waiver discharge or termination
is sought.

         20. Additional Documents.  The parties hereto shall execute such
             --------------------
additional instruments as may be reasonably required by their counsel in order
to carry out the purpose and intent of this Agreement and to fulfill the
obligations of the parties hereunder.

         21. Section and Paragraph Headings.  The section and paragraph
             ------------------------------
headings  in this  Agreement  are for reference purposes only and shall not
affect the meaning or interpretation of this Agreement.


         22. Indemnity. The Company shall indemnify the Employee against
             ---------
expenses (including attorneys fees), judgment, fines, and amounts paid in
settlement arising out of his services as an officer or director of the Company
to the extent provided by the Florida Business Corporation Act. Notwithstanding
the indemnification provided for by this Section 22, such indemnity shall not
include any expenses, liabilities or losses incurred by the Employee relating to
or arising from any proceeding in which the Company asserts a direct claim (as
opposed to a stockholders' derivative action) against the Company, whether such
claim by the Company is termed a complaint, counterclaim, crossclaim,
third-party complaint or otherwise. Additionally, the Employee shall be covered
on the Parent's directors' and officers' liability insurance policy.



         23. Arbitration. Except for a claim for equitable relief pursuant to
             -----------
Section 9 hereof, any controversy, dispute or claim arising out of or relating
to this Agreement, or its interpretation, application, implementation, breach or
enforcement which the parties are unable to resolve by mutual agreement, shall
be settled by submission by either party of the controversy, claim or dispute to
binding arbitration in Miami-Dade County, Florida (unless the parties agree in
writing to a different location), before three arbitrators in accordance with
the rules of the American Arbitration Association then in effect. The decision
and award made by the arbitrators shall be final, binding and conclusive on all
parties hereto for all purposes, and judgment may be entered thereon in any
court having jurisdiction thereof.


              [Remainder of this page intentionally left blank.]

                                       12
<PAGE>

         IN WITNESS WHEREOF, the Company and the Employee have executed this
Agreement as of the date and year first above written.

                                    SFBC ANALYTICAL LABORATORIES, INC.

_______________________________

                                    By: /s/ Lisa Krinsky
_______________________________         --------------------------------
                                        Lisa Krinsky
                                        President

                                    EMPLOYEE:

________________________________

                                    By: /s/ Dr. Allan Xu
________________________________        ----------------------
                                        Dr. Allan Xu

                                       13
<PAGE>

                                EXHIBIT 4(f)-1
                                      TO
                             EMPLOYMENT AGREEMENT
                  BETWEEN SFBC ANALYTICAL LABORATORIES, INC.
                                      AND
                                 DR. ALLAN XU

                                    FORM OF
                                PROMISSORY NOTE
                                ---------------

$1,000,000.00                                                    August 20, 2001


FOR VALUE RECEIVED, the undersigned ("Maker") promises to pay to the order of
SFBC Analytical Laboratories, Inc. (the "Holder") the sum of One Million Dollars
($1,000,000.00). This Note shall bear interest at the minimum rate prescribed by
the Internal Revenue Service as of the date of this Note. Principal and interest
shall be due and payable in the manner set forth below.

Provided that the Maker is employed on a full-time basis by the Holder pursuant
to that certain Employment Agreement dated of even date herewith by and between
the Maker and the Holder, the Holder agrees that commencing August 20, 2002 and
on each August 20 thereafter, the Holder shall forgive Two Hundred Thousand
Dollars ($200,000.00) of the outstanding principal balance and accrued interest
until the Note is paid in full.

In the event that the Maker is no longer employed by the Holder for any reason
whatsoever, any remaining principal outstanding and accrued interest shall be
immediately due and payable in full after the termination of Maker's employment
(the "Due Date").

Interest on the remaining principal balance existing from and after the Due Date
shall accrue at the rate of eighteen (18%) percent per annum or such maximum
rate of interest allowable under the laws of the State of Florida.

Payments of remaining principal and default interest to be made by Maker shall
be in lawful money of the United States at the offices of the Holder at 11190
Biscayne Boulevard, Miami, FL 33181, or at such other place as may be designated
in writing by the Holder. This Note shall be considered in default when payment
required to be made hereunder shall not have been made by 5:00 p.m. Miami,
Florida time on the Due Date.

The Maker hereby waives demand, presentment, protest, notice of protest, and
notice of dishonor. No delay or omission on the part of the Holder in the
exercise of any right or remedy shall operate as a waiver thereof, and no single
or partial exercise by the Holder of any right or remedy shall preclude any
other or further exercise thereof of any other right or remedy.

All makers and endorsers now or hereafter becoming parties hereto jointly and
severally waive demand, presentment, notice of non-payment in protest and, if
this Note becomes in default and is placed into the hands of an attorney for
collection, to pay reasonable attorney's fees and all other

                                       14
<PAGE>

costs for making such collection, provided the Holder is the prevailing party.

This Note may not be changed or terminated orally, but only with an agreement in
writing, signed by the parties against whom enforcement of any waiver, change,
modification or discharge is sought, with such agreement being effective and
binding only upon the parties thereto.

This Note and the Maker's obligations hereunder are secured by a Pledge
Agreement between the Maker and the Holder and dated of even date herewith. This
Note shall be governed by and construed in accordance with the laws of the State
of Florida with respect to any and all actions related to the Note or the
enforcement of the Note without regard to conflict of law principles. In the
event that a provision of the Note is deemed prohibited by or held invalid under
applicable law, it shall be ineffective to the extent of the prohibition or
invalidity, but such prohibition or invalidity shall not invalidate the
remainder of such provisions or the remaining provisions of the Note. Wherever
in the Note reference is made to the Maker or the Holder, such reference shall
be deemed to include, as applicable, a reference to their respective successors
and assigns. The provisions of the Note shall be binding upon and shall inure to
the benefit of such successors and assigns.


                                           By:

                                               ------------------------
                                               Dr. Allan Xu

                                       15
<PAGE>

                                EXHIBIT 4(f)-2
                                --------------

                                      TO

                             EMPLOYMENT AGREEMENT
                  BETWEEN SFBC ANALYTICAL LABORATORIES, INC.
                                      AND
                                 DR. ALLAN XU

                                    FORM OF
                               PLEDGE AGREEMENT
                               ----------------


         THIS PLEDGE AGREEMENT (the "Agreement"),  made and entered into this
20th day of August, 2001, by and between Dr. Allan Xu ("Pledgor") and SFBC
Analytical Laboratories, Inc. (the "Lender").

         WHEREAS, Pledgor is indebted to Lender, which indebtedness is
represented by a promissory note (the "Note") from Pledgor to Lender dated of
even date herewith, in the original principal sum of One Million and No/100
dollars ($1,000,000.00) (the "Loan"); and

         WHEREAS, Lender has required the execution of this Agreement as
collateral security to secure the Loan;

         NOW, THEREFORE, in order to secure the Loan of the Lender as aforesaid,
and for good and valuable consideration, the receipt and adequacy of which are
acknowledged, the parties hereto agree as follows:

         1.  Security Interest.
             -----------------

             (a) As collateral security for the Loan as described above, Pledgor
hereby grants to Lender, and Lender shall have a security interest in __________
shares of common stock of the SFBC International, Inc. ("SFBC") issued in the
name of Pledgor (the "Shares"). Simultaneously with the execution of this
Agreement, Pledgor will deliver the Shares to Lender along with a duly executed
stock power, endorsed in blank.

             (b) Lender shall also have a security interest in all securities
and other property, rights or interests of any description at any time issued or
issuable as an addition to, in substitution or exchange for, or with respect to
the Shares, including without limitation, (i) shares issued as dividends or as
the result of any change in the name of Pledgor, or (ii) any reclassification,
or any split-up or other corporate reorganization, collectively referred to as
the "New Shares." Pledgor will promptly deliver to Lender duly executed stock
powers for any New Shares.

             (c) Pledgor represents and warrants that:
                 (i)     Pledgor is the sole beneficial and record owner of the
Shares;

                                       16
<PAGE>

                  (ii)   the Shares are free and clear of all liens, pledges,
charges, encumbrances, security interest or right or option of any third person
to purchase or otherwise acquire any of the Shares and Pledgor has the
unrestricted right to pledge the Shares as contemplated hereby;

                  (iii)  Pledgor possesses the voting rights in the Shares, and
will possess the voting rights, if any, in any New Shares free and clear of any
restrictions; and

                  (iv)   the Shares are not subject to any restriction on sale,
transfer, assignment or hypothecation other than such restrictions as arise out
of non-registration thereof or pursuant to that certain Lock-Up and
Indemnification Agreement dated of even date herewith by and between the Lender
and Pledgor (the "Lock-Up Agreement") a copy of which is set forth on Exhibit A.
                                                                      ---------

         2. Disposition of Collateral. As each installment of the Loan is
            -------------------------
repaid, the Lender shall release its rights and interests in 20% of the Shares
originally issued to Pledgor pursuant to that certain Merger Agreement dated of
even date herewith by and between the Lender and Pledgor; subject, however, to
                                                          -------  -------
any further restrictions set forth in the Lock-Up Agreement. Any released Shares
which are no longer subject to the restrictions of the Lock-Up Agreement, shall
be returned to Pledgor and this instrument shall be void and of no further
affect with respect to such released Shares.

         3. Default.
            -------

            (a) Pledgor shall be in default under this Agreement upon the
happening of any of the following events or conditions:

                (i)      The occurrence of a default under the Note;

                (ii)     Default in the payment or performance of any
obligation, covenant, agreement or liability under this Agreement;

                (iii)    Any warranty, representation, or statement made or
furnished to Lender by or on behalf of Pledgor or any other person in connection
with the Loan proves to have been false in any material respect when made or
furnished; or

                (iv)     Sale, or further encumbrance to or of any portion of
the Shares without the prior written consent of the Lender, or the making of any
levy, seizure, or attachment thereof or thereon.

            (b) The remedies of Lender as provided herein and in the other
documents and instruments executed in connection with the Loan, may be exercised
in any order and shall be cumulative and concurrent, and may be pursued singly,
successively, or together at the sole discretion of Lender, and may be exercised
as often as occasion therefor shall occur; and the failure to exercise any such
right or remedy shall in no event be construed as a waiver or release thereof.

                                       17
<PAGE>

            (c) Upon the occurrence of any such default or at any time
thereafter, Lender may, at its option, declare the Loan secured hereby
immediately due and payable without demand or notice of any kind and the same
thereupon shall immediately become and be due and payable without demand or
notice (but with such adjustments, if any, with respect to interest or other
charges and may be provided for in the Note or other writing evidencing such
Loan), and Lender shall have and may exercise from time to time any and all
rights and remedies of a secured party under the Uniform Commercial Code
(including, without limitation, the right to sell or liquidate any or all of the
Shares without notice and to apply the proceeds to the Loan in any order of
priority as the Lender sees fit) and any and all rights and remedies available
to it under any other applicable law, and in addition, all right, title and
interest in the Shares shall, at the option of the Lender, be transferred to
Lender and Lender shall in that event be and become the registered and
beneficial owner of the Shares subject to any applicable state and federal
securities laws, and Pledgor shall cease to have any further interest therein.

         4. Voting Rights. Voting rights with respect to the Shares shall remain
            -------------
with Pledgor until a default occurs and the Lender gives notice of such default
to Pledgor. The Lender may exercise any rights available under the Florida
Uniform Commercial Code, or, alternatively, Lender may, by notice to Pledgor,
transfer to Lender the pledged Shares at a rate equal to the average of the last
five days closing price of the Shares on the Nasdaq Stock Market or other
principal market. Upon receipt of such notice of Lender's election to transfer
the Shares, SFBC's transfer agent shall immediately transfer the Shares into the
name of Lender on the books and records of SFBC and issue new certificates
evidencing the transfer without any further action or consent necessary from
Pledgor (including a medallion signature guarantee) to effectuate the transfer.
This Agreement serves as authorization to SFBC's transfer agent to transfer the
Shares into the name of the Lender in the event of default.

         5. Miscellaneous Provisions.
            ------------------------

            (a) This Agreement shall remain in full force and effect as long as
any of the Loan shall remain unpaid in whole or in part.

            (b) Pledgor, without the written consent of Lender, shall not assign
or grant any other security interest in the Shares being pledged herein.

            (c) Until the Loan is paid in full or until the Shares are released,
transferred or otherwise disposed of pursuant to the terms of this Agreement, or
according to law, the Shares shall be kept by Lender in Miami-Dade County,
Florida.

            (d) In its discretion, the Lender may, at any time, take any one or
more of the following actions, without liability, except to account for property
actually received by it :

                (i)      after default hereunder, make any compromise or
settlement deemed advisable with respect to any of the Shares; and

                (ii)     take or release any other collateral as security for
the loan.

                                       18
<PAGE>

            (e) The Lender shall be under no duty to exercise or to withhold
the exercise of any of the rights, powers, privileges and options expressly or
implicitly granted to the Lender in this Agreement, and shall not be responsible
for any failure to do so or delay in so doing; nor shall the Lender be
responsible for any decline in value of any of the Shares.

            (f) The Lender shall exercise reasonable care in the custody and
preservation of the Shares and shall always be deemed to have exercised
reasonable care if it takes such action in that connection as Pledgor shall
reasonably request in writing, but no omission to comply with any request of
Pledgor shall, of itself, be deemed a failure to exercise reasonable care.
Without limiting the generality of the foregoing, the Lender shall have no
responsibility for ascertaining any maturities, calls, conversions, exchanges,
offers, tenders or similar matters relating to any of the Shares nor for
informing the undersigned with respect to any thereof. The Lender shall not be
bound to take any steps necessary to preserve any rights in the Shares against
prior parties, and Pledgor shall take all necessary steps for such purposes.

            (g) Pledgor shall promptly deliver to the Lender all written
notices, and shall promptly give the Lender written notice of any other notices
received by it with respect to the Shares.

            (h) Pledgor hereby notifies Lender's transfer agent that any New
Shares shall be delivered directly to the Lender until such time as Lender shall
otherwise notify the transfer agent.

         6. Entire Agreement.   This Agreement constitutes the entire Agreement
            ----------------
between the parties and supersedes all prior oral or written agreements
regarding the same subject matter.

         7. Severability.  In the event any parts of this Agreement are found to
            ------------
be void, the remaining provisions of this Agreement shall nevertheless be
binding with the same effect as though the void parts were deleted.

         8. Counterparts.  This Agreement may be executed in one or more
            ------------
counterparts, each of which shall be deemed an original but all of which
together shall constitute one and the same instrument. The execution of this
Agreement may be by actual or facsimile signature.

         9. Arbitration. Any controversy, dispute or claim arising out of or
            -----------
relating to this Agreement, or its interpretation, application, implementation,
breach or enforcement which the parties are unable to resolve by mutual
agreement, shall be settled by submission by either party of the controversy,
claim or dispute to binding arbitration in Miami, Florida, (unless the parties
agree in writing to a different location) before a single arbitrator in
accordance with the rules of the American Arbitration Association then in
effect. In any such arbitration proceeding the parties agree to provide all
discovery deemed necessary by the arbitrator. The decision and award made by the
arbitrator shall be final, binding and conclusive on all parties hereto for all
purposes, and judgment may be entered thereon in any court having jurisdiction
thereof.

                                       19
<PAGE>

         10. Benefit.  This Agreement shall be binding upon and inure to the
             -------
benefit of the parties hereto and their legal representatives, successors and
assigns.

         11. Notices and Addresses. All notices, offers, acceptance and any
             ---------------------
other acts under this Agreement (except payment) shall be in writing, and shall
be sufficiently given if delivered to the addressees in person, by Federal
Express or similar receipted delivery, by facsimile delivery or, if mailed,
postage prepaid, by certified mail, return receipt requested, as follows:

         The Lender:               Dr. Gregory B. Holmes
                                   SFBC Analytical Laboratories, Inc.
                                   11190 Biscayne Boulevard
                                   Miami, Florida 33181
                                                 Facsimile:  (305) 895-8616
         with a copy to:           Michael D. Harris, Esq.
                                   Michael Harris, P.A.
                                   1645 Palm Beach Lakes Boulevard
                                   Suite 550
                                   West Palm Beach, Florida  33401
                                   Facsimile:  (561) 478-1817

         The Pledgor:              Dr. Allan Xu
                                   c/o 113 Dickerson Road, Unit 6
                                   North Wales, Pennsylvania 19454
                                   Facsimile:  (215) 699-8848

or to such other address as either of them, by notice to the other may designate
from time to time. The transmission confirmation receipt from the sender's
facsimile machine shall be conclusive evidence of successful facsimile delivery.
Time shall be counted to, or from, as the case may be, the delivery in person or
by mailing.

         12. Attorney's Fees. In the event that there is any controversy or
             ---------------
claim arising out of or relating to this Agreement, or to the interpretation,
breach or enforcement thereof, and any action or proceeding is commenced to
enforce the provisions of this Agreement, the prevailing party shall be entitled
to a reasonable attorney's fee, including the fees on appeal, costs and
expenses.

         13. Governing Law.  This Agreement and any dispute, disagreement, or
             -------------
issue of construction or interpretation arising hereunder whether relating to
its execution, its validity, the obligations provided therein or performance
shall be governed or interpreted according to the laws of the State of Florida.

         14. Oral Evidence. This Agreement constitutes the entire Agreement
             -------------
between the parties and supersedes all prior oral and written agreements between
the parties hereto with respect to the subject matter hereof. Neither this
Agreement nor any provision hereof may be changed, waived, discharged or
terminated orally, except by a statement in writing signed by the party or
parties against which enforcement or the change, waiver discharge or termination
is sought.

                                       20
<PAGE>

         15. Additional Documents.  The parties hereto shall execute such
             --------------------
additional instruments as may be reasonably required by their counsel in order
to carry out the purpose and intent of this Agreement and to fulfill the
obligations of the parties hereunder.

         16. Section Headings.  Section headings herein have been inserted for
             ----------------
reference only and shall not be deemed to limit or otherwise affect, in any
matter, or be deemed to interpret in whole or in part any of the terms or
provisions of this Agreement.

IN WITNESS WHEREOF the parties hereto have set their hands and seals the day and
year first above written.


                                       SFBC Analytical Laboratories, Inc.

                                       By:
________________________________              --------------------------
                                              Lisa Krinsky, M.D.
                                              President
________________________________




                                       By:
________________________________              --------------------------
                                              Dr. Allan Xu


                                       21