EXHIBIT
“B”


 


NEITHER THIS SECURITY NOR THE SECURITIES INTO
WHICH THIS SECURITY IS EXERCISABLE HAVE BEEN REGISTERED WITH THE SECURITIES AND EXCHANGE COMMISSION OR THE SECURITIES COMMISSION
OF ANY STATE IN RELIANCE UPON AN EXEMPTION FROM REGISTRATION UNDER THE SECURITIES ACT OF 1933, AS AMENDED (THE “ACT”),
AND, ACCORDINGLY, MAY NOT BE OFFERED OR SOLD EXCEPT PURSUANT TO AN EFFECTIVE REGISTRATION STATEMENT UNDER THE ACT OR PURSUANT TO
AN AVAILABLE EXEMPTION FROM, OR IN A TRANSACTION NOT SUBJECT TO, THE REGISTRATION REQUIREMENTS OF THE SECURITIES ACT AND IN ACCORDANCE
WITH APPLICABLE STATE SECURITIES LAWS AS EVIDENCED BY A LEGAL OPINION OF COUNSEL TO THE TRANSFEROR REASONABLY ACCEPTABLE TO THE
COMPANY TO SUCH EFFECT, THE SUBSTANCE OF WHICH SHALL BE REASONABLY ACCEPTABLE TO THE COMPANY.


 


COMMON STOCK PURCHASE WARRANT


 


To Purchase 60,000 Shares


 


of Common Stock of


 


PERMA-FIX ENVIRONMENTAL SERVICES, INC.


 


April 1, 2019


 


THIS COMMON STOCK PURCHASE
WARRANT (the “Warrant”) CERTIFIES that, for value received, ROBERT FERGUSON, an individual (the “Holder”),
is entitled, upon the terms and subject to the limitations on exercise and the conditions hereinafter set forth, at any time on
or after six months from the date of issuance of this Warrant (the “Initial Exercise Date”) and on or prior to the
fifth anniversary of the date of this Warrant (the “Termination Date”) but not thereafter, to subscribe for and purchase
from Perma-Fix Environmental Services, Inc., a Delaware corporation (the “Company”), up to 60,000 shares (the “Warrant
Shares”) of common stock, par value $0.001 per share, of the Company (“Common Stock”). The purchase price of
one share of Common Stock (the “Exercise Price”) under this Warrant is $3.51, which is the closing bid price for a
share of the Company’s Common Stock on Nasdaq.com immediately preceding the execution of the Loan Agreement (as defined below),
subject to adjustment hereunder. The Exercise Price and the number of Warrant Shares for which the Warrant is exercisable
shall be subject to adjustment as provided herein. This Warrant shall be subject to, and the capitalized terms used and not
otherwise defined herein shall have the meanings set forth in, that certain Loan and Securities Purchase Agreement (the “Loan
Agreement”), dated April 1, 2019, between the Company and the Holder.


 


1. Title to Warrant.
Prior to the Termination Date and subject to compliance with applicable laws and the terms of this Warrant, this Warrant and all
rights hereunder are transferable, in whole or in part, at the office or agency of the Company by the Holder in person or by duly
authorized attorney, upon surrender of this Warrant together with the Assignment Form annexed hereto properly endorsed; provided,
however, that the assignee is an accredited investor, as such term is defined in Rule 501 promulgated under the Securities Act
of 1933, as amended (the Securities Act”). The transferee shall have signed an investment letter in form and substance reasonably
satisfactory to the Company and its counsel and in compliance with the terms and provisions of paragraph 5 of this Warrant.


 




    	 



    	 



    

 


2. Authorization of Shares.
The Company covenants that all Warrant Shares which may be issued upon the exercise of the purchase rights represented by this
Warrant will, upon exercise of the purchase rights represented by this Warrant, be duly authorized, validly issued, fully paid
and nonassessable and free from all taxes, liens and charges in respect of the issue thereof (other than taxes in respect of any
transfer occurring contemporaneously with such issue and subject to compliance with applicable federal and state securities laws).


 


3. Exercise of Warrant.


 


	 	3.1	Procedure. Exercise of the purchase rights represented by this Warrant may be made at any time or times on or after the Initial Exercise Date and on or before the Termination Date by satisfying each of the following: 


 


	 	(a)	delivery to the Company of a duly executed facsimile copy of the Notice of Exercise Form attached hereto; 
	 	 	 
	 	(b)	surrender of this Warrant to the Company and receipt by the Company of this Warrant within 10 days of the date the Notice of Exercise is delivered to the Company; 
	 	 	 
	 	(c)	receipt by the Company of payment of the aggregate Exercise Price of the shares to be purchased, with such payment made by wire transfer or cashier’s check drawn on a United States bank;
	 	 	 
	 	(d)	receipt by the Company of such written investment representations and warranties by the Holder as the Company may reasonably request in accordance with paragraph 8 of the Loan Agreement.


 


This Warrant will be deemed to have
been exercised (the “Exercise Date”) on the later of (x) the date the Notice of Exercise is delivered to the Company
by facsimile copy, (y) the date this Warrant is received by the Company, and (z) the date the Exercise Price is received by the
Company.


 


	 	3.2	Issuance of Warrant Shares. Certificates representing the shares of Common Stock purchased hereunder will be delivered to the Holder within 10 Trading Days following the Exercise Date (“Warrant Share Delivery Date”). The Warrant Shares shall be deemed to have been issued, and Holder or any other person so designated to be named therein shall be deemed to have become a holder of record of such shares for all purposes, as of the date the Exercise Date. If the Company fails to deliver to the Holder a certificate or certificates representing the Warrant Shares pursuant to this paragraph 3.2 within 20 Trading Days following the Warrant Share Delivery Date, then the Holder will have the right to rescind such exercise. If this Warrant shall have been exercised in part, the Company shall, at the time of delivery of the certificate or certificates representing Warrant Shares, deliver to Holder a new Warrant evidencing the rights of Holder to purchase the unpurchased Warrant Shares called for by this Warrant, which new Warrant shall in all other respects be identical with this Warrant.



 






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	 	3.3	Charges, Taxes and Expenses. Issuance of certificates for Warrant Shares shall be made without charge to the Holder for any issue or transfer tax or other incidental expense in respect of the issuance of such certificate, all of which taxes and expenses shall be paid by the Company, and such certificates shall be issued in the name of the Holder or in such name or names as may be directed by the Holder; provided, however, that if certificates for Warrant Shares are to be issued in a name other than the name of the Holder, this Warrant when surrendered for exercise shall be accompanied by the Assignment Form attached hereto duly executed by the Holder; and the Company may require, as a condition thereto, the payment of a sum sufficient to reimburse it for any transfer tax incidental thereto. 


 


4. No Fractional Shares
or Scrip. No fractional shares or scrip representing fractional shares shall be issued upon the exercise of this Warrant. As
to any fraction of a share which Holder would otherwise be entitled to purchase upon such exercise, the Company shall pay a cash
adjustment in respect of such final fraction in an amount equal to such fraction multiplied by the Exercise Price.


 


5. Transfer, Division
and Combination.


 


	 	5.1	Transfer. Subject to compliance with any applicable securities laws and the conditions set forth in paragraphs 1 and 5.4 hereof and to the provisions of paragraph 8.8 of the Loan Agreement, this Warrant and all rights hereunder are transferable, in whole or in part, upon surrender of this Warrant at the principal office of the Company, together with a written assignment of this Warrant substantially in the form attached hereto duly executed by the Holder or its agent or attorney and funds sufficient to pay any transfer taxes payable upon the making of such transfer. Promptly following such surrender and, if required, such payment, the Company shall execute and deliver a new Warrant or Warrants in the name of the assignee or assignees and in the denomination or denominations specified in such instrument of assignment, and shall issue to the assignor a new Warrant evidencing the portion of this Warrant not so assigned, and this Warrant shall promptly be cancelled.
	 	 	 
	 	5.2	Division; Combination. This Warrant may be divided or combined with other Warrants upon presentation hereof at the aforesaid office of the Company, together with a written notice specifying the names and denominations in which new Warrants are to be issued, signed by the Holder or its agent or attorney. Subject to compliance with paragraph 5.1, as to any transfer which may be involved in such division or combination, the Company shall execute and deliver a new Warrant or Warrants in exchange for the Warrant or Warrants to be divided or combined in accordance with such notice.
	 	 	 
	 	5.3	Issuance; Records. The Company shall prepare, issue and deliver at its own expense (other than transfer taxes) the new Warrant or Warrants under this paragraph 5. The Company agrees to maintain, at its aforesaid office, books for the registration and the registration of transfer of the Warrants.



 






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	 	5.4	Securities Laws Compliance. If, at the time of the surrender of this Warrant in connection with any transfer of this Warrant, the transfer of this Warrant shall not be registered pursuant to an effective registration statement under the Securities Act and under applicable state securities or blue sky laws, the Company may require, as a condition of allowing such transfer, that: 


 


	 	(a)	the Holder or transferee of this Warrant, as the case may be, furnish to the Company a written opinion of counsel (which opinion shall be in form, substance and scope customary for opinions of counsel in comparable transactions and satisfactory to the Company and its counsel) to the effect that such transfer may be made without registration under the Securities Act and under applicable state securities or blue-sky laws;
	 	 	 
	 	(b)	the holder or transferee execute and deliver to the Company an investment letter in form and substance acceptable to the Company; and
	 	 	 
	 	(c)	the transferee be an “accredited investor” as defined in Rule 501 promulgated under the Securities Act or a qualified institutional buyer as defined in Rule 144A under the Securities Act.


 


6. No Rights as Shareholder
until Exercise. This Warrant does not entitle the Holder to any voting rights or other rights as a shareholder of the Company
prior to the exercise hereof. The Warrant Shares shall be deemed to have been issued, and Holder or any other person so designated
to be named therein shall be deemed to have become a holder of record of such shares for all purposes, as of the close of business
on the date the Exercise and all taxes required to be paid by the Holder, if any, pursuant to paragraph 3.3 prior to the issuance
of such shares, have been paid.


 


7. Loss, Theft, Destruction
or Mutilation of Warrant. The Company covenants that upon receipt by the Company of evidence reasonably satisfactory to it
of the loss, theft, destruction or mutilation of this Warrant or any stock certificate relating to the Warrant Shares, and in case
of loss, theft, or destruction of indemnity or security reasonably satisfactory to it (which, in the case of the Warrant, shall
not include the posting of any bond), and upon surrender and cancellation of such Warrant or stock certificate, if mutilated, the
Company will make and deliver a new Warrant or stock certificate of like tenor and dated as of such cancellation, in lieu of such
Warrant or stock certificate.


 


8. Saturdays, Sundays,
Holidays, etc. If the last or appointed day for the taking of any action or the expiration of any right required or granted
herein shall be a Saturday, Sunday or a legal holiday, then such action may be taken or such right may be exercised on the next
succeeding day not a Saturday, Sunday or legal holiday.


 






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9. Adjustments
of Exercise Price and Warrant Shares. The number and kind of securities purchasable upon the exercise of this Warrant
and the Exercise Price shall be subject to adjustment from time to time upon the happening of any of the following. If the
Company:


 


	(a)	pays a dividend in shares of Common Stock to all holders of its outstanding Common Stock,
	 	 
	(b)	subdivides or stock splits its outstanding shares of Common Stock into a greater number of shares,
	 	 
	(c)	combines its outstanding shares of Common Stock into a smaller number of shares of Common Stock, or
	 	 
	(d)	issues any shares of its capital stock in a reclassification of the Common Stock,


 


then the number of Warrant
Shares purchasable upon exercise of this Warrant immediately prior thereto shall be adjusted so that the Holder shall be entitled
to receive the kind and number of Warrant Shares or other securities of the Company which it would have owned or have been entitled
to receive had such Warrant been exercised in advance thereof. Upon each such adjustment of
the kind and number of Warrant Shares or other securities of the Company which are purchasable hereunder, the Holder shall thereafter
be entitled to purchase the number of Warrant Shares or other securities resulting from such adjustment at an Exercise Price per
Warrant Share or other security obtained by multiplying the Exercise Price in effect immediately prior to such adjustment by the
number of Warrant Shares purchasable pursuant hereto immediately prior to such adjustment and dividing by the number of Warrant
Shares or other securities of the Company that are purchasable pursuant hereto immediately after such adjustment. An adjustment
made pursuant to this paragraph shall become effective immediately after the effective date of such event retroactive to the record
date, if any, for such event.


 


10. Reclassification,
Merger, Consolidation or Disposition of Assets. If the Company shall reclassify its capital stock, consolidate or merge with
or into another corporation (where the Company is not the surviving corporation), or
sell, transfer or otherwise dispose of all or substantially all of its property, assets or business to another corporation and,
pursuant to the terms of such reclassification, merger, consolidation or disposition of assets, shares of Common Stock of the successor
or acquiring corporation, or any cash, shares of stock or other securities or property of any nature whatsoever (including warrants
or other subscription or purchase rights) in addition to or in lieu of Common Stock of the successor or acquiring corporation (“Other
Property”), are to be received by or distributed to the holders of Common Stock of the Company, then the Holder shall have
the right thereafter to receive. upon exercise of this Warrant, the number of shares of Common Stock of the successor or acquiring
corporation or of the Company, if it is the surviving corporation, and Other Property receivable upon or as a result of such reclassification,
merger, consolidation or disposition of assets by a Holder of the number of shares of Common Stock for which this Warrant is exercisable
immediately prior to such event. In case of any such reclassification, merger, consolidation or disposition of assets, the successor
or acquiring corporation (if other than the Company) shall expressly assume the due and punctual observance and performance of
each and every covenant and condition of this Warrant to be performed and observed by the Company and all the obligations and liabilities
hereunder, subject to such modifications as may be deemed appropriate (as determined in good faith by resolution of the Board of
Directors of the Company) in order to provide for adjustments of Warrant Shares for which this Warrant is exercisable which shall
be as nearly equivalent as practicable to the adjustments provided for in this paragraph 10. For purposes of this paragraph 10,
“Common Stock of the successor or acquiring corporation” shall include stock of such corporation of any class which
is not preferred as to dividends or assets over any other class of stock of such corporation and which is not subject to redemption
and shall also include any evidences of indebtedness, shares of stock or other securities which are convertible into or exchangeable
for any such stock, either immediately or upon the arrival of a specified date or the happening of a specified event and any warrants
or other rights to subscribe for or purchase any such stock. The foregoing provisions of this paragraph 10 shall similarly apply
to successive reclassifications, mergers, consolidations or disposition of assets.


 






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11. Notice of Adjustment.
Whenever the number of Warrant Shares or number or kind of securities or other property purchasable upon the exercise of this Warrant
or the Exercise Price is adjusted, as herein provided, the Company shall give notice thereof to the Holder, which notice shall
state the number of Warrant Shares (and other securities or property) purchasable upon the exercise of this Warrant and the Exercise
Price of such Warrant Shares (and other securities or property) after such adjustment, setting forth a brief statement of the facts
requiring such adjustment and setting forth the computation by which such adjustment was made.


 


12. Authorized Shares.
The Company covenants that during the period this Warrant is outstanding, it will reserve from its authorized and unissued Common
Stock a sufficient number of shares to provide for the issuance of the Warrant Shares upon the exercise of any purchase rights
under this Warrant. The Company further covenants that its issuance of this Warrant shall constitute full authority to its officers
who are charged with the duty of executing stock certificates to execute and issue the necessary certificates for the Warrant Shares
upon the exercise of the purchase rights under this Warrant. The Company will take all such reasonable action as may be necessary
to assure that such Warrant Shares may be issued as provided herein without violation of any applicable law or regulation, or of
any requirements of the Trading Market upon which the Common Stock may be listed.


 


13. Miscellaneous.


 


	 	13.1	Jurisdiction/Venue. All questions concerning the construction, validity, enforcement and interpretation of this Warrant shall be governed by and construed and enforced in accordance with the internal laws of the State of Delaware, without regard to the principles of conflicts of law thereof. Each party hereby irrevocably submits to the exclusive jurisdiction of the state and federal courts sitting in the state of Delaware, for the adjudication of any dispute hereunder or in connection herewith or with any transaction contemplated hereby or discussed herein and hereby irrevocably waives, and agrees not to assert in any suit, action or proceeding, any claim that it is not personally subject to the jurisdiction of any such court, that such suit, action or proceeding is improper or inconvenient venue for such proceeding.
	 	 	 
	 	13.2	Restrictions. The Holder acknowledges that the Company has no obligation to register this Warrant or the Warrant Shares with the Securities and Exchange Commission or any state securities agency, and the Warrant Shares acquired upon the exercise of this Warrant, if not registered, will have restrictions upon resale imposed by state and federal securities laws.



 






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	 	13.3	Notices. Any notice, request or other document required or permitted to be given or delivered to the Holder by the Company shall be delivered in accordance with the notice provisions of the Loan Agreement.
	 	 	 
	 	13.4	Limitation of Liability. No provision of this Warrant, in the absence of any affirmative action by Holder to exercise this Warrant or purchase Warrant Shares, and no enumeration herein of the rights or privileges of Holder, shall give rise to any liability of Holder for the purchase price of any Common Stock exercisable under this Warrant or as a stockholder of the Company, whether such liability is asserted by the Company or by creditors of the Company.
	 	 	 
	 	13.5	Successors and Assigns. Subject to applicable securities laws and the terms of this Warrant, this Warrant and the rights and obligations evidenced hereby shall inure to the benefit of and be binding upon the successors of the Company and the successors and permitted assigns of Holder. The provisions of this Warrant are intended to be for the benefit of all Holders from time to time of this Warrant and shall be enforceable by any such Holder or holder of Warrant Shares.
	 	 	 
	 	13.6	Amendment. This Warrant may be modified or amended or the provisions hereof waived with the written consent of the Company and the Holder.
	 	 	 
	 	13.7	Severability. Wherever possible, each provision of this Warrant shall be interpreted in such manner as to be effective and valid under applicable law, but if any provision of this Warrant shall be prohibited by or invalid under applicable law, such provision shall be ineffective to the extent of such prohibition or invalidity, without invalidating the remainder of such provisions or the remaining provisions of this Warrant.
	 	 	 
	 	13.8	Headings. The headings used in this Warrant are for the convenience of reference only and shall not, for any purpose, be deemed a part of this Warrant.


 


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IN WITNESS WHEREOF, the
Company has caused this Warrant to be executed by its officer thereunto duly authorized.


 


Dated: April 1, 2019


 





	 	PERMA-FIX ENVIRONMENTAL SERVICES, INC.
	 	 
	 	By:	/s/ Ben Naccarato
	 	Name:	Ben Naccarato
	 	Title:	CFO







 





	 	(“PESI)
	 	 
	 	/s/ Robert Ferguson
	 	ROBERT FERGUSON, an individual
	 	 
	 	(the “Holder”)







 




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NOTICE OF EXERCISE


 


To: Perma-Fix Environmental Services, Inc.


 


(1) The undersigned hereby
elects to purchase ________ Warrant Shares of the Company pursuant to the terms of the attached Warrant (only if exercised in full),
and tenders herewith payment of the exercise price in full, together with all applicable transfer taxes, if any. Payment shall
take the form of in lawful money of the United States.


 


(2) Please issue a certificate
or certificates representing said Warrant Shares in the name of the undersigned or in such other name as is specified below:


 


	 		 


 


(3) The Warrant Shares
shall be delivered to the following:


 


	 	 	 
	 		 
	 		 


 


(4) Accredited Investor.
The undersigned is an “accredited investor” as defined in Regulation D under the Securities Act of 1933, as amended.


 


	 	[PURCHASER]
	 	 
	 	By:	                    
	 	Name:	 
	 	Title:	 
	 	 	 
	 	Dated:	 


 




    	 



    	 



    

 


ASSIGNMENT
FORM


 


(To
assign the foregoing warrant, execute


this
form and supply required information.


Do
not use this form to exercise the warrant.)


 


FOR
VALUE RECEIVED, the foregoing Warrant and all rights evidenced thereby are hereby assigned to


 


_______________________________________________
whose address is


 


_______________________________________________________________.


 


_______________________________________________________________


 


Dated:
______________, _______


 


 


	 	Holder’s
    Signature:		 
	 	 	 	 
	 	Holder’s
    Address:		 
	 	 	 	 
	 	 	 	 


 


	Signature
    Guaranteed:	 	


 


NOTE:
The signature to this Assignment Form must correspond with the name as it appears on the face of the Warrant, without alteration
or enlargement or any change whatsoever, and must be guaranteed by a bank or trust company. Officers of corporations and those
acting in a fiduciary or other representative capacity should file proper evidence of authority to assign the foregoing Warrant.