PROMISSORY NOTE

FOR VALUE RECEIVED, the undersigned PERMA-FIX ENVIRONMENTAL SERVICES, INC., a Delaware corporation (“Borrower”) promises to pay to the order of WILLIAM N. LAMPSON, an individual (“Lampson”), and DIEHL RETTIG, an individual (“Rettig”) (Lampson and Rettig are collectively, the “Lenders”), for the account of the Lenders as directed by the Lenders in writing to the Borrower at KeyBank National Association (“KeyBank”), located at 23 W. Kennewick Avenue, Kennewick, Washington 99336, or at such other place as may be designated in writing by the Lenders, the principal sum of THREE MILLION AND 00/100 DOLLARS ($3,000,000.00), together with interest thereon at the interest rates hereinafter stated, payable as set forth below.

Unless otherwise defined herein, all terms defined or referenced in that certain Loan and Securities Purchase Agreement of even date herewith between the Borrower and the Lenders (the “Loan Agreement”) will have the same meanings herein as therein.

Interest on this Note will be paid at the interest rate equal to the Libor Rate plus four and one-half percent (4.5%) per annum, adjusted on each date on which a change in the LIBOR Rate occurs (the “Interest Rate”).  “LIBOR Rate” means the rate per annum calculated by the Lenders in good faith, which Lenders determine with reference to the rate per annum (rounded to the next higher whole multiple of 1/16% if such rate is not such a multiple) at which deposits in United States dollars are offered by prime banks in the London interbank Eurodollar market two Business Days prior to the day on which such rate is calculated by KeyBank, based on a 30 day maturity; provided, however, that LIBOR Rate shall in no event be less than one and one-half percent (1.50%).  On the date the Note is signed by Borrower and continuing until the end of such month, the LIBOR Rate shall be the LIBOR Rate determined by the Lenders on the first day of such month, or if the first day of such month is not a Business Day, then as determined by the Lenders on the Business Day immediately preceding the first day of such month, effective as of the first day of such month; thereafter, the LIBOR Rate shall be adjusted by the Lenders on the first day of each succeeding month, or if the first day of the month is not a Business Day, then as determined by Lenders on the Business Day immediately preceding the first day of the month, effective as of the first day of the month.  “Business Day” means a day of the year on which banks are not required or authorized to close in Cleveland, Ohio, and, if the applicable Business Day relates to determination of the LIBOR Rate, a day on which dealings are carried on in the London interbank Eurodollar market.

Commencing on June 8, 2009, and on the 8th day of each