| 7.
     | 
    Income
    (Loss) Per Share | 
 
 
  
Basic
income (loss) per share is calculated based on the weighted-average number of outstanding common shares during the applicable
period. Diluted income (loss) per share is based on the weighted-average number of outstanding common shares plus the weighted-average
number of potential outstanding common shares. In periods where they are anti-dilutive, such amounts are excluded from the calculations
of dilutive earnings per share. The following table reconciles the income (loss) and average share amounts used to compute both
basic and diluted income (loss) per share: 
  
    |   | 
  | 
    Three
    Months Ended | 
  | 
  | 
    Six
    Months Ended | 
  | 
 
    |   | 
  | 
    June
    30, | 
  | 
  | 
    June
    30, | 
  | 
 
    |   | 
  | 
    (Unaudited) | 
  | 
  | 
    (Unaudited) | 
  | 
 
    | (Amounts
    in Thousands, Except for Per Share Amounts) | 
  | 
    2019 | 
  | 
  | 
    2018 | 
  | 
  | 
    2019 | 
  | 
  | 
    2018 | 
  | 
 
    | Net
    income (loss) attributable to Perma-Fix Environmental Services, Inc., common stockholders: | 
  | 
      | 
  | 
  | 
  | 
      | 
  | 
  | 
  | 
      | 
  | 
  | 
  | 
      | 
  | 
  | 
 
    | Income
    (loss) from continuing operations, net of taxes | 
  | 
    $ | 
373 | 
  | 
  | 
    $ | 
788 | 
  | 
  | 
    $ | 
(177 | 
) | 
  | 
    $ | 
1,040 | 
  | 
 
    | Net
    loss attributable to non-controlling interest | 
  | 
      | 
(31 | 
) | 
  | 
      | 
(28 | 
) | 
  | 
      | 
(61 | 
) | 
  | 
      | 
(68 | 
) | 
 
    | Income
    (loss) from continuing operations attributable to Perma-Fix Environmental Services, Inc. common stockholders | 
  | 
      | 
404 | 
  | 
  | 
      | 
816 | 
  | 
  | 
      | 
(116 | 
) | 
  | 
      | 
1,108 | 
  | 
 
    | Loss
    from discontinuing operations attributable to Perma-Fix Environmental Services, Inc. common stockholders | 
  | 
      | 
(115 | 
) | 
  | 
      | 
(206 | 
) | 
  | 
      | 
(267 | 
) | 
  | 
      | 
(363 | 
) | 
 
    | Net
    income (loss) attributable to Perma-Fix Environmental Services, Inc. common stockholders | 
  | 
    $ | 
289 | 
  | 
  | 
    $ | 
610 | 
  | 
  | 
    $ | 
(383 | 
) | 
  | 
    $ | 
745 | 
  | 
 
    |   | 
  | 
      | 
  | 
  | 
  | 
      | 
  | 
  | 
  | 
      | 
  | 
  | 
  | 
      | 
  | 
  | 
 
    | Basic
    income (loss) per share attributable to Perma-Fix Environmental Services, Inc. common stockholders | 
  | 
    $ | 
.02 | 
  | 
  | 
    $ | 
.05 | 
  | 
  | 
    $ | 
(.03 | 
) | 
  | 
    $ | 
.06 | 
  | 
 
    |   | 
  | 
      | 
  | 
  | 
  | 
      | 
  | 
  | 
  | 
      | 
  | 
  | 
  | 
      | 
  | 
  | 
 
    | Diluted
    income (loss) per share attributable to Perma-Fix Environmental Services, Inc. common stockholders | 
  | 
    $ | 
.02 | 
  | 
  | 
    $ | 
.05 | 
  | 
  | 
    $ | 
(.03 | 
) | 
  | 
    $ | 
.06 | 
  | 
 
    |   | 
  | 
      | 
  | 
  | 
  | 
      | 
  | 
  | 
  | 
      | 
  | 
  | 
  | 
      | 
  | 
  | 
 
    | Weighted
    average shares outstanding: | 
  | 
      | 
  | 
  | 
  | 
      | 
  | 
  | 
  | 
      | 
  | 
  | 
  | 
      | 
  | 
  | 
 
    | Basic
    weighted average shares outstanding | 
  | 
      | 
12,054 | 
  | 
  | 
      | 
11,813 | 
  | 
  | 
      | 
12,008 | 
  | 
  | 
      | 
11,780 | 
  | 
 
    | Add:
    dilutive effect of stock options | 
  | 
      | 
68 | 
  | 
  | 
      | 
100 | 
  | 
  | 
      | 
─ | 
  | 
  | 
      | 
69 | 
  | 
 
    | Diluted
    weighted average shares outstanding | 
  | 
      | 
12,122 | 
  | 
  | 
      | 
11,913 | 
  | 
  | 
      | 
12,008 | 
  | 
  | 
      | 
11,849 | 
  | 
 
    |   | 
  | 
      | 
  | 
  | 
  | 
      | 
  | 
  | 
  | 
      | 
  | 
  | 
  | 
      | 
  | 
  | 
 
    | Potential
    shares excluded from above weighted average share calcualtions due to their anti-dilutive effect include: | 
  | 
      | 
  | 
  | 
  | 
      | 
  | 
  | 
  | 
      | 
  | 
  | 
  | 
      | 
  | 
  | 
 
    | Upon
    exercise of options | 
  | 
      | 
113 | 
  | 
  | 
      | 
100 | 
  | 
  | 
      | 
186 | 
  | 
  | 
      | 
100 | 
  | 
 
 
 |