Greenpeace recently released the eighth edition of its “Guide to Greener Electronics,” in which the environmental group rates 18 companies’ green efforts on a scale of one to 10.

Not surprisingly, the group’s rating criteria is tough indeed, evaluating specific practices that are based on three fundamental questions.

1) Has the company cleaned up its products by eliminating hazardous substances;

2) Does the company take back and recycle its products responsibly once the products become obsolete; and

3) Has the company improved its corporate policies and practices with respect to climate and energy.

That last criteria is a new addition to the evaluation process, and tougher standards caused all of the companies’ scores to fall this time around. Even the two highest-ranked companies on the list – Sony Ericsson and Sony – scored only 5.1 out of 10.

The report is updated quarterly; in the last edition, Samsung and Toshiba tied for first, but they’ve now fallen to fourth and sixth, respectively. Sharp, Philips, and LG landed on the lower half of the list. And, with a rating of just 0.8, Nintendo took bottom honors.

To view the complete report, go to Greenpeace.com/electronics.