For a century, the Good Housekeeping Seal has guided consumers to wise purchases.

Now, the magazine is hoping it will lead them to environmentally friendly ones as well.

In its April issue, editor-in-chief Rosemary Ellis announces the magazine will add a second, Green Good Housekeeping Seal to its quality-assurance arsenal. Good Housekeeping stepped into the green movement when it found its readers were interested in buying eco-friendly products, but found themselves lost in a marketplace of green garble, Ellis said.

"Marketers were slapping a lot of words on products sometimes legitimately, no doubt, sometimes not so legitimately," Ellis said, ticking off labels like "natural" and "organic."

Products that have already won the original seal issued by the Good Housekeeping Research Institute can now ask to also be evaluated for the green seal.

The magazine, with a circulation of 25 million, has partnered with the Santa Barbara, Calif.-based environmental consultancy firm Brown & Wilmanns Environmental to develop its green criteria.

The magazine and the firm will look at a product's composition, manufacturing and packaging before deciding if it will receive the green seal. Separate criteria will be developed for different categories of products, including appliances, electronics and health and beauty aids.

The Good Housekeeping Seal of Approval debuted in 1909 and by the end of 1910, 200 products had earned the label. By 1941 it was renamed the Good Housekeeping Seal and has since gone through several changes. Today, about 5,000 products have the seal, which is issued for two years, after which products have to request a re-evaluation.

The green seal has the same sleek look as the original Good Housekeeping Seal, but is a dark-green color and has leaves on either side.

Determining what products get the green thumbs-up will include evaluating health value and toxicity, said Michael Brown, of Brown and Wilmanns.

"It's a combination of looking at the materials that go into the product, aspects of waste, energy use, water use and certainly the potential health impacts associated with the product," said Brown, whose firm will train Good Housekeeping researchers to test products against the decided green criteria.

San Francisco writer Jennifer Roberts, author of "Good Green Kitchens," said consumers need more direct labeling to make clear choices when they're in the grocery aisle - and the new seal could fill that void.

"There is so much greenwashing that's going on," Roberts said. "People are becoming more and more aware and cynical.

"The potential for an organization that does have a good reputation and stands behind it, that could be good for consumers."

Another key to success will be giving consumers a place to find and review the green criteria, said Boulder, Colo.-based green building expert David Johnston, author of "Green From the Ground Up."

"Transparency is fundamental to making this really valuable," Johnston said. "If that's there and they're rigorous, then this is performing a service. It takes someone of their scale to make it work."