It took weeks, for instance, to choose among a multitude of paint toxicity standards that local governments have set around the country. (Home Depot said it chose the strictest standard, set in Southern California.)

For now, most Eco Options products rely on independent certifications like Energy Star, which measure energy efficiency and is run by the Environmental Protection Agency and the Department of Energy.

Even though Energy Star is a widely accepted barometer for how much electricity a refrigerator or washing machine uses, it does not measure other factors, like how much energy was used to make the appliance in the first place or whether the manufacturer used recycled materials and encouraged its product to be recycled at the end of its life.

Home Depot is working with Scientific Certification Systems, a private company based in Emeryville, Calif., that audits and certifies company claims, to develop new broad-based standards. They will grade a product based on its environmental record over its entire life cycle — including the sustainability of its production process, its efficiency and longevity and how it can be recycled when it is no longer useful.

But until some kind of standard can be worked out, Mr. Jarvis and his team are forced to work their way through the thicket of claims.

They are currently considering a rug that is made out of corn fiber instead of nylon, one that the manufacturer is heralding as a natural, earth-friendly product. Corn is natural, Mr. Jarvis acknowledged, but he said he was concerned about the buildup of phosphates in the Gulf of Mexico coming off the Mississippi River from corn farming, as well as the fuel it takes to run the tractors in corn fields and to transport the corn.