As director of Element, a brand of environmentally conscious hotels being developed by Starwood Hotels & Resorts World Wide Inc., Nicholas Lakas picks his way across a landscape of so-called green products each time he steps into his office.

Among the items: salt and pepper shakers billed as 100% recyclable; piles of towels and sheets made with organically grown fibers; boxes of organic snacks; and a countertop slab made from recycled materials.

"We get so many products, so many phone calls," Mr. Lakas says. "I have nowhere to put it, and we are always looking at it and evaluating it." He is shopping for environmentally friendly products -- from plates and light bulbs to heating and air-conditioning systems -- to be used in the first hotel in the planned chain of 90. Starwood announced the brand a year ago, pitching it as an environmentally and socially conscious hotel room at a reasonable price.

The Hilton Portland & Executive Tower in Oregon meets the Green Seal standard; cards issued by the "Green" Hotels Association; a hotel chair by Furnature, billed as organic and chemical-free. As more hotels try to become more environmentally friendly, in part to satisfy customers they say are increasingly demanding it, they find themselves in unfamiliar territory cluttered with "green" products and hype -- but without many reliable guideposts for what's effective.

Major corporations including Marriott International Inc. and Hilton Hotels Corp. are studying options as they make decisions on far-reaching environmental initiatives intended to appeal to consumers with a conscience -- and at the same time save on water, energy and waste, without downgrading the quality of service.

"We're currently in what you might call a discovery phase," says Kendra Walker, vice president of brand communications for Hilton. "We're looking at best practices. We're looking at energy-saving light bulbs, water-saving features."

One problem is that there isn't any single standard in the U.S. for what makes a hotel green. Nevertheless, a myriad of products, organizations and consultants are offering their services or stamps of approval to hotels.

"This is uncharted territory for us," says Steve Samson, vice president of rooms operations for Marriott International. "You go on the Web and you see hotels are selling green hotel rooms. But what does that really mean? What is it? That's what we're trying to figure out."

Marriott, which this year established an internal "green council" led by two executives, is examining its suppliers and supply chain -- looking at everything from the kind of toilet paper they buy to how far towels travel from cotton field to factory to hotel, which determines how much of a carbon footprint they leave. Marriott is also asking its suppliers to demonstrate how they save energy, or use recycled products -- in essence, to prove they are green. Vendors are scrambling to make their case to Marriott or risk being dropped.

But confirming the alleged benefits of green products and methods is tricky, Mr. Samson says. "It seems like once you make a decision about something, someone comes back to you and says, 'Yeah, it's okay on that end but it's not so great in this other way,'" he says, adding that Marriott is considering hiring a third-party consultant with environmental expertise.

Sensing strong interest and much confusion from the hotel sector, the Hotel Developers Conference, a professional organization that hosts an annual industry meeting, plans a conference on environmentally friendly hotels in March.

Some hotels have turned to established programs in their efforts to go green. Marriott, for example, in 2001 joined the U.S. Environmental Protection Agency's Energy Star program, which has given it public recognition for using lower-energy flourescent lighting and reducing greenhouse-gas emissions. Marriott touts its accomplishments on its Web site under the heading "Green Marriott."

A handful of hotels have gotten certification from the U.S. Green Building Council, a non-profit group in Washington that grades commercial buildings on areas such as water efficiency, energy use, building materials and indoor air quality. Among them are a Hilton in Vancouver, Wash., and a Marriott at the University of Maryland. But the standards aren't designed specifically for hotels, and retrofitting older hotels to qualify can be prohibitively expensive.

Among other options, Starwood is considering getting certification for its first Element hotel, scheduled to open next July in Lexington, Mass. Depending on what's decided, green measures could add 2% to 4% to the planned $16 millon budget for the hotel, Mr. Lakas estimates.

Green Seal, another non-profit organization in Washington, has an extensive certification program for hotels and motels. The evaluation takes up to three months and costs from $1,950 to $3,000 annually, depending on the size of the hotel. Only 43 hotels nationwide have the certification. The group says interest is picking up, and it is hoping to have another 20 hotels in Chicago certified by this fall.

The "Green" Hotels Association, a Houston-based professional group that charges hotels $100-$750 a year to join, offers a list of approved vendors for products including water-saving toilets and chlorine alternatives. But they aren't vetted beyond a requirement that they send company literature explaining how the product is green. "We take their word for it," says Patty Griffin, president and founder of the association, which has also since 1993 sold a cards to hotels that nudge guests to reuse towels.

But many lodging operators in the group report mixed results in their efforts to go green, even though customers like it.

"There are so many companies promoting 'green products,' the challenge is doing enough research to identify which products are truly green," says Dean Crane, vice president of engineering for Aramark Harrison Lodging, with properties in settings from Lake Powell in Arizona to Glacier Bay National Park in Alaska. "There are many cleaning products that just don't hold up or achieve what they are marketed for."