Reliable household products get the Good Housekeeping Seal. Safe electronics earn Underwriters Laboratories’ UL mark.

But consumers and investors looking for environmentally responsible products and services have to trudge through a swamp of seals, claims and certifications — only some of which designate independent, verified environmental accomplishments.

There’s “Green Seal,” founded by Green Seal Inc., and “Co-op America Seal of Approval,” which deems products “Approved for People and the Planet,” started by a group of the same name.

Product manufacturers and retailers further muddy the water by adding more general titles and symbols, including “Certified Green,” “Green Certified,” just plain “Green” — and more “Green Business” logos than you can shake a tree at.

Wood and paper products might be marked with the Sustainable Forestry Initiative seal or the Forest Stewardship Council shield; some products sport both.

And then there are the more general claims, including “nontoxic,” and even just plain “green.”

“I’d like to say that if there’s no credibility behind it, a label won’t survive, but that’s not necessarily true,” said Linda Chipperfield, the vice president of marketing and outreach for Green Seal Inc., an independent nonprofit.

Julie Collins, a 24-year-old editor and writer for TheHomeKnowItAll.com who blogs about environmentally responsible cleaning products, said she stays away from products with only vague promises such as “natural.” And, particularly with household cleaners, she said she tries to steer clear of anything without a precise ingredient list.

But those efforts still don’t guarantee that the products she’s buying actually are safe for the environment, Collins said. And that doesn’t even take into account questions such as product packaging, manufacturing processes and the greenhouse gases emitted to ship the product to the store, she said.

“All kinds of products are cropping up and it’s hard to tell which ones are actually making solid claims and which ones are throwing ‘natural’ on the label or some similar term,” said Collins, who lives in Des Moines, Iowa. “The most frustrating thing is when you spend more money on something that you think is green or environmentally friendly and then when you get home you realize that it’s pretty similar to all the other items. I still get duped.”

Label confusion isn’t restricted to products claiming to be green — there are tussles over the precise meaning of “organic,” “pesticide free” and other terms.

Most would-be eco-products, however, are one step closer to the Wild West of marketing because no federal agency offers a universal seal, leaving a wide berth for vague language.

“What is sustainable? What is considered to be green electricity?” asked Bruce Hamilton, the deputy executive director of the Sierra Club. “People are consciously trying to fuzzy the boundary lines between clarity and lack of clarity so they can sell more products. Everybody is trying to promote their products as green even though they may not be.”

Even leaving aside products that make outright false claims, consumers have to weigh competing seals from organizations with different standards.

The Forest Stewardship Council, whose seal looks like the outline of a fluffy tree above the letters FSC, certifies wood and wood products harvested or made from forests it recognizes as sustainable and well managed.

Founded in 1993 by activist and industry groups, the group says it is “the only global forest management certification system where social, environmental and industry interests carry the same weight.” Its board of directors includes the chair of Greenpeace and the vice-chair of the National Wildlife Federation.

The Sustainable Forestry Initiative seems to offer a similar certification. Its seal says “SFI Certified Sourcing,” along with an outlined pine tree inside a leaf. That group maintains that its program “is based on the premise that responsible environmental behavior and sound business decisions can coexist.”

But although the group defines itself as a fully independent organization composed of environmentalists, forestry industry officials, academics and public officials, many activists assail the group as misleading and beholden to industry — going back to its beginnings as a project of the American Forest and Paper Association.

Its board includes the chairman of International Paper Co. and the chairman of Plum Creek Timber Co., as well as the president of the American Bird Conservancy and the president of Wildlife Management Institute.

The Consumers Union Guide to Environmental Labels says that neither group is free from conflict of interest. But it maintains that the Sustainable Forestry Initiative also has problems with inconsistent labeling, standards that weren’t developed with broad public input and criteria that allow “prudent” use of chemicals and forest clear cutting of anything less than 120 acres.

“We need to have scrutiny on these labels, but we can’t lose sight of the companies that have taken this on to seek third-party certification, regardless of the standard chosen,” said SFI’s new president, Kathy Abusow.

Consumers Union also criticizes the Forest Stewardship Council, the seal favored by many environmentalists, for lowering some standards for paper since the group was founded and for allowing forest clear cutting of 200 acres or less.

The head of Consumer Reports’ eco-labels.com Web site said she wouldn’t want to see a single unifying label or seal, because it would be too difficult for any one group to certify the environmental soundness of every product, service and business. But, she added that a good system wouldn’t be as confusing as it is now.

“It’s a morass out there to some degree,” said Urvashi Rangan, who also is a senior scientist and policy analyst for the consumer group. “I feel sorry for consumers, and I guess that’s why we put this thing out in the first place.”