What it means. Greenwashing applies to companies that describe themselves or their products as environmentally friendly when they're really not. Greenflushing is the term to use when it comes to toilets: Manufacturers tout the water efficiency of their commodes, but for some toilets to work effectively, you might actually have to flush twice, using much more water than the toilet maker intended.

Why the buzz? The Energy Policy Act of 1992 reduced the maximum flush volume for residential toilets from 3.5 gallons per flush (gpf) to 1.6 gpf. In 2007, the U.S. Environmental Protection Agency's WaterSense program established a standard of 1.28 gpf for high-efficiency toilets. Models that meet this threshold in third-party testing carry the WaterSense label, similar to Energy Star qualification for appliances, lighting, and electronics.

Today, companies are touting the water efficiency of their toilets. For instance, the manufacturer of one model we're testing for our August 2009 report on toilets claims the commode will use up to 6,000 gallons less water each year than a 1.6-gpf model. And some manufacturers are marketing the water-saving potential of dual-flush models, which are designed to use 0.8 or 1.1 gpf for liquid waste and 1.6 gpf for solid waste. But as we've found, companies might be engaging in a bit of greenflushing.

In our liquid- and solid-waste tests, some dual-flush models have had difficulty flushing effectively. In the real world, that means you might have to flush twice and that these toilets consume more water than they should. The claimed savings have, literally, gone down the drain.

Note that many of the single-flush toilets we're testing have been excellent or very good at removing solid and liquid waste alike, with a few doing the job using 1.28 gpf, and one using 1.1 gpf.—Daniel DiClerico | e-mail | Twitter

Essential information: Look for the full report on toilets in the August 2009 issue of Consumer Reports, online and on newsstands in July. In the meantime, see our buying guide on toilets.