A study completed late last year by the NAHB Research Center has caused quite a stir in the toilet manufacturing industry.

Two public utilities groups, Seattle Public Utilities and the East Bay Municipal Utility District (Oakland, Calif.), commissioned the study. NAHB researchers tested 49 different models of 1.6-gpf fixtures by loading them with paper wads, as well as floating and sinking sponges. Researchers then calculated a "flush performance index" for each model, with a lower number indicating better performance. Full results of the testing -- in which three Toto units had the lowest indexes -- were posted on the Research Center's Web site in late October. However, within days, they were removed.

According to an article that appeared in January in the Washington Post, many believed that the Center was pressured to remove the results by toilet manufacturers whose models did not perform well. However, the article reported that spokespeople for the Center and American Standard -- which makes the two toilets who earned the worst flush performance indexes during the testing -- denied that the removal was political. Rather, says Bob Hill, director of lab services for the Center, the study was pulled from the site because the results were being used in ways that were not intended.

"People were putting too fine of a point on it," Hill says. "The sponsors wanted to help consumers make purchasing choices -- to show which toilets work well and which don't." Hill went on to explain that because of variability in the testing and the relative closeness of many of the scores, a clear "winner" could not be declared based on the results. In other words, the Toto Ultramax and Toto Ultimate Elongated Bowl -- which both had a flush performance index of 0.0 -- are not necessarily the best models available, just part of a group of toilets that performed very well.

In January, an abridged version of the results were posted on the Center's sister site, toolbase.org. The shortened report provides a graph showing that over 70% of the toilets tested had flush performance indexes of 10 or less, accompanied by a list of those models. Center spokeswoman Lisa Gibson says that she hasn't heard any more about the controversy since the new report was posted.

To access the abbreviated version of the study, go to toolbase.org and search for "water closet." The original, full report can be found at www.savingwater.org/toilettest.htm.