Microbiologists have discovered that the liquid soap in some public restrooms is so contaminated that it leaves your hands dirtier than before you washed them, according to a Cleveland Plain Dealer report.
The study — conducted by University of Arizona researchers and GOJO Industries, makers of the Purell hand sanitizer — tested more than 500 samples from refillable soap dispensers that GOJO collected from public restrooms in five cities: Atlanta, Boston, Dallas, Los Angeles, and Columbus, Ohio.
The findings, originally reported in 2011 in the Journal of Environmental Health, indicated coliform and fecal bacteria were thriving in the soapy environment of many containers.
"It was disgusting," said lead researcher Charles P. Gerba, professor of microbiology in the University of Arizona's Department of Soil, Water and Environmental Science Gerba, the newspaper said. "We didn't find any new life forms, but we found plenty of coliform bacteria. I never dreamed there could be so many bacteria in soap."
The researchers said the containers become contaminated when airborne particles land in an open soap container or when a worker refilling the dispensers doesn't properly wash up after cleaning the toilets. Commercial soaps contain preservatives that inhibit the growth of microbes, but they may break down over time.
A better option, researchers said: Use sealed disposal soap containers.