Here's something that might send you dashing back to the washroom: Microbiologists have discovered that a quarter of the soap in public restrooms is so contaminated that it leaves your hands filthier than before you washed them.

So, what does this mean if you’re thinking of putting the “trendy” refillable dispensers in your hotel, gym or Airbnb shower?

Well, scientists have known for decades that liquid soap dispensers and other communal consumer products can become contaminated with bacteria, but no one had specifically studied how often and to what extent that happens

“Fact: some of the soap they tested contained so much fecal matter that you're almost better off washing your hands in the toilet after you flush it” - Charles P. Gerba, professor of microbiology in the University of Arizona's Department of Soil, Water and Environmental Science. 

Gerba headed a team of researchers that tested more than 500 soap samples that was collected from public bathroom areas in five cities: Atlanta, Boston, Dallas, Los Angeles, and Columbus, Ohio, as reported in the March 2011 "Journal of Environmental Health."

The samples were taken from refillable soap dispensers in the showers of health clubs and hotels, as well as the bathrooms of offices, restaurants, retail stores, and shipped on ice via overnight mail to the University of Arizona.

Turns out that washing with dirty soap could leave your hands with "25 times more (potentially harmful) gram-negative bacteria after washing than before washing with contaminated soap," Basically put, "You could end up going into a public restroom and coming out dirtier than you were before."

Fig. 1.
Sample images from a controlled study (Table 2) to determine the number of bacteria from contaminated hands transferred to an agar surface before (A and C) and after (B and D) hand washing with soap containing 4.51 log10 CFU/ml (A and B) or 7.51 log10 CFU/ml (C and D) of S. marcescens.

The bacteria found in contaminated dispensers were there in concentrations of about 1,000 times what the industry recommends.

Besides being unsavory, those bacteria are opportunistic microbes that can cause eye infections, skin infections, bladder infections and urinary tract infections. They can also endanger people with compromised immune systems, or those recovering from surgery or major burns, he said.

The Centers for Disease Control and Prevention has clear guidelines about liquid soap for healthcare facilities: "Do not add soap to a partially empty soap dispenser. This practice of 'topping off' dispensers can lead to bacterial contamination of soap." 

Bulk soap dispensers are now rare in hospitals and nursing homes but remain overwhelmingly common in other public restrooms and now hotels.

Can dirty soap dispensers be washed?

Researchers also went out to an elementary school in northern Summit County to figure out if contaminated soap dispensers could be disinfected and reused. It found teachers and students there unknowingly washing their hands from 14 bulk dispensers -- all of which were contaminated to varying degrees.

For this phase, researchers worked with Montana State University's Center for Biofilm Engineering, which specializes in studying the communities of bacteria called biofilms.

Researchers there found that even when you drain the soap out of a dispenser, disinfect it with bleach, and refill it with fresh soap, "within two weeks, the soap inside the dispenser was just as contaminated as before the cleaning.”

That's because the biofilm bacteria that remains on the inside of the dispenser is very resistant to bleach, and even a tiny amount -- especially in the hard-to-reach nozzle -- was enough to re-contaminate the soap. Because shampoo and soap dispensers are usually bolted to the walls, they and can't be washed as vigorously as they are in laboratory experiments.

So, what can you do?

Researchers think it's best to eliminate refillable soap dispensers entirely and replace them with sealed-soap dispensers that squirt soap directly on the hands. In the world of hotels and Airbnb’s, utilizing individual toiletries can be your best bet to combat all that ugly bacteria. Individual bottles are also an excellent marketing tool when customized with a logo that proudly displays your property’s name and that guests can keep as a reminder of their great stay with you. As for keeping things eco friendly; partially used products and bottles, they can be donated and recycled through local nonprofits such as Soap for Hope – Disaster Aid Canada.

Keep Clean and Healthy.

-Team Custom