Bulk Soap Dispensers: Examining The Potential For Bacterial Contamination

Cleaning budgets are shrinking and anywhere facility managers can save money, they will. Customers are interested in lower-priced product alternatives, especially for consumables such as soap.

Bulk soap dispensers are a cheaper option than sealed systems, and for this reason remain very popular. In fact, many newly constructed facilities are installing bulk dispensers over bag-in-box or cartridge models in an effort to put cost before aesthetics. And now that popular foam soap is available in bulk refills, interest in bulk dispensers will continue to increase.

If building service contractors service facilities with bulk soap dispensers they should be aware that these models have the potential for cross-contamination if not maintained properly.

The facts

Dr. Charles Gerba, aka “Dr. Germ,” an environmental microbiologist at the University of Arizona, sampled bulk soap from 541 dispensers in five cities across the United States. The study, published in the March 2011 issue of the “Journal of Environmental Health,” found that 24.8 percent of the samples contained significant levels of bacteria, including coliform bacteria, found in 15.9 percent of samples.

Office restrooms were the leading breeding grounds, followed by gyms/health clubs, restaurants and retail stores.

Most soaps are produced with a preservative to inhibit microbes, but it degrades with time, says Dr. Gerba. Bulk soap is frequently shipped as a concentrate to end users and diluted in a 20-gallon drum.

“There’s biofilm in the cracks and crannies, and it just regrows every time,” says Dr. Gerba.

Bulk soap can also become contaminated by dust in the air, toilet water pluming out of commodes and urinals, or by janitors’ hands.

Most soaps, even those not advertised as antibacterial, contain preservatives to ward off contamination, says Benjamin Tanner, president of Antimicrobial Test Laboratories in Austin, Texas. However, once bacteria are present, they can quickly overwhelm the preservative. All bacteria needs to grow is a little water, such as condensation in the container or a splash from the sink, he says.

If soap is contaminated, it will leave bacteria on users’ hands, which will then be transferred to any other objects they touch.

“You can have more bacteria on your hands after you wash than after flushing the toilet,” says Dr. Gerba.

Although 500 colony-forming units per milliliter is considered a benchmark, Dr. Gerba says that most of the samples are “usually in the millions, or hardly anything.”

The U.S. Centers for Disease Control and Prevention advise against topping off soap containers in a guideline for health-care settings. Recent Canadian regulations require a “Do not refill container” label on bulk dispensers in food-handling situations, says Brian Sansoni, vice president of communication for the American Cleaning Institute.

Read more about preventing cross-contamination in soap dispensers here. 

David Lewellen is a freelance writer based in Glendale, Wis.