By Alison McCook

Clean towels are clean, right?

Several years ago, a group of investigators set out to answer that question. They collected three cleaned towels from 10 Arizona hospitals, submerging each towel in buffered peptone water to extract microbes. They wrung out each towel, collected the broth and examined it for signs of potentially dangerous microbes.

The investigators found them.

More than 90% of the towels contained viable microbes, including 3% with the potentially dangerous bacteria Escherichia coli. Furthermore, more than half of the buckets used to soak towels in disinfectants—the very containers designed to clean the towels—harbored viable bacteria, including those that form spores (Am J Infect Control 2013;41[10]:912-915).


The results are among a body of research that points to a troubling trend: The products used to clean medical facilities may be contributing to their contamination. Now, researchers are asking themselves how to do a better job of cleaning hospital cleaning products.


In the 2013 study, the researchers examined reusable cloths made of cotton and of microfiber, common materials used in cleaning products. Both were contaminated. Roughly 10 years ago, microfibers came onto the market, promising to do a better job of picking up soil and weighing less than cotton, the typical material of cleaning products such as mops and rags (Am J Infect Control 2007;35[9]:569-573).


Since then, hospitals rapidly added them to their roster of cleaning products. But then they came across a dilemma: The laundry techniques that kill microbes—bleach and hot water—also destroy the delicate microfibers. The gentle cleaning process that microfibers need doesn’t always destroy the contamination on the surface of used cleaning products. Now that the world is dealing with an ongoing COVID-19 pandemic, adopting the best products and practices for cleaning has become even more crucial.

The situation has left facilities scrambling for solutions. “We’re finding lots of contamination in the very tools we are using to clean,” said K. Mark Wiencek, PhD, the lead microbiologist at Contec, Inc., a company headquartered in Spartanburg, S.C., that manufactures cleaning supplies. “As a result, we are faced with this conundrum of how to properly decontaminate these towels and mops without destroying the textile.”

A Fine Mess

A microfiber mop that’s been used to clean a hospital floor is, simply put, pretty gross.


“We’re cleaning up after people, and people leave behind a lot of stuff—everything from small bits of human skin and hair to bacteria, fungi and viruses,” Dr. Wiencek said. He and his colleagues have repeated the 2013 experiment, testing mops and towels from hospitals after laundering. “In some cases, the contamination level was too high to count with the traditional and molecular methods we were using,” he said.

Microfiber initially works better than cotton, but after multiple washes and if laundered improperly microfiber may not perform as well (Am J Infect Control 2010;38[4]:289-292), noted Karen deKay, MSN, RN, CNOR, CIC, a perioperative practice specialist at the Association of periOperative Registered Nurses.

Most facilities likely use a variety of materials to clean between patients, she said. In the perioperative environment, for instance, most places employ single-use disinfectant cloths made of polyester to clean and disinfect the surfaces after each patient. At the end of the day, a facility will do a “complete clean” using disposable cotton or microfiber cloths, Ms. deKay said. The mops, too, could consist of cotton mop heads, or reusable and/or single-use microfiber.


Dr. Wiencek agreed that most hospitals still use laundered products, but more facilities are adding disposable products to their supply closet. The use of disposable cleaning products “has really exploded in the last five years,” he said.

Unfortunately, some evidence indicates that contamination of cleaning products is causing infections. More than a decade ago, researchers in Japan linked five cases of infection by spore-forming Bacillus cereus bacteria to reused towels that had been dried and steamed (J Hosp Infect 2008;69[4]:361-367). In 2015, six immunosuppressed patients developed infections from a spore-forming mold, Rhizopus microsporus, by inhaling and touching contaminated linens supplied by a designated laundry (Clin Infect Dis 2016;62[6]:714-721).

A 2015 literature review uncovered 12 outbreaks of infectious diseases associated with laundered health care textiles over the previous four decades (Infect Control Hosp Epidemiol 2015;36[9]:1073-1088). These reports might only scratch the surface, according to Ms. deKay, who said other cases of infections related to laundered cleaning products likely haven’t been documented.


Let’s Clean It Up

However, switching back to all-cotton towels and mops is not a solution, Dr. Wiencek said. As a natural fiber, cotton can biodegrade; that’s good for the environment, but not for the sterile hospital room, where fibers break apart and cause lint.

Some facilities also may want to consider including more disposable products with their cleaning materials, Dr. Wiencek said. Cost could become an issue, as facilities would have to replace each mop pad after every use. But single-use pads are lighter and less expensive than reusable pads, which may not be effective after hundreds of washes. Plus “laundry isn’t free,” he added. “Cost is part of the story, but organizations have to look into their laundry contract to figure out how much they’re paying per use of the product.”

So how can facilities clean microfiber materials properly? The best advice, Ms. deKay said, is to follow the manufacturer’s instructions. Even if the instructions eschew bleach and high heat, the laundry industry’s bug-killers of choice, “instructions from the manufacturers have been validated to show they will get rid of organisms,” she said. Another tip: Separate microfiber cloths from mops because contamination can spread from one to the other.

For now, no additional technology exists that can replace the physical action of rubbing a surface with a chemical disinfectant, but some facilities may want to consider adjunct technologies, Ms. deKay said. Among those, ultraviolet radiation and hydrogen peroxide mist can kill microorganisms and add another layer of protection, she said. However, they can be expensive and can’t do the job alone. “You can’t just use that technology without doing the cleaning, which is why it’s so important that we’re getting the cleaning materials clean.”

Contec, Inc., sells disposable microfibers and other textiles.