Tips to Prevent Quaternary Absorption and the Dangers of Quaternary Binding

This article discusses ammonium chloride (quaternary) cleaners, how it works, and the serious issue of quat binding that is associated with using these types of cleaners.

What are Quaternary Disinfectant Cleaners?

Quaternary ammonium chloride (quat) is an active ingredient found in many disinfectants and disinfectant cleaning products. Quat disinfectant cleaners are popular because of their effectiveness against germs, bacteria and viruses; their relatively low toxicity at proper dilution; low odors and long shelf life.

What is Quat Binding?

When used properly, quat disinfectants can be very effective. But, if used incorrectly, quat binding can occur, drastically reducing its cleaning efficacy. Quat binding, also known as quat absorption, is a relatively new and misunderstood issue in the janitorial/sanitation industry. Because of its potential to negatively impact cleaning results, it’s starting to garner more attention.

The phenomenon of quat binding occurs when the active ingredient (quaternary ammonium chloride) becomes attracted to and absorbs into fabrics and other porous surfaces, substantially reducing its effectiveness.

The Science Behind Quat Binding

Quats are positively charged ions and cotton and other natural textiles are negatively charged; positive attracts negative. This results in a portion of the quat, not ending up on the surface it is supposed to be cleaning.

Study Shows Quat Levels Deceased by 50 Percent After Just 10 Minutes

One study found the quat level of a disinfectant remaining on a cotton cloth placed in a solution-filled pail was decreased by 50 percent after soaking for just 10 minutes. The solution that is applied to the surface would contain only half of the parts per million (ppm) listed on the label.

Infection Prevention Expert and Medical Facility Directors are Concerned

“As soon as this phenomenon occurs, the quat disinfectant is off label and in violation of federal law,” says J. Darrel Hicks, BA, REH, CHESP, certified expert trainer and author of Infection Prevention for Dummies. “The worst part is that the disinfectant isn’t killing pathogens as it should and, in fact, may be producing microorganisms that are resistant to the disinfectant.”

Hicks estimates that less than one-quarter of environmental services executives are aware of this problem. Even worse, some know about quat binding, and choose to ignore it. “Unfortunately, many people look at the solution to dealing with quat binding as being too costly or unimportant,” says John Scherberger, BS, CHESP, REH, principal at Healthcare Risk Mitigation in Spartanburg, South Carolina. “Failure to recognize the importance of the negative effects of quat binding is careless and shows indifference to the health of their staff and building occupants.”

Jonathan Cooper, director of environmental and linen services at Health Central Hospital in Ocoee, Florida, only recently heard of quat binding after a vendor brought it to his attention. Like many in his position, he’s eager to learn more about preventing the problem.“We spend a lot of money on cleaning supplies, so to render it ineffective is both a waste of money and an infection control issue,” says Cooper. “You think you’re cleaning and disinfecting, but you’re not really removing the bacteria you need to from the surface.”

Using Different Quat Application Methods

To reduce the threat of quat binding, custodial executives must train staff on the pros and cons of various disinfecting techniques. There are generally three ways to apply disinfectants to surfaces:

Spray and Wipe Method

Directly applying disinfectant to the surface eliminates the potential of quat binding. Unfortunately, there are several downsides to this method, including difficulty covering hard-to-reach areas, overspray and inhalation of the chemical.

Dip and Wipe Method

A dry cloth is dipped into a disinfectant liquid solution for a few seconds and the excess solution is wrung out. While it can initially reduce the problem of quat binding, absorption can still occur over the time that the same cloth or mop is used.

Soak and Wipe Method

A common approach for disinfecting is to soak cloths in the quat solution for 10 minutes (or for many hours) before use. The biggest concern about this approach is the cloth has time to absorb quat from the entire bucket of solution.

Quat Binding is Not Visible to the Naked Eye

No matter what method is used for applying disinfectants, there are no visible signs to look for in hopes of avoiding absorption problems.

“Therein lies the problem. The person using the disinfectant has no idea when it becomes ineffective, so they go along their merry way in blissful ignorance, while people continue to get sick because the solution was ineffective,” says Scherberger.

Use Quat Test Strips to Check for Quat Effectiveness

“The disinfectant should be tested, first with no cloths, mops or rags present,” says Hicks. “If the test strip verifies the solution has the available ppm matching the product label, that is good.”

“Once the solutions passes muster, add mops, cloths, or rags to the verified chemical and retest in five minutes. If the test strip now reveals that the solution is no longer within the label’s ppm, the quat is off label and useless as a disinfectant.”, Hicks says.

Consider Switching to Microfiber Mops and Microfiber Cleaning Tools

Another important step in preventing quat binding is to evaluate your cleaning tools. “Quats and cotton simply don’t mix, so it’s important to rid custodial closets of one or the other.”, Hicks says. Rather than using cotton mops, terrycloth towels or t-shirt type rags for cleaning, use microfiber or micro denier textiles with quat cleaners. “There is a small amount of quat binding with microfiber, but the amount is so insignificant it is a non-issue,” says Scherberger.

Although Health Central Hospital’s Cooper isn’t well versed in quat binding, he switched his team to microfiber quite some time ago. “Our tests have shown that microfiber is a better cleaning tool for the removal of surface dirt,” he says. “Cotton just moves dirt around. Microfiber really grabs and holds on to any bacteria and removes it from the surface.” Cooper is not only happy with the performance of the microfiber, he’s happy his decision to use the textile improves the efficacy of his chemicals.

Some manufacturers offer wipes made of textiles that are less likely to absorb quats. Others offer quat disinfectants at concentrations sufficient to compensate for quat absorption. These products are diluted at such a level that even after textiles have absorbed the quat, there is still a sufficient concentration of the chemical to meet Environmental Protection Agency regulations for disinfectants.

Because of their cost and effectiveness, quat-based chemicals aren’t going away anytime soon, which means, quat binding will continue to be an issue. With the focus on disinfection so high, managers should guarantee proper disinfecting by taking a second look at chemical dilutions, textiles and application methods.

Issue of Quat Binding is Critical in Foodservice Industry

While there has been a spotlight placed on the problem in healthcare, quat binding in foodservice remains center stage. “Fifty percent of the foodservice industry uses cotton rental towels or bar towels,” says Tara Millar, product manager at ITW Pro Brands in Olathe, Kansas. “Some larger chains know about the quat depletion issue, but most are still in the dark.”

“Awareness of quat binding needs to grow.”, she adds. “Foodservice facility operators should care about this issue because one out of every six people gets sick from eating contaminated food, and 3,000 people die each year from foodborne illnesses,” says Millar. “It could cost a facility $75,000, or more per outbreak. Plus, they are throwing money out the window on chemicals that are not being used properly.”

pH Testing and Quat Testing are Two Totally Different Things

While there are government regulations that require pH testing of chemicals in the foodservice industry, it has no real impact on quat binding.

“Testing the pH of chemicals and testing the available ppm of active ingredients in a quat are two totally different animals,” Millar says. “The tests are for two different qualities.” Workers in restaurants, cafeterias, or break rooms should follow the same policies and procedures to avoid quat binding as they use in other areas of the facility.

Choosing non-quat products or switching to microfiber or micro denier textiles is critical. “There is an education curve, and there needs to be a thought shift on how to sanitize effectively and properly,” says Millar.

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