What is quat binding in disinfectants?
Quaternary ammonium chloride, or quat, is an active ingredient found in many disinfectants. When disinfectants are used at the correct dilution, quats are effective against bacteria and viruses. However, if quat binding occurs, quats can become very ineffective. Quat binding is when the quat becomes attracted and absorbed into fabrics such as cotton, nonwoven towels and other natural textiles. This is because quats are positively charged ions and natural textiles are negatively charged. Quat binding is a phenomenon can reduce the quat level by 50 percent before the disinfectant is applied to the surface. Not only does this reduce the ppm of the quat, it also makes the disinfectant noncompliant with FDA manufacture usage instructions.
There are three common ways to apply a disinfectant to a surface.
- Spray and wipe – this method eliminates quat binding because the disinfectant is directly applied to the surface without the need for a towel. The downsides to this method are that not all surfaces will receive contact, there is a possibility of over spray and inhalation, and the reduction of disinfectant contact time.
- Dip and wipe – a cloth is dipped in the disinfectant for a few seconds and then used. This method can reduce the quat activity in both the disinfectant and the cloth.
- Soak and wipe – a cloth is soaked in the disinfectant for at least 10 minutes before use. This method, like the dip and wipe, can also reduce the quat activity in both the disinfectant and the cloth.
To determine whether quat binding is occurring, a quat strip can be used to test the quat activity. First, test the disinfectant itself at its correct dilution. Next, add a cloth to the disinfectant, and after five minutes, remove the cloth and retest the solution. The quat should remain at the same level if quat binding is not occurring. Distributors should be able to offer quat strips to their customers and when testing the quat activity, be sure to follow the quat testing procedures.
A way to prevent or reduce quat binding is to recognize what types of cleaning tools cause it. Cotton, nonwoven towels and other natural textiles can reduce the quat level due to its properties. Microfiber or micro denier textiles also reduce quat level, however, is insignificant and should be used over natural textiles. Disposable wipes, such as the Century Q Wipes, can also be used. Disposable wipes are designed to have enough quat concentration to compensate for quat binding and they also meet EPA requirements as well.
For a listing of Multi-Clean liquid disinfectants or disinfecting wipes, please visit Multi-Clean’s Disinfectant Products webpage.