1. What is a Quaternary Ammonium Compound (QAC or quat)?
Quaternary ammonium chloride compounds are a diverse group of substances that share a common molecular structure. They are used in formulations of sanitizing and disinfecting products to kill disease-causing germs on hard, non-porous surfaces.
2. What’s the difference between cleaning, sanitizing, and disinfecting?
Cleaning physically removes germs, dirt, and impurities from surfaces or objects. This does not necessarily kill germs, but by removing them, it lowers their numbers and helps reduce the risk of spreading infection. For most disinfecting products, cleaning must occur before disinfection.
Sanitizing chemically lowers the number of bacteria on surfaces or objects to a safe level. Sanitizers reduce 99.9% of bacteria listed on the product label. These products are not registered to kill viruses. A specialized type of sanitizer registered as a Food Contact Surface Sanitizer kills 99.999% of bacteria in 1 minute.
Disinfecting kills all disease causing germs listed on the product label. Killing germs on a surface (especially high-touch areas) after cleaning further reduces the risk of spreading infection. Disinfectants are widely used in hospitals, schools, offices and homes. Many quat-based disinfectants are “one-step” products, which clean and disinfect in one operation. Product labeling clearly states proper use instructions.
3. Are quats safe to use?
Quats are highly effective sanitizers and disinfectants that have been studied extensively showing they are safe and effective when used as directed. The safety data generated is used by the Environmental Protection Agency and by European Chemicals Agency in the registration process. These registrations are periodically reviewed by both agencies. The studies are rigorous and evaluate possible effects on human health and safety so that appropriate regulatory and use guidelines can be developed.
4. How long have quats been known and used?
The first quats were introduced almost 100 years ago. Quats are highly effective disinfectants used on hard, non-porous surfaces in healthcare facilities, in schools and office buildings and in foodservice and food distribution locations. They are widely used in agricultural settings, as well. Quats are also found in household cleaners, sanitizers and disinfectant products.
5. What disease agents do quat-based disinfectants help to control?
Formulations containing quats kill a wide variety of bacteria, viruses, molds and fungi. Not all products kill all germs, but each product label lists the germs it kills. For this reason reading the label is important. See a complete list of disease-causing germs here that are killed by the many different quat-containing formulations.
6. How do quat-based products kill bacteria and viruses?
Quat molecules are positively charged and attach to and destroy outer membranes on bacteria, literally dissolving the bacteria. Quats kill viruses by binding to their external coats, preventing normal function.
7. Do quats work the same way that antibiotics do?
No. Antibiotics inhibit metabolic pathways in disease-causing bacteria. Quat-based products interact with bacterial cell walls so the bacteria die. Antibiotics are used as medications in humans and animals.
8. Do quat-based products kill all organisms that cause disease?
No, but they are used routinely to kill a broad spectrum of them. Quat-based formulations kill more than 150 different kinds of germs.
9. Do quats affect the environment?
A variety of studies suggest that appropriate wastewater treatment causes the quats in wastewater to bind to sludge, forming compounds that are no longer reactive in the environment. Two recent summaries of peer-reviewed literature provide more details on this.
10. What other environment impact information is available?
Quats are immobile in soil, because they bind to sediment and soil. They do transfer into surface and ground waters. Quats are biodegradable.
11. Do surfaces treated with quats remain organism-free for any period of time after use?
As of 2020, the EPA has begun to approve products that may offer longer-lasting protection on surfaces. These products are primarily used in commercial, not residential, applications. They are being used in the transportation industry (airplanes, buses, trains, subways, etc.) where high touch surfaces can be readily contaminated by passengers. As new products are introduced one can check the product label to confirm if the active ingredient is a quat.
12. How are quats shown on product labels?
They are shown using their scientific names. There is also an EPA-registration number associated with each compound. All claims made on the label about the product’s effectiveness must be reviewed and approved by the EPA. Click here for product label identification information.
13. What is the best way to apply quat-based products?
For all products, read the labels and apply accordingly to instructions. For sanitizing and disinfection, quat-based products are applied to solid, non-porous surfaces.
14. Can pregnant women use quat-based products?
There’s no evidence in safety data used by worldwide regulatory agencies to suggest there is any reproductive toxicity associated with quat-based products. Quats do not cause birth defects or other reproductive issues in rigorous laboratory tests with animals.
15. What are the most common side effects associated with using quat-based disinfectants?
Quats have been produced and used safely since the 1940s. They are eye and skin irritants, particularly as concentrates. These concentrated products are sold only for industrial/commercial use by trained personnel and have specific labeling instructions for their on-site dilution and safe use. Consumer product formulations with quats are ready to use. They are highly diluted and adverse events, when used according to label directions, are rare. Eye and skin irritation have been reported when products are not used correctly. Consumer products have, in general, less than 3/10th of a percent of quat in their formulations.
16. How do quats work to kill germs?
Quats carry a positive charge which is partially responsible for their attraction to bacteria, viruses, and other types of pathogens (germs). Once Quats adhere to the surface they contribute to the death of the microorganism or inactivation of the virus.
17. Why must surfaces be cleaned before using quat-based disinfectants?
Many disinfectants are inactivated by the presence of organic matter such as dirt, dust, food particles and the like on surfaces. Quats in a disinfectant or sanitizer formulation can adhere to this organic matter. To assure thorough disinfection or sanitization, a grossly dirty surface should be cleaned before the surface is sanitized or disinfected.
18. What are the technical names for quats?
Alkyl dimethyl benzyl ammonium chloride (ADBAC) and didecyl dimethyl ammonium chloride (DDAC).
19. Who can I contact if I have technical questions about quats?
20. Are there germs that are resistant to quats?
Proper use of quats can help eliminate a wide range of germs from hard non-porous surfaces when used according to directions. Disinfection protocols in healthcare facilities call for routinely alternating the types of disinfectants that are used to clean hard surfaces to avoid the potential for such resistance to occur. No microbial resistance has been reported against Quat based disinfectants or sanitzers when they are used as directed on the product label.
21. Are the inactive ingredients in quat-based disinfectant products listed by quantity or alphabetically?
The Environmental Protection Agency (EPA) does not require listing inactive ingredients on product labels. All inert ingredients used in EPA-registered products have been reviewed and approved for their use in disinfectant formulations. Some companies that make products with quats in the formulation provide inactive ingredient information on their websites.
22. Are quats used in any “green” cleaning products
EPA regulations for ALL disinfectants do not permit “green” claims to be used on products classified as “pesticides.” Quats fall into that classification because germs are considered to be “pests.” This is the case even when some products might otherwise qualify for this designation.
23. Do “green” products now being promoted for use in schools and elsewhere work as well as quat-based products?
Products that are currently promoted as being ‘green’ are effective only for cleaning unless they carry an EPA registration number. Quats and other disinfectants should still be used to kill bacteria, viruses, molds and fungus on hard surfaces. Ingredients used in some “green” products may actually lead to allergic reactions for some people so care must be taken in selecting green cleaning products or green disinfecting products.
24. Do quats cause asthma?
Asthma is stimulated by inhaling airborne irritants, including plain water sprayed into the air, pet dander, pollen, cigarette smoke, debris associated with cockroaches, fragrances and many other airborne substances. Quats provided as ready-to-use wipes or available in a solution that is mopped or wiped onto a surface do not readily evaporate or become airborne. Quat-based products are also sometimes applied by coarse-spray devices, such as handheld spray or pump containers. These sprays produce large droplets that fall immediately onto the hard surfaces being disinfected. They do not remain airborne and are unlikely to be inhaled.
All aerosol products, regardless of their ingredients, have the potential to affect asthmatics. These product types should be used with care in the presence of sensitive individuals, with appropriate ventilation.
25. Does the EPA classify quats as carcinogenic?
No. The EPA classifies quats as “not likely to be a human carcinogen.”
26. Why are quats registered by the EPA as pesticides?
Disease-causing germs are considered as “pests” by the EPA, so any product that disinfects must be registered by the EPA and regulated as a pesticide. Quats are not in the same classification as agricultural products used to kill insects, which is what most people think of when they see the word “pesticide.”
27. What toxicity categories do quats fall under?
The EPA has three general classifications for products that require special labeling,
CAUTION category. A listing of Cautions are found on product labels. Quat-based products for home use which are ready-to-use typically carry a Caution category.
DANGER is the highest category. Package labels carry “KEEP OUT OF REACH OF CHILDREN” and information on first aid treatment for any route of exposure e.g., in the eyes, on skin, if swallowed or inhaled. Concentrated Quat products used in commercial applications for disinfection and sanitizing can carry a DANGER label.
WARNING labeling is required if the product is fatal if swallowed or absorbed through the skin.
28. Do quat-based disinfectants help protect against Swine Flu / seasonal flu / the common cold / COVID 19 and norovirus?
Disinfectant formulations can be highly effective in eliminating germs on hard, non-porous surfaces that people routinely touch. This helps to reduce the likelihood of disease transmission. Different formulations can eliminate different pathogens. Read the product label to see which germs the product can kill and follow the specific use directions to make sure the product is applied correctly so that it can be effective. The EPA’s “N” list provides the names of products registered to work against COVID 19. The EPA G list names products that work against norovirus, which is one of the most difficult viruses to kill.