Antimicrobial resistance remains a pressing public health concern and a leading cause of death around the world. Treating infections with antibiotics is a decision made by the healthcare provider after carefully considering the benefits and risks of treatment. However, healthcare providers may not think as carefully about the benefit-risk trade-offs when using antimicrobial products liberally to disinfect high traffic surfaces such as door handles and exam tables. Like their pharmaceutical counterparts, antimicrobial disinfectants can also come with "side effects" and may be contributing to the rise of superbugs.
Antimicrobial disinfectants serve a critical public health purpose: to decrease the spread of disease. But, as we know with antibiotics, there is a downside to overusing products. Not only can antimicrobials such as quaternary ammonium compounds (known as QACs or quats) contribute to antimicrobial resistance, the evidence of harm to human health from exposure to QACs is increasing. The COVID-19 pandemic magnified the use of disinfectants and alcohol-based sanitizers in healthcare and non-healthcare settings. On top of overzealous use of wipes, sprays, and cleaning solutions, the pandemic has also boosted the relatively new of putting antimicrobials on nonporous items and in durable goods (pillows, socks, furniture, airplane brochures).
A recent of QACs (co-authored by one of us -- Amina Salamova, PhD, MS), presents evidence of suspected or known adverse health outcomes from human and laboratory animal research. These include dermal and respiratory effects, developmental and reproductive toxicity, and disruption of metabolic function associated with exposure to QACs. In addition, the review demonstrates that concentrations of QACs in the environment are already approaching levels known to be toxic to aquatic organisms and they are now detected in human blood and breast milk.
QACs are produced or imported in the U.S. at greater than per year and their use in products and subsequent concentrations in the environment are increasing. The spread of antimicrobial resistance, exacerbated by QACs, can decrease the effectiveness of disinfectant products and thus, negatively impacts antibiotic stewardship. The medical community has taken steps to reduce overuse of antibiotics, and this approach could serve as a good model for antimicrobial QACs: using them only when effective and necessary. Even better would be to replace them completely with safer products that have similar or greater efficacy to fight evolving microorganisms without leading to antimicrobial resistance.
Government oversight of QAC usage varies widely depending on the agency and the product category. Some products such as pesticides are required to be labeled as containing QACs while many others such as paints are not. Very few of the hundreds of QAC products are regulated or even comprehensively screened for health hazards. Merely searching through the array of product categories that contain QACs will likely lead to fatigue and disappointment as these products are difficult to uncover.
Without a thorough understanding of QAC use and the impact on human health, it is reckless for the U.S. to proceed at the current pace. While more research is needed in some areas, there are preventive steps the medical community can take now. For example, many are effective against SARS-CoV-2 and some alternatives to QACs are effective against a wide range of pathogens responsible for healthcare-acquired infections including Clostridioides difficile spores. Hydrogen peroxide formulations and peracetic acid, for example, have a broader spectrum of antimicrobial activity and a health and environmental hazard profile than QACs for noncritical patient care surfaces and devices.
Already some healthcare facilities, such as Emory Healthcare, have discontinued the use of QACs, opting for hydrogen peroxide-based products instead. Not only do they provide improved effectiveness, they have drastically decreased necessary drying time by over half, reducing the required 10-minute drying time for QACs to an easy 1 minute. Emory hospital employees have reported improved workplace satisfaction and patient care room turnover times have greatly reduced.
To be more informed and a consumer-savvy leader in health, health systems and facilities should follow the for the correct indication, selection, and method when applying disinfectants. Following , institutions can prohibit the purchase of durable goods (e.g., fabrics, furniture, or carpeting) that have embedded antimicrobials including QACs.
The goal is simple: eliminate unnecessary uses of QACs. Replace with safer infection control products, especially in settings where cleaning is frequent and human health is at risk. Preventive action holds the promise of avoiding yet another public health crisis such as with lead exposure or smoking, where harm continues while we debate the details. QAC use should be reduced before our health and that of the ecosystem is irreversibly damaged.
is an assistant professor in the Gangarosa Department of Environmental Health in the Rollins School of Public Health at Emory University in Atlanta. is the corporate director of infection prevention at Emory Healthcare, and a fellow of the Association for Professionals in Infection Control and Epidemiology (APIC). is an assistant professor in the Nell Hodgson Woodruff School of Nursing at Emory University.