Antimicrobial Science News: April 2026

By Rebecca Fuoco | April 14, 2026

More and more studies are being published on the harms—and often, lack of benefit—of antimicrobials but are flying under the radar. In these newsletters we will be sharing notable new peer-reviewed research related to quaternary ammonium compounds (QACs) and other antimicrobials used in consumer products. In the past month, there have been studies published finding links to reproductive, respiratory, cardiovascular, neurological, and skin harms as well as antimicrobial resistance:

Cardiovascular Harm

A study of elderly humans found links between QACs and electrocardiogram disturbances. “This study provides the first population-based evidence of QAC-associated cardiotoxicity and proposes the underlying biomolecular alternations,” the authors state. (China CDC).

Reproductive Harm

A study in pigs found that benzalkonium chloride impairs oocyte maturation and developmental potential. “Given the increasing detection of BACs in human and environmental samples since the COVID-19 pandemic, our findings highlight potential reproductive risks associated with chronic low-dose exposure,” the authors conclude. (Anhui Agricultural University)
In an in vitro study, benzalkonium chloride inhibited human and rat enzymes found in gonads that are critical for reproductive hormone production. The three potent BAC homologues also suppressed progesterone synthesis in intact human ovarian granulosa tumor cells at very low concentrations. These findings suggest that BAC disinfectants may act as potential endocrine disruptors by interfering with steroidogenesis,” the authors say. (Wenzhou Medical University)

Neurological Harm

A study found that benzalkonium chloride functions as a potent inhibitor of a key human and rat neurosteroidogenic enzyme. "Our results warrant further investigation into the potential neuroendocrine-disrupting effects of chronic and low-level BAC exposure," the authors conclude. (Wenzhou Medical University)

Respiratory Harm

Mice exposed to QACs via inhalation at lung-damaging doses showed blood levels of 1–100 nM, overlapping with the 1–50 nM levels measured in humans — suggesting that everyday human exposure approaches concentrations associated with harm. (UC Davis)

Skin Harm

A case study found that benzalkonium chloride in laundry sanitizer triggered systemic contact dermatitis in a patient previously misdiagnosed with eczema. (Chengdu University)
In a study using a 3D human skin model, shorter-chain QACs passed through skin and absorbed rapidly, particularly when the skin was sweaty. The study also found that QAC exposure disrupts the skin's protective barrier and triggers immune responses. (Southern University of Science and Technology)

Antimicrobial Resistance

A study of public restroom sink drains cleaned daily with quaternary ammonium disinfectants found persistent biofilms dominated by bacteria carrying both qac resistance genes and antibiotic resistance genes. Between 34% and 53% of the qac resistance genes were located on mobile genetic elements, meaning resistance traits can spread between microbes. (Marquette University)
Listeria monocytogenes adapted to benzalkonium chloride grew faster than the wild-type strain in pasteurized milk and pork sausage. "These findings demonstrate that BC adaptation in L. monocytogenes poses significant risks to food safety and human health," the authors conclude. (Xinxiang University)

Lack of Effectiveness

A comprehensive review of Candidozyma (Candida) auris in healthcare environments concluded that “infection control methods including active surveillance, contact precautions, and environmental disinfection with sporicidal agents and avoidance of ineffective quaternary ammonium compounds are key to preventing the nosocomial spread of C. auris” https://pubmed.ncbi.nlm.nih.gov/41821213/