Antimicrobial Science News: January 2026
By Rebecca Fuoco | January 13, 2026
More and more studies are being published on the harms—and often, lack of benefit—of antimicrobials but are flying under the radar. Monthly, we will be sharing notable new peer-reviewed research related to quaternary ammonium compounds (QACs) and other antimicrobials used in consumer products. Below are studies published over the last month.
- Findings from experiments in rats suggest that repeated inhalation exposure to benzalkonium chloride can damage the heart and pancreas at occupationally relevant doses. (Dong-A University)
- Benzalkonium chloride induced dose-dependent sensory neurotoxicity in zebrafish. The authors found that the chemical compromises sensory system integrity through intertwined oxidative, inflammatory, and neurotoxic mechanisms. “These results underscore the broader neurodevelopmental and ecological hazards of quaternary ammonium compounds,” the authors conclude. (Korea University)
- A common group of QACs called dialkyldimethylammonium compounds inhibited a human and rat enzyme critical in brain neurosteroid synthesis, suggesting “potential risks to brain health.” (Wenzhou Medical University)
- Environmentally relevant concentrations of chloroxylenol impaired tadpole gut health, disrupting normal amphibian development. (Shaanxi Normal University)
- A systematic review found that frequent or prolonged use of antiseptic mouthwashes, especially containing chlorhexidine, can foster resistance traits in oral bacteria. (Aligarh Muslim University)
- While wastewater treatment plants are effective at removing QACs, a large fraction of the mass in influents is sorbed to biosolids, leading to potential release to the environment. The authors calculated that 1900 tons of QACs enter U.S. wastewater treatment plants in liquid influents annually, while 30 tons are discharged with liquid effluents and 770 tons leave with biosolids (of which 640 tons are land applied or landfilled). (University of Minnesota)
- A persistent biodegradation product of benzalkonium chloride was identified as a potent precursor of the carcinogen N-nitrosodimethylamine in natural and treated waters. The authors note that in addition to incomplete biodegradation of benzalkonium chlorides during wastewater treatment, widespread use of disinfectants may introduce these precursors into surface waters. (National Sun Yat-sen University)
- Benzalkonium chloride and methylisothiazolinone are the most common biocides used for biofilm control in industrial water systems. However, a new study found they are ineffective against biofilm-associated free-living amoeba, even at high concentrations. (Flinders University)
- A case series of eight patients found that the use of benzalkonium chloride-containing laundry sanitizer induced granular parakeratosis (a skin condition characterized by scaly eruptions). The authors say that children are most susceptible. (Wenzhou Medical University)