Perspectives on safety of quaternary ammonium compounds (QACs)

Quaternary ammonium compounds (QACs) are widely used to kill pathogenic microbes (including COVID-19), providing a substantial public health benefit. This review is an update to our previous publications that summarized and interpreted the current knowledge of the safety of the two most widely used QACs, alkyl dimethyl benzyl ammonium chloride (ADBAC) and didecyl dimethyl ammonium chloride (DDAC). A literature search was conducted for studies published since 2000 that addressed possible toxicity of ADBAC and DDAC as well as investigations into human exposure. The current database of high-quality animal toxicology studies with ADBAC/DDAC showed that adverse cellular changes are limited to effects at the point of contact. (1) Non-guideline animal toxicology investigations, (2) studies of the effect of QACs on subcellular functions, and (3) the sole report of systemic effects in humans might not be informative for human health risk assessment. Because of their widespread use, human exposure to QACs is frequent. Various reports measured QACs in media in the home and workplaces. Risk calculations performed based upon these exposure estimates performed as part of this review demonstrated that none of the exposure scenarios examined are predicted to pose adverse health risks to exposed individuals.