Exposure to common quaternary ammonium disinfectants decreases fertility in mice

• Tested the reproductive toxicity of a common disinfectant used in many commercial and residential products.
• Disinfectant contained the active ingredients: alkyl dimethyl benzyl ammonium chloride (ADBAC) and didecyl dimethyl ammonium chloride (DDAC).
• Mouse breeding pairs were dosed with ADBAC + DDAC at 0, 60 or 120 mg/kg/day in the feed for 6 months.
• Long term exposure decreased fertility and fecundity and caused dam mortality in a dose dependent manner.
• This study highlights the importance of testing the toxicity of mixtures over individual compounds.

Quaternary ammonium compounds (QACs) are antimicrobial disinfectants commonly used in commercial and household settings. Extensive use of QACs results in ubiquitous human exposure, yet reproductive toxicity has not been evaluated. Decreased reproductive performance in laboratory mice coincided with the introduction of a disinfectant containing both alkyl dimethyl benzyl ammonium chloride (ADBAC) and didecyl dimethyl ammonium chloride (DDAC). QACs were detected in caging material over a period of several months following cessation of disinfectant use. Breeding pairs exposed for six months to a QAC disinfectant exhibited decreases in fertility and fecundity: increased time to first litter, longer pregnancy intervals, fewer pups per litter and fewer pregnancies. Significant morbidity in near term dams was also observed. In summary, exposure to a common QAC disinfectant mixture significantly impaired reproductive health in mice. This study illustrates the importance of assessing mixture toxicity of commonly used products whose components have only been evaluated individually.