Quaternary ammonium compounds (QACs) are antimicrobial disinfectants commonly used in commercial and household settings and everyone is virtually exposed to these chemicals every day. Two common quaternary ammonium compounds, alkyldimethylbenzyl ammonium chloride (ADBAC) and didecyldimethyl ammonium chloride (DDAC), are combined in common cleaners and disinfectants.

In this study introduction of a cleaner containing ADBAC+DDAC in the living chambers caused neural tube defects (NTDs) in mice and rats. They found increased neural tube defects with exposure to the disinfectant combination in both rats and mice. The neural tube defects persisted for two generations after cessation of exposure.

They also found that male exposure alone was sufficient to cause neural tube defects. Equally significant, ambient exposure from disinfectant use in the cage they were kept in, influenced the levels of neural tube defects to a greater extent than oral dosing. So the ambient exposure through the air and surfaces had more impact than the feeding.

These results clearly demonstrate that ADBAC+DDAC in combination are teratogenic (birth defects) to rodents. Given the increased use of these disinfectants, further evaluation of their safety in humans and their contribution to health and disease is essential.

Quaternary ammonium compounds (QACs) are a large class of chemicals used for their antimicrobial and antistatic properties. They are common ingredients in cleaners and disinfectants, hand wipes, food preservatives, swimming pool treatments, laundry products, shampoos, conditioners, eye drops, and other personal care products. QACs have been in use for over 60 years, but the number of products containing QACs has increased recently as the versatility of these compounds is recognized. Over time, the chemical structure has been altered to increase antimicrobial and surfactant efficacy resulting in multiple generations of these products. Many products now contain a combination of two or more QACs. Extensive use of QACs results in ubiquitous human exposure, yet reproductive toxicity has not been evaluated.

Because chemical mixtures can act synergistically to produce greater toxic effects than the sum of the individual components, evaluation of common mixtures is essential in the evaluation of chemical risk.

This study was initiated because some laboratories which breed and test with mice and rats had noticed some anomalies. One laboratory noted abrupt declines in mouse colony productivity, along with declines in fetal health, that coincided with the introduction of disinfectants containing the QACs, alkyl dimethyl benzyl ammonium chloride (ADBAC) and didecyl dimethyl ammonium chloride (DDAC). Several years later, the laboratory encountered breeding problems and neural tube birth defects (NTDs) that began shortly after a change in room disinfectants. These experiences pointed to the QAC disinfectant but could not confirm toxicity because neither incident tested QACs under experimental conditions.

In an earlier study by the same team reproductive studies demonstrated that QACs adversely affect both male and female fertility and fecundity in rodents (Melin et al., 2014, 2016). 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.

Source 1

Ambient and dosed exposure to quaternary ammonium disinfectants causes neural tube defects in rodents. Hrubec TC et al 15 June 2017. http://onlinelibrary.wiley.com/doi/10.1002/bdr2.1064/full

Source 2

Exposure to common quaternary ammonium disinfectants decreases fertility in mice.

Melin VE1, Potineni H1, Hunt P2, Griswold J2, Siems B3, Werre SR4, Hrubec TC5.Reprod Toxicol. 2014 Dec;50:163-70. doi: 10.1016/j.reprotox.2014.07.071. Epub 2014 Aug 14.