Health and Environmental Impacts
In Massachusetts, the TURA SAB considers petitions to add or delete chemicals from the TURA chemical list. In reviewing the science about DDAC and ADBAC, the SAB had concerns related to these substances, including respiratory system irritation and inflammation including outcomes consistent with occupational asthma and work-exacerbated asthma; corrosive effects; hazard for aquatic life; and environmental fate and persistence. The SAB had additional concerns for reproductive effects and neural tube development.
QACs are associated with both acute (short-term) and chronic (long-term) health effects. Exposure can occur by inhalation, dermal, and oral routes. QACs pose concerns for people using them for cleaning both in the home and in the workplace. In addition, the residues from treated surfaces, including utensils, countertops, equipment, and appliances, can migrate to food, resulting in ingestion by humans.
The majority of data that regulatory agencies have used to make recommendations on use and health and safety are based on the individual chemical. However, many of these product formulations typically contain several different QAC substances, in addition to other ingredients that may be irritating or sensitizing.
Acute (Short-term) Health Effects
EPA classifies five types of acute exposures (oral, dermal, inhalation, skin and eye irritation) into four Toxicity Categories, Category I being the highest hazard. ADBAC and DDAC are acutely toxic through the oral, dermal, and inhalation exposure routes. EPA classifies both substances in Toxicity Category II for the oral and inhalation route, and Toxicity Category III for the dermal route.
Irritant: Eyes, nose, throat, or lung irritation have all been reported among workers exposed to QACs. For skin and eye irritation EPA has categorized DDAC and ADBAC as Toxicity Category I: Corrosive. According to the European Union’s harmonized classification they are considered irritants and corrosive to the skin and eyes.
Chronic (Long-term) Health Effects
Chronic occupational health hazards associated with using QACs include dermal irritation that may lead to skin sensitization, and an increased risk of asthma.,,, The Association of Occupation and Environmental Clinics (AOEC) lists both DDAC and ADBAC as asthmagens and respiratory sensitizers.,
Respiratory Effects/Asthma: Surveillance studies, case reports, and animal studies indicate that DDAC and ADBAC are associated with respiratory system irritation and inflammation including outcomes consistent with occupational asthma and work-exacerbated asthma. Recent studies have suggested that occupational exposure to cleaning agents and disinfectants containing DDAC and ADBAC may cause work-related asthma, chronic obstructive pulmonary disease, and other respiratory illnesses in occupations such as laundry workers, pharmacists, janitors, nursing/medical assistants, health technicians, and housekeepers., Exposure to QACs was found to significantly increase the risk of nasal symptoms and physician diagnosed asthma at work more than any other potentially hazardous exposures including glutaraldehyde, latex gloves, or chlorinated/bleach products.
Dermal Effects: ADBAC and DDAC are highly irritating to the skin, and long-term exposure may result in skin sensitization or allergic dermatitis. There have been several cases in which workers reported symptoms of skin sensitization. More recent animal studies have documented that mice dermally exposed to these substances developed not only irritation but also allergic sensitization.
Reproductive/Developmental Effects: Some emerging evidence has suggested that exposure to QACs such as DDAC and ADBAC may affect reproduction and development in animals. The SAB noted during their review that these early studies are concerning and warrant follow-up, but that the evidence was not yet conclusive. Mice experienced adverse effects after exposure to a ready-to-use product that contained both ADBAC and DDAC, including decreased fertility, fewer pregnancies, reduced number of offspring, disruption of hormone-regulated processes such as ovulation, and birth defects.,   Exposure to a disinfectant containing both ADBAC and DDAC was associated with delayed neural tube closing in both mice and rats.
Other Human Health Effects: A human biomonitoring study of 43 random volunteers detected measurable concentrations of QACs in the blood of 80% of participants and identified correlations between levels of QACs, cellular disruption and specific biomarkers related to human health. This was the first study to measure QACs in human blood and to find evidence that QAC concentrations may influence important biomarkers. Some recent studies have shown that QACs can worsen inflammation and disrupt overall cellular function and regulation. 
QACs usually go down the drain and to wastewater treatment plants, which remove some but not all of the QACs prior to discharge to the environment. QACs have been found in surface waters, soil, sediments, and wastewater sludge. Researchers have raised concerns for microorganisms and aquatic organisms as well as the impact of QACs on wastewater treatment plants. DDAC and ADBAC are recognized as toxic to aquatic life. They are considered immobile in soil by both EPA and ECHA. Due to their low volatility, they are expected to bind to sediments and soils. There are also concerns that the overuse of DDAC, ADBAC, and other QACs could lead to development of antibiotic-resistant bacteria.
QACs have also been detected on surfaces long after being used, and in household dust, meaning they may have the potential to persist in the environment, our workplaces, and our homes. A recent study detected 19 different QAC substances in residential dust samples. QACs, the majority of which were ADBAC substances, were found in over 90% of samples taken. When compared to pre-COVID dust samples, the level of QAC concentrations had nearly doubled.