\n Inadvertently, Hunt had become the first scientist<\/a> to uncover how BPA might lead to chromosomal and reproductive issues in people, including infertility<\/a>, fetal abnormalities<\/a>, low birth weight<\/a>, and brain and behavior disorders <\/a>in infants and children<\/a>.\n <\/p>\n \n Nearly a decade later, Hunt \u2014 who calls herself the \u201caccidental toxicologist\u201d \u2014 once again traced a reproductive crisis in her lab to an unexpected chemical exposure: quaternary ammonium compounds, or QACs.\n <\/p>\n \n Classified as pesticides<\/a>, QACs are the active ingredients in many popular hand sanitizers and disinfectants frequently used in homes, offices, daycare centers, schools, nursing homes and hospitals. The compounds are also found<\/a> in baby wipes, air fresheners, laundry supplies, eye drops, nasal sprays and personal care products such as shampoos, mouthwash and toothpaste.\n <\/p>\n \n Developed in 1916<\/a> and widely used by the 1940s, QACs \u2014 like bisphenols \u2014 were long assumed harmless when used as directed. Emerging research, however, is challenging that conclusion.\n <\/p>\n \n \u201cWe now know QACs can be detected in human blood. There\u2019s also a growing infertility problem, and based on studies in mice, I would expect that QACs are contributing,\u201d said Hunt, a regents professor in the School of Molecular Biosciences at Washington State University in Pullman.\n <\/p>\n \n \u201cThese QACs are fantastic because they kill everything, but that doesn\u2019t make them safe for people to use.\u201d\n <\/p>\n \n Lab and animal studies over the past decade have raised concerns about QACs\u2019 effects on inflammation<\/a>, the immune and respiratory systems<\/a>, reproductive hormones, and the developing brain<\/a>.\n <\/p>\n \n The compounds exacerbate asthma and chronic lung disease, \u201cespecially in occupational settings, where they have been most studied,\u201d said Amina Salamova, an assistant professor of environmental health at Emory University\u2019s Rollins School of Public Health in Atlanta.\n <\/p>\n \n Pilot studies have detected QACs in human blood serum<\/a>, breast milk<\/a>, urine and feces<\/a>. Based on human cell and animal studies, QACs \u201cmay also accumulate in the heart, kidneys, digestive tract and lungs,\u201d said Libin Xu, an associate professor of medicinal chemistry at the University of Washington School of Pharmacy in Seattle, who studies the compounds.\n <\/p>\n \n The chemicals may also harm cells in the brain and spinal cord that create myelin, according to a 2024 study<\/a> in human tissue. Myelin functions like rubber coating on an electrical wire, allowing neurons to communicate faster.\n <\/p>\n \n \u201cWithout that protective myelin coating, nerve cells will degenerate and ultimately die. That leads to progressive neurodegeneration in conditions like multiple sclerosis,\u201d said senior study author Paul Tesar, a professor of genetics and neurosciences at Case Western Reserve University in Cleveland.\n <\/p>\n \n Mitochondria<\/a> \u2014 the cell\u2019s powerhouse \u2014 may also be impacted by QACs. Both human<\/a> and animal studies found the chemicals damage the ability of mitochondria to make adenosine triphosphate, or ATP.\n <\/p>\n \n \u201cATP is the chemical energy that all of your body runs on \u2014 it\u2019s what makes your brain work and your muscles function when they contract,\u201d said Gino Cortopassi, a professor of molecular biosciences at the University of California, Davis, who has studied mitochondria<\/a> for over three decades.\n <\/p>\n \n Despite growing alarm, researchers fear QACs are \u201cflying under the radar\u201d of public concern, said Rebecca Fuoco, director of science communications for the Green Science Policy Institute, a nonprofit in Berkeley, California, that investigates harmful chemicals.\n <\/p>\n \n \u201cQuaternary ammonium compounds are on track to be the next major toxic chemical story, combining elements of PFAS<\/a>, phthalates<\/a> and flame retardants<\/a>,\u201d Fuoco said. \u201cWe\u2019re worried the public knows nothing about these dangers.\u201d\n <\/p>\n \n A spokesperson for the American Cleaning Institute, or ACI, a nonprofit trade organization that represents industry, told CNN in an email that any claim QACs are the \u201cnext PFAS\u201d is not supported by the available science and will be \u201cmore likely to alarm consumers than help them understand actual risk.\u201d\n <\/p>\n \n \u201cThe fact that a substance can be detected in blood, breast milk, urine or other samples does not, by itself, prove an adverse health effect,\u201d said Dan Selechnik, ACI\u2019s director of environmental health.\n <\/p>\n \n In addition, the relevance of cell and animal studies depends on the dose, route of exposure, duration and how closely the study conditions reflect real-world use, said Mike Gruber, interim CEO for the Household & Commercial Products Association.\n <\/p>\n \n \u201cThe responsible approach is neither to dismiss emerging research nor to treat preliminary findings as settled science,\u201d Gruber said in an email. \u201cThe EPA evaluates each product\u2019s safety and effectiveness before registration and has the authority to require additional data, label changes, use restrictions, or other actions as scientific evidence evolves.\u201d\n <\/p>\n \n Hunt\u2019s findings could have been dismissed as a one-lab anomaly. Then, in 2008, she got a call from Terry Hrubec, a reproductive researcher in Virginia who was seeing alarming fetal deformities in her control mice \u2014 animals that don\u2019t receive an experimental treatment.\n <\/p>\n \n In Hrubec\u2019s lab, the malformations took a different form \u2014 neural tube defects similar to spina bifida in humans, in which parts of the spinal column fail to close, or anencephaly, where the skull and brain never fully develop.\n <\/p>\n \n \u201cMany of the mice carried fetuses with partial brains, brain tissue growing out of the skull, or no brains at all. They also had openings in their spinal columns,\u201d said Hrubec, a professor of anatomy and embryology at the Edward Via College of Osteopathic Medicine in Blacksburg, Virginia.\n <\/p>\n \n One in 33 babies<\/a> in the United States are born with a birth defect, according to the US Centers for Disease Control and Prevention. Heart defects are the most common congenital malformations, followed by neural tube defects<\/a>, which are typically carried to term.\n <\/p>\n \n In Hrubec\u2019s mice, however, fetuses with deformities of the brain and spine were dying early in the pregnancy and disappearing. In animals that have litters, such as rodents, dogs, cats, pigs and kangaroos, a dead fetus will be reabsorbed by the mother\u2019s body to protect the rest of her offspring.\n <\/p>\n \n \u201cThis is a key reason industry studies the EPA uses to determine<\/a> safety<\/a> have not found these birth defects \u2014 the studies looked for deformities much later in the pregnancy, when the malformed fetus is no longer there,\u201d she said.\n <\/p>\n \n Hunt and Hrubec began collaborating, dosing mice in their labs with QAC-laced food for six months. The findings, published in 2014<\/a>, found a dramatic drop in a mouse\u2019s ability to become pregnant and successfully carry a fetus to term.\n <\/p>\n \n Female mice dosed with QACs lost interest in food, became lethargic and short of breath, and began to lose muscle control during late pregnancy. The study animals also experienced vaginal hemorrhages and difficult labor \u2014 more than one-third died close to giving birth.\n <\/p>\n \n \u201cIn later studies<\/a>, we found QACs directly target the placenta of the mice, which delivers oxygen and nutrients to the baby,\u201d Hrubec said. \u201cLevels of inflammation rose in the placenta and were highest in fetuses with the neural tube defects.\u201d\n <\/p>\n \n Higher levels of pro-inflammatory proteins from any source have been linked to neurological and sensory processing differences in conditions such as attention deficit hyperactivity disorder, or ADHD, and autism<\/a>.\n <\/p>\n \n Quaternary ammonium compounds can also accumulate in the testicles, Hrubec said. In two of three studies, male mice exposed to QACs had lower sperm counts<\/a> and less mobile sperm<\/a>. Hrubec\u2019s lab has not yet studied the cause, but there are clues: QACs may damage bodily functions that impact sperm production, maturation and motility.\n <\/p>\n \n \u201cAs for what this means for people, that is always the big question when going from animal studies to humans,\u201d Hrubec said. \u201cSome of the concentrations we detected in people were as high as those used in the animal and cell culture studies, so we know the exposures are equivalent. Clearly the potential exists to affect fertility in people, it just is not yet known.\u201d\n <\/p>\n \n Use of QACs soared during the Covid-19 pandemic as frightened masses sanitized themselves and nearly everything else in sight. One small study found levels of QAC in household dust rose 62% during the pandemic<\/a> while levels in human blood rose 77%<\/a> in just one year.\n <\/p>\n \n Fear of Covid has declined, but consumer interest in deeply sanitizing homes, offices and schools has not diminished. Estimates<\/a> put the global market for QACs in 2026 at $1.17 billion, more than a 21% increase since 2019. Today, the compounds remain the main ingredients in hundreds of products on the US Environmental Protection Agency\u2019s list of disinfectants approved to combat<\/a> SARS-CoV-2.\n <\/p>\n \n \u201cBenzalkonium chloride, or BAC, also known as alkyl dimethyl benzyl ammonium chloride, or ADBAC, is the most widely used QAC,\u201d Fuoco said. \u201cIt\u2019s found in antibacterial hand soaps, disinfecting wipes and sprays, laundry sanitizers and more.\n <\/p>\n \n \u201cDidecyldimethylammonium chloride, or DDAC, is also widely used and often combined with BAC in the same disinfectant formulations.\u201d\n <\/p>\n \n Risk rises when QACs are used frequently, such as in daycares<\/a>, gyms, nursing homes, schools, hospitals, offices and industrial sites.\n <\/p>\n \n Emory University\u2019s Salamova, who studies indoor exposure, found levels of QACs in dust in daycare<\/a> and assisted living care facilities<\/a> to be about three times higher than in residential homes.\n <\/p>\n \n \u201cWhen my kids were young in the infant room at daycare, the caretakers would take the toys a baby was putting in their mouth, drop it into the QAC disinfectant, bring it back out, shake it off, and hand it to another infant,\u201d Hrubec said.\n <\/p>\n \n Caregivers likely aren\u2019t aware of the potential harms of QACs and feel they are keeping the children safe, but it\u2019s wasted effort, experts say. Unless that toy was cleaned before it was disinfected, the germs remain.\n <\/p>\n \n \u201cUsing a disinfectant without first cleaning isn\u2019t effective at all,\u201d Hrubec said. \u201cAnd what\u2019s even more frustrating is that we don\u2019t need to disinfect everything. Manufacturers advertise that these chemicals kill 99% of germs. But soap and water wash away 99% of germs \u2014 when you rinse, the bacteria and germs are gone.\u201d\n <\/p>\n \n And that, experts say, is the troubling irony about QACs: People are increasingly exposed to potentially harmful chemicals at times when ordinary soap and water would be enough.\n <\/p>\n \n \u201cOur message is not to stop cleaning or disinfecting,\u201d Salamova said. \u201cOur message is to understand when you can just clean versus when you actually need to disinfect. If someone is sick with an infectious disease, that\u2019s a time to disinfect. But you don\u2019t need to disinfect each time you clean.\u201d\n <\/p>\n \n A key way to avoid QACs is to check the labels of products marketed as \u201cantibacterial,\u201d \u201cantimicrobial,\u201d \u201cdisinfecting,\u201d \u201csanitizing\u201d or \u201cgerm-killing, Fuoco said: \u201cBe wary of claims on product labels such as \u2018odor control\u2019 or \u2018lasting protection\u2019 or surfaces that \u2018stay cleaner longer,\u2019 which can also signal added antimicrobials.\u201d\n <\/p>\n \n When a disinfectant is necessary, Hunt and other experts say products with citric acid, hydrogen peroxide and ethyl alcohol, such as alcohol wipes, are safer alternatives.\n <\/p>\n \n For Hunt, however, the problem is greater than what sits under the kitchen sink. She believes QACs repeat the story of BPA: A chemical becomes trusted and embedded in daily life \u2014 and only later do scientists begin to uncover its true cost.\n <\/p>\n \n \u201cWe have manufactured QACs and released them into commerce before we really understood how to monitor them in human bodies,\u201d she said. \u201cI just don\u2019t think we should be coming in contact with these chemicals.\u201d\n <\/p>\n![\"A](\"https:\/\/www.newsbeep.com\/us\/wp-content\/uploads\/2026\/08\/20260805-qacs-mice-fetuses-01.jpg\")
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Nearly 50% of disinfectants and food surface sanitizers sold in the US contain QACs.” class=”image_large__dam-img image_large__dam-img–loading” onload=’this.classList.remove(‘image_large__dam-img–loading’)’ onerror=”imageLoadError(this)” height=”1693″ width=”2500″ loading=’lazy’\/><\/p>\n