The Legal Hair-Conditioning Ingredient Killing Fetuses

Are listed on the label

Quats 2

Quats 2

Part One

January 2009. Toxicologist Terry Hrubec was looking through her microscope at the gap in the neural tube of a 10-day-old mouse embryo. The neural tube is a collection of cells that will ultimately become the brain and spinal cord in mice and humans. The highly magnified image of the divide troubled Hrubec. She expected to see examples like this of the drug's toxicity to the developing fetus. But, in this case, she was troubled and perplexed.

The point of her work was to learn about the causes of neural tube birth defects; gaps in neural tubes are signs of dangerous birth defects and pregnancies gone wrong. If the neural tube were developing properly it would be completely joined. The trouble was that she expected to see this gap in the neural tubes of embryos whose mothers were exposed to the toxic drugs she had been studying. The drugs were known to cause birth defects. This was different.

In this case, she was finding them in the control group—the mice that weren’t suppose to be exposed to the drug. Some 10 percent of the control group had birth defects.

Neural tube defects (NTDs) are severe congenital malformations. Around 1 in every 1000 pregnancies experience them. Thankfully, NTDs have been declining in countries where food is fortified with folic acid. That is why doctors tell pregnant patients to use this supplement and it is added to cereal and bread and other foods as part of their enrichment after being refined. She repeated everything to make sure she hadn’t made a mistake. She talked to the staff. Same old mice. Same old diet.

But there was one change.

To keep the animals free from pathogens the cages were sprayed with a disinfectant. The animal facility at Virginia Tech had just added a new disinfectant to their protocol. Manual disease prevention included manually cleaning everything with chlorine-based formulations. In the fall of 2008, the staff switched to a different kind of cleaner using a family of environmentally persistent chemicals called quats or quaternium ammonium compounds. In this case, the disinfectant was exposing the animals to alkyldimethylbenzylammonium chloride (ADBAC) and didecyldimethylammonium chloride (DDAC). It hadn’t taken long for the quats to exert their effects on the lab animals.

By 2014, she had begun publishing her findings in the journal Reproductive Toxicology. Her team found that decreased reproductive performance in laboratory mice coincided with the introduction of a disinfectant containing quats. Disconcertingly, these compounds “were detected in caging material over a period of several months following cessation of disinfectant use.” Breeding pairs exposed for six months to the quat-based disinfectant exhibited decreases in fertility and fecundity: increased time to first litter, longer pregnancy intervals, fewer pups per litter, and fewer pregnancies.


Melin VE, Potineni H, Hunt P, Griswold J, Siems B, Werre SR, Hrubec TC. Exposure to common quaternary ammonium disinfectants decreases fertility in mice. Reprod Toxicol. 2014 Dec;50:163-70. doi: 10.1016/j.reprotox.2014.07.071. Epub 2014 Aug 14. PMID: 25483128; PMCID: PMC4260154.] “Significant morbidity” in near term mother mice was also observed. “In summary, exposure to a common QAC disinfectant mixture significantly impaired reproductive health in mice.”

Read Part Two: Hair-Conditioner Ingredient Harms Both Sexes' Fertility

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