The US Environmental Protection Agency (EPA) is being sued over concerns that toxic pesticides in pet flea collars can harm children’s brains and nervous systems. The Natural Resources Defense Council (NRDC) filed a lawsuit against the EPA after the government agency failed to respond to NRDC’s petitions to ban hazardous pesticides used in pet flea treatment products, according to a press release.

The EPA has restricted neurotoxic pesticides from household use, but continues to allow the hazardous pesticides neurotoxic propoxur and tetrachlorvinphos (TCVP) to be used in flea treatments for dogs and cats, the NRDC notes. By suing the EPA, NRDC hopes to force the agency to respond to petitions to ban the neurotoxins from all pet uses.

Flea collars for dogs and cats are designed to leave residues of pesticide on pets’ fur. This exposes humans to the toxic chemicals when they come in contact with their pets. For children, this is an extreme concern because the chemicals can be absorbed through the skin or ingested if a child puts their hands in their mouth. Propoxur and TCVP are known to be toxic to brain development and nervous system communication, and can cause cancer.

Children are more vulnerable because their brains and bodies are still developing and because they are more prone to play with pets and then put their hands in their mouths, increasing the amount of pesticides that can enter their bodies. In large doses, the chemicals can also harm or kill pets.

“These flea collars leave a toxic residue on pets’ fur, exposing children to chemicals which can have harmful effects on their brains, similar to those from lead” Miriam Rotkin-Ellman, a senior scientist with NRDC’s health program said in a press release. “Luckily, there are less-toxic alternatives readily available to control fleas. Nearly a decade has passed since NRDC urged EPA to get these toxic chemical collars off store shelves, but the agency continues to drag its feet.”

In 2009, the NRDC released its Poison on Pets II report, which noted that pesticides can stay on pets’ fur for weeks after a flea collar is used on an animal. Residue levels in the study were found to be high enough to pose a threat to children’s’ neurological systems. The following year, the EPA published an initial exposure assessment, which concluded that the risks to children from exposure to pets with propoxur flea collars were “of concern,” according to the NRDC.

The NRDC filed a petition seeking a ban on using neurotoxic chemicals in pet flea collars in 2007 and filed a supplement to that petition in 2011. No final decision has been made on the petition. In 2009, the NRDC filed a petition with the EPA seeking to ban the use of TCVP in pet collars. The EPA has also never responded to that petition.

NRDC’s Green Paws Product Guide lists alternative methods to pet flea control and ranks more than 125 flea and tick products based on their safeness to people and animals. The council recommends avoiding flea collar brands that use the neurotoxic chemicals, such as Sergeant’s Pet Care Products, Inc., Wellmark International and Hartz Mountain Corporation.

Alisha is a writer and researcher with Ring of Fire. You can follow her on Twitter @childoftheearth.