29
Sep
EPA Reverses on Decision to Ban Flea Collars with Toxic Pesticide, Leaving Children at Risk
(Beyond Pesticides, September 29, 2023) In unsurprising news, the Environmental Protection Agency (EPA) has reversed itself and decided not to ban a dangerous pesticide: tetrachlorovenphos (TCVP) used in pet flea collars and other flea products. This is despite its own earlier decision to ban TCVP in pet collars and scathing criticism of its methods and conclusions by the courts.
First registered in 1966, TCVP belongs to the notoriously toxic organophosphate chemical family and is classified by the World Health Organization as “possibly carcinogenic to humans.” It was originally registered to Shell Chemical, then to E.I. duPont de Nemours, then to Hartz Mountain Corporation and Fermenta Animal Health Company. Early on, it was registered for use on food crops and livestock, but the crop uses were voluntarily de-registered in 1987. It is still widely used on pets and farm animals. In 1995, EPA issued the opinion that “all uses of tetrachlorvinphos, with the exception of oral feed-through larvicide treatment to livestock intended for food use, will not cause unreasonable risk to humans or the environment.” Since then, the agency has contorted itself repeatedly to allow TCVP to remain on the market.
There is little research available on TCVP’s human health effects; the Agency for Toxic Substances and Disease Registry does not even have a fact sheet for the compound, although it does have one for the related chemical chlorfenvinphos, which is no longer registered for any use in the U.S.
The lack of human data allows EPA to base its decision on manufacturer-commissioned animal studies. The standard battery of toxicological screenings involves exposing rats, rabbits, and other animals to various doses of the test chemical. The analysis of their responses focuses on tumor formation, anomalously large or small internal organs, reproductive dysfunction, birth defects in offspring, skin sensitivity, genetic mutations and other potential endpoints, but few consider chronic low-dose exposures and whether this may lead to neurological problems.
This is especially problematic with pet flea collars, which millions of children are exposed to. The TCVP collars, manufactured by Hartz Mountain, distribute the pesticide gradually over the animal’s body, most of it in the form of dust. EPA has used, according to some advocates, an egregiously illogical rationale for failing to cancel TCVP registration for flea treatments. In its risk assessments, for example, EPA has assumed that children play with pets for an hour a day, without considering whether children may also sleep with pets, and whether households may have more than one pet.
Children are especially vulnerable to toxic substances that interfere with development, especially brain development. Organophosphates inhibit the activity of acetylcholinesterase, an enzyme crucial for effective neurotransmitter function. The effect is irreversible and can lead to cognitive deficits, attention deficits, and motor problems in exposed children. In pets, which receive the highest exposures in home settings, organophosphate exposure can cause nervousness, drooling, seizures and death. EPA has previously determined that all organophosphates have a “common mechanism of toxicity,” (see also EPA cumulative risk assessment of organophosphates) so to determine allowable exposure it must aggregate all food and nonfood exposure to determine allowable risk to human health.
The animal studies used in pesticide registrations are not designed to measure chronic exposures over time, but rather to find those dosage levels where animals begin to show symptoms and the dosage level that kills half the dosage group. Regulatory toxicologists generally analyze only gross organ features like size and weight, and the tests do not capture subtle neurological changes.
It is worth looking in detail at EPA’s actions regarding TCVP in the decades after its initial registration. The most recent registration was in 2006, and the agency has been dawdling ever since over the completion of the current reregistration process. EPA had already canceled all other indoor uses for TCVP out of concern for children’s neurological development, but it has consistently resisted attempts to extend the cancellation to flea collars and liquid treatments.
Most of the impetus for canceling TCVP has come via litigation by the Natural Resources Defense Council. The NRDC released an issue paper in 2009 noting that TCVP residues can remain in a pet’s fur for weeks after application at levels up to 1,000 times the EPA’s acceptable levels. NRDC also petitioned EPA in 2009 and sued in 2014, 2015 and 2019 to cancel the pet product registration, arguing that dust-infused flea collars transfer TCVP more easily than liquid-based treatments. Hartz Mountain joined EPA against NRDC and stressed that liquid flea treatments would cost consumers “five to six dollars more a month” than its flea collars.
Five years after its submission, EPA got around to denying NRDC’s 2009 petition. NRDC appealed to the Ninth Circuit Court of Appeals. In 2016, EPA requested remand voluntarily and promised to respond within 90 days after the release of its revised TCVP risk assessment. It did not do so. In late December 2016, EPA emailed NRDC saying it was “EPA’s current intention and belief that the Agency will issue a final revised response to NRDC’s 2009 petition to cancel all pet uses of TCVP within 90 days.” After the 90 days was up in March 2017, EPA notified NRDC saying it would mitigate the risk for pet care use when it conducted its registration review. That was six years ago. EPA not only did not conduct its registration review, but it failed to even list such a review on its schedule. By 2019, EPA had still not published a review schedule for TCVP.
As it often does with registrants, EPA blamed the flea collar company for the delays, resulting in no consequences for the company and continued marketing of the product. EPA had required a study from Hartz Mountain to try to determine how much pesticide, and in what form–dust or liquid—was released from the collars. There were two so-called “torsion studies.” These involved twisting a flea collar to and fro and measuring how much pesticide it released. At first Hartz Mountain tried to say that all the pesticide in the collars was liquid and declined to perform the study. Subsequently the company submitted a torsion study whose methodology had not been approved by EPA ahead of time and EPA gave an estimate of 18 months to get a torsion study properly done and analyzed.
Finally in 2022, Hartz Mountain submitted a new torsion study. A key finding was that 97.2 percent of the dust coming off the flea collar was TCVP—belying EPA’s assumption that only 14.6 percent of the cast-off dust was TCVP. EPA ignored the new finding. On the other hand, EPA accepted the study’s purported finding that only 0.38 percent of the collars’ total weight was released as dust, and the balance of TCVP was released as liquid. EPA also assumed pet owners were trimming a fifth of the collar off once it was placed on the animal. The agency provided no justification for ignoring the major finding until its reply brief in the most recent Ninth Circuit case, in which it said the “Torsion Study used ‘exaggerated twisting conditions…[which] likely overrepresented the amount of [TCVP] in dust extruded from the collars in normal use on pets.’” In that case, the Ninth Circuit opinion rather acidly pointed out that “the TVCP in the collar is specifically designed to be released.”
EPA had published a revised human health risk assessment in 2016 in which it acknowledged the epidemiologic evidence of children’s harm from TCVP exposures and admitted that “more stringent regulatory restrictions are necessary to protect public health.” In its October 2022 response to NRDC’s 2009 petition, EPA stated that it would “grant NRDC’s petition for pet collars” but would do nothing about “pet spray products” because there were no “risks of concern” related to those products.
The latest development is EPA’s September 19 release of its revised human health assessment and decision to reverse last year’s acknowledgment of TCVP’s toxicity, saying instead that the flea collars do not pose an “unacceptable” health risk to children.
Advocates feel strongly that this long and winding road demonstrates that the current regulatory process is corrupt and does not protect public health and the environment. The fact is that EPA succumbs to pressure from the chemical industry and is unlikely to move forward with pesticide restrictions without a public or side agreement with the registrants (pesticide manufacturer) of the chemical in question.
Along with TCVP, controversy has erupted over Seresto flea collars, which are alleged to have killed or sickened thousands of dogs. Seresto collars contain flumethrin, a pyrethroid, and imidacloprid, a neonicotinoid. EPA has not taken any action other than to change the labels slightly and urge the manufacturers and veterinarians to raise awareness of the risks. The controversy is continuing, as Beyond Pesticides has noted.
Beyond Pesticides has long covered a long list of corrupt practices by EPA and the chemical industry, demonstrating that the TCVP saga is nothing new. For example, in 2021 four whistleblower scientists asserted that “risk assessments for both new and existing chemicals were improperly changed by agency managers to eliminate or reduce calculations of risks.”
See also Beyond Pesticides’ coverage of Monsanto/Bayer malfeasance related to dicamba; and our review of EPA’s receptivity to industry influence detailed by The Intercept; whistleblower “outing” of unethical practices at EPA; and the “capture” of EPA by industry. In the latter case, 37 environmental, public health and sustainable agriculture groups led by Public Employees for Environmental Responsibility and Beyond Pesticides, urged the Biden administration to reform the Office of Pesticide Programs as soon as possible.
The letter is available here. It would serve well as a model for citizen letters to President Biden and various other elected officials.
You can also voice your opinion directly to EPA regarding TCVP because its current registration review is still underway and accepting public comment until November 20.
All unattributed positions and opinions in this piece are those of Beyond Pesticides.
Source: Pesticides Registration Review: Proposed Interim Decision for Tetrachlorvinphos; Court Rules EPA Must Revise “Flawed” Analysis of Toxic Chemical TCVP in Pet Flea Collars.
