Testing Reveals Widespread Contamination
A comprehensive consumer investigation released exclusively to CNN has found that nearly all tested commercial cat foods contain toxic plastic contaminants, the herbicide glyphosate, and heavy metals including lead, mercury, and arsenic. The analysis, conducted by the Colorado-based nonprofit Clean Label Project, evaluated 100 top-selling cat food products across 62 brands for more than 122 individual contaminants.
According to report author Molly Hamilton, executive director of the organization, toxins were detected across all product formats—wet, dry, and air- or freeze-dried—including items marketed as natural or premium. “Most cats eat the same foods nearly every day, with little variation,” Hamilton told CNN, noting that these contaminants represent an ongoing exposure that may accumulate in feline bodies over their lifetimes. Chronic kidney disease, a leading cause of mortality in older cats, is of particular concern because kidneys filter heavy metals.
Lead, Mercury, and Herbicide Breakdown
The investigation documented lead in 99% of all samples, cadmium in 96%, and arsenic in 94%. Contamination levels varied significantly by protein source and processing method. Dry cat food samples contained roughly three times more lead than wet or air-dried alternatives, while fish- and seafood-based products showed mercury levels approximately 18 times higher and cadmium levels about 2.5 times higher than foods formulated with alternative proteins.
Glyphosate, the world’s most widely used agricultural herbicide, was detected in 37% of tested items. The study established a direct correlation between plant ingredients and herbicide concentration: products featuring two plant ingredients among their top ten label components contained about 40% more glyphosate than those with just one, while formulations with five plant ingredients carried nearly four times the concentration. Furthermore, di(2-ethylhexyl) phthalate (DEHP), a chemical utilized in PVC plastics, appeared in about half of the evaluated products, with peak concentrations identified in canned and pouch packaging.
Industry Response and Consumer Guidance
Industry representatives pushed back against the findings, emphasizing established safety protocols. Elise Fennig, CEO of the Pet Food Institute, stated in an email that manufacturers implement comprehensive quality assurance programs. These include strict ingredient specifications, supplier verification, traceability frameworks, and science-based preventive controls designed to maintain product safety and consistency.
Independent experts, however, argue that oversight remains insufficient. Ryan Babadi, science director for Toxic Free Future, maintained that major retailers carry a responsibility to require suppliers to eliminate harmful chemicals from pet food and packaging. To mitigate daily exposure risks, the Clean Label Project advises pet owners to rotate protein sources, carefully inspect ingredient labels, and contact manufacturers directly regarding their contaminant testing frequency.