Lead was detected in 99% of cat food products tested in a new study by the Clean Label Project, with cadmium found in 96% and arsenic in 94%. The organization tested 100 products from 62 brands for more than 122 environmental contaminants and toxins.
The Pet Food Institute (PFI) challenged the study. "A study by the Clean Label Project risks misleading cat owners because it lacks important scientific and regulatory context needed to interpret its findings," said Elise Fennig, CEO of the Pet Food Institute, in a statement to Petfood Industry.
Fennig said the study evaluated products against a proprietary standard rather than regulatory benchmarks.
"The Clean Label Project study evaluates products against a proprietary 'purity standard' rather than established regulatory standards or science-based risk assessments," she said. "It is unclear whether this research underwent scientific or veterinarian review, or how or why Clean Label Project's proprietary methodology differs from industry and regulatory body standards.
"While the authors acknowledge that the substances identified are not intentionally added to cat food and may occur naturally in the environment, the study does not provide the risk-based context necessary to determine whether the reported findings are relevant to cat health or product safety," she explained.
"Detectable amounts of certain metals are present in the environment and can be found in our air, water and soil," Fennig said. "The mere presence of a metal does not indicate harm. As the U.S. Food and Drug Administration (FDA) has noted, whether a metal is harmful depends on multiple factors, including the level and duration of exposure."
She also noted that "the Clean Label Project findings are based on a single batch of each product, limiting the conclusions that can be drawn from the results."
"In the United States, pet food is among the most highly regulated food products and must meet both federal and state requirements," Fennig said. "Pet food manufacturers implement comprehensive food safety and quality assurance programs that include ingredient specifications, supplier verification, testing protocols, traceability systems and science-based preventive controls designed to ensure products are safe, nutritious and consistent."
"Cat owners should feel confident that the food they feed their pets is safe and produced according to rigorous regulatory and quality standards," she said. "U.S. pet food makers remain committed to continuous improvement, scientific innovation and producing the safest possible products to support the long-term health and well-being of cats and dogs."
Fish-based products linked to higher mercury
The Clean Label Project reported that protein source was more closely tied to contaminant levels than food format. While 84.8% of poultry-based products met the organization's standard, 25.7% of fish and seafood products did, a 59.1-percentage-point gap. Dry and wet formats were within one percentage point of each other on meeting the standard.
After accounting for format, products with fish or seafood in their names had about 18 times more mercury than other products. Among wet foods, fish-based products had about 28 times as much mercury as wet foods made with other proteins. Nearly half (48.6%) of fish and seafood products ranked among the highest for mercury; no poultry-based products did. Products without fish in the name that contained a marine ingredient also tended to have more mercury than products with no marine ingredients.
Fish-based products had about 2.5 times more cadmium than other products, according to the report.
Lead higher in dry food
Dry food had about three times more lead than wet or air-dried food on a per-calorie basis, a difference that held after considering protein source. Lead levels were not linked to a specific protein type. The highest-ranking products had about 3.5 times more lead than the typical product, the report stated.
Glyphosate, DEHP and packaging chemicals
Glyphosate was detected in 37% of products and its breakdown product, AMPA, in 12%. Each additional plant ingredient among the first 10 listed ingredients was associated with about 40% higher glyphosate levels.
Bis(2-ethylhexyl) phthalate (DEHP), a plasticizer, was detected in 48 of 100 products at similar rates in dry and wet foods. Where detected, canned and pouched products had about five times more DEHP than bagged products. Dibutyl phthalate was detected in 26 products but never at a quantifiable level, and dihexyl phthalate was not detected.
Acrylamide was found at measurable levels in four products and at very low levels in 24 more. BPA was found in two products and BPS in one, which the Clean Label Project attributed to a shift away from bisphenols in packaging.
First ingredient and ingredient splitting
In 35 of 100 products, the first-listed ingredient was outnumbered by ingredients from a different category within the first 10 items, most often meat or fish followed mostly by plant ingredients. The rate was consistent across dry (35.5%), wet (35%) and air-dried (35.7%) products. The report noted that ingredient splitting is allowed in commercial pet food manufacturing and stated that products in which plant ingredients outnumbered the first ingredient tended to have higher lead levels.
Combining the study with prior testing, for a total of 541 samples across 87 brands, the organization found herring meal, tuna and fish broth were most strongly associated with contamination. Products containing herring meal ranked among the most contaminated 10% of products 60% of the time. Turmeric ranked fourth.
Methodology
The Clean Label Project purchased 31 dry, 40 wet (canned and pouch) and 29 air-dried or freeze-dried products. Testing was performed by an independent analytical chemistry laboratory with ISO 17025 accreditation for the methods used. Heavy metals were measured by inductively coupled plasma mass spectrometry, and other contaminants by liquid chromatography tandem mass spectrometry.
Results were reported per 1,000 kilocalories rather than per kilogram of food. Products ranged from 547 to 5,290 kcal/kg, and the organization said measuring by weight would make wet food appear cleaner because of its water content.
Click here for more information or to download the full report.
