We all want the best for our cats. We look for quality ingredients, compare nutritional labels and invest in food that promises to keep our feline companions healthy. But have you ever wondered what might be present in your cat’s food beyond the ingredients listed on the packaging?
A new study by the Clean Label Project has brought renewed attention to an important question: How do we know whether our cat’s food is as clean as we think it is?
Published on 2 October 2026, the organisation’s latest Cat Food Category Report examined 100 cat food products across 62 brands, screening them for more than 122 environmental contaminants and toxins. The findings highlight the importance of looking beyond marketing claims and ingredient lists when choosing food for our cats.
The results deserve attention, but they also require context. Detecting a contaminant does not automatically mean a product is dangerous, and the study does not establish that the products tested cause illness in cats.
Let’s explore what the research found and what cat parents can take away from it.
1. What did the Clean Label Project discover?
The Clean Label Project purchased and tested 100 cat food products across three categories:
- Dry food: 31 products
- Wet food: 40 products, including canned and pouch formats
- Air-dried and freeze-dried food: 29 products
Testing was conducted by an independent analytical laboratory accredited to ISO 17025 for the relevant testing methods.
The study screened products for heavy metals, herbicide residues, plastic-related chemicals, processing contaminants and other substances.
Some of the headline findings were striking:
- Lead was detected in 99% of products tested.
- Cadmium was detected in 96%.
- Arsenic was detected in 94%.
- Fish- and seafood-based foods had approximately 18 times more mercury than other foods, after accounting for food format.
- DEHP, a plasticizer used in some plastics, was detected in 48 of the 100 products.
These figures describe the products included in this particular study. They do not mean that 99% of all cat foods are unsafe, nor do they establish that every product containing these substances poses a health risk.
Read the original research: Clean Label Project — Cat Food Study
2. Heavy metals: Should cat parents be concerned?
Heavy metals such as lead, cadmium, arsenic and mercury can enter food through environmental contamination of soil, water and ingredients.
Because cats may eat the same food every day for years, the amount of a contaminant in their regular diet is worth considering. Repeated exposure is particularly relevant when assessing substances that can harm the body at sufficient doses.
However, the presence of a heavy metal alone does not tell us whether a food is harmful. The concentration, chemical form, amount consumed, duration of exposure and applicable safety standards all matter.
Lead
Lead was detected in 99% of the products tested. The study also found that dry cat food contained roughly three times as much lead per 1,000 kilocalories as wet or air-dried food.
Interestingly, the researchers did not find a strong relationship between lead levels and one particular protein source. The higher levels in dry food therefore cannot simply be explained by whether the recipe contains chicken or fish.
Cadmium
Cadmium was detected in 96% of the products. Fish- and seafood-based foods contained approximately 2.5 times as much cadmium as other foods in the study.
Marine organisms can accumulate cadmium from their environment, which may help explain this association.
Arsenic
Arsenic was detected in 94% of the products. Its presence can be influenced by environmental sources and the ingredients used in a food. However, total arsenic detection alone does not establish the toxicity of an individual product; the chemical form of arsenic is also important.
What this means: Rather than assuming that every product containing a detectable amount of a metal is dangerous, look for brands that can demonstrate consistent quality control and explain how they monitor contaminants in their finished products.
3. Does fish-based cat food contain more mercury?
One of the most notable findings concerned mercury.
According to the study, fish- and seafood-based cat foods contained approximately 18 times more mercury than other products after accounting for whether the food was wet or dry.
The researchers also found that nearly half of the fish-based products ranked among those with the highest mercury levels, while none of the poultry-based products did.
This does not mean fish is inherently bad for cats. Fish can provide valuable nutrients, and some fish-based products performed well in the study. The findings instead suggest that protein source and ingredient sourcing deserve closer attention.
If your cat eats a fish-based diet exclusively, consider discussing a nutritionally complete alternative protein source with your veterinarian. Rotating between suitable complete diets may help diversify exposure, although it cannot guarantee lower overall contaminant intake.
Remember that cats have specific nutritional requirements. Any change in diet should preserve nutritional completeness and suit your cat’s individual needs.
4. Is dry food less safe than wet food?
Not necessarily.
The study found higher lead levels in dry food, but that does not establish that all dry food is less safe than wet food.
One important detail is how the researchers compared results. They expressed contaminant levels per 1,000 kilocalories rather than simply per kilogram of food. Wet food contains considerably more water, so a comparison based only on food weight could make it appear cleaner simply because its contaminants are diluted by moisture.
When the researchers compared products on a calorie-adjusted basis, dry food contained roughly three times as much lead as wet or air-dried food.
However, food format was not the strongest predictor of whether a product met the Clean Label Project’s standard. Protein source showed a much larger difference.
The takeaway: Do not choose dry or wet food based on this finding alone. Consider nutritional completeness, your cat’s hydration needs, individual health requirements and the quality controls behind the product.
5. Herbicide residues and plant-based ingredients
The study also investigated glyphosate, a widely used herbicide, and its breakdown product, AMPA.
Glyphosate was detected at measurable levels in 37% of the products, while AMPA was detected in 12%.
The researchers observed that glyphosate levels increased by approximately 40% for each additional plant ingredient among the first ten ingredients listed on the packaging.
This is an association, not proof that every plant ingredient contains glyphosate or that plant-based ingredients are inherently unsafe. Residues may depend on agricultural practices, sourcing and other factors.
The report also raised an interesting point about ingredient lists: in 35 of the 100 products, the first-listed meat or fish ingredient was outnumbered by plant ingredients within the first ten ingredients.
This can happen when a recipe includes several different plant ingredients, including different forms of the same crop.
What should you look for?
Read beyond the first ingredient. Understand the overall composition of the recipe and look for manufacturers that can explain their ingredient sourcing and testing practices.
A long ingredient list is not automatically a red flag, and plant ingredients are not automatically inferior. What matters is the complete nutritional profile, ingredient quality and the finished product's safety.
6. What about chemicals from food packaging?
Another finding involved DEHP, a type of phthalate used in some plastic materials.
Clean Label Project detected DEHP in 48 out of 100 products. The report found similar detection rates across dry and wet food formats, but canned and pouched products had approximately five times as much DEHP as bagged products in the study.
The researchers suggested that packaging materials and food contact could help explain this difference.
The study also detected acrylamide, a chemical that can form during high-temperature cooking, at measurable levels in four products and at very low levels in another 24 products.
Bisphenols, another group of chemicals that can be associated with packaging, were rarely detected.
These results highlight that food quality involves more than the ingredients themselves. Manufacturing processes, packaging materials and quality controls can all be relevant.
However, detecting a packaging-related chemical does not, by itself, establish that the amount present will harm a cat.
7. Does a premium or natural label mean safer food?
Not necessarily.
Terms such as premium, natural and holistic can sound reassuring, but they do not independently establish that a product has lower contaminant levels.
Clean Label Project's findings suggest that a product's marketing position or headline ingredient may not tell the whole story about its contaminant profile.
The researchers also found that the first ingredient alone did not reliably predict which contaminants would be present at the highest levels.
This is an important reminder for cat parents: a reassuring ingredient list is not a substitute for evidence of product quality and safety.
When evaluating a brand, consider whether it can explain its sourcing practices, nutritional adequacy, manufacturing standards and finished-product testing.
8. How can you choose cat food more confidently?
Although the findings may sound alarming, there are practical steps you can take without becoming fearful of every food label.
1. Ask about finished-product testing
Find out whether the manufacturer regularly tests the finished food for relevant contaminants, including heavy metals.
Testing ingredients alone may not capture everything introduced during manufacturing or packaging. Ask whether testing is routine, how frequently it occurs and whether it covers multiple production batches.
2. Look beyond the first ingredient
Check the complete ingredient list rather than judging a recipe by its first-listed ingredient alone.
Look for transparent ingredient sourcing and a clear explanation of the food's nutritional formulation.
3. Consider protein variety where appropriate
If your cat eats fish-based food exclusively, ask your veterinarian whether another nutritionally complete protein source would be suitable.
Variety is not compulsory for every cat, and some cats need specific diets for medical reasons. Never compromise nutritional adequacy just to achieve variety.
4. Check nutritional completeness
A food with low contaminant levels is not automatically a good diet if it does not meet your cat's nutritional needs.
Choose a food formulated to be complete and balanced for your cat's life stage, and seek veterinary advice if your cat has particular health requirements.
5. Look for credible independent testing
Clean Label Project publishes product rankings and awards based on its own testing and assessment standards.
You can review its resources to understand how the organisation evaluates products and which tested foods ranked favourably.
Useful resources include:
- Clean Label Project Cat Food Study — 2026 findings
- List of tested cat food products with Clean Sixteen rankings
- Clean Label Project category testing methodology and other studies
The Clean Sixteen lists identify products with the lowest contaminant levels within the study's comparison group. A product's absence from the list does not automatically mean it is unsafe.
9. What are the limitations of the study?
It is important to interpret the results fairly.
First, the study examined 100 products across 62 brands. It provides useful information about those samples, but it cannot establish the contaminant profile of every cat food sold worldwide.
Second, each product was tested from a single batch. Contaminant levels can vary between ingredients, production runs and batches, so the results do not necessarily represent every package of a product.
Third, the Clean Label Project compared products using its own assessment standard. Its rankings are useful for comparing the tested samples, but they are not equivalent to a regulatory determination that a particular food is safe or unsafe.
The Pet Food Institute, a US pet food industry association, also questioned whether the study provided sufficient scientific and regulatory context for interpreting its findings. This reinforces the need to distinguish laboratory detection from evidence of actual health risk.
Finally, the study did not establish that the detected concentrations caused illness in cats. Determining health risks requires considering the amount consumed, duration of exposure, toxicological evidence and appropriate safety benchmarks.
These limitations do not make the findings irrelevant. They help us understand what the research tells us—and what it does not.
Final thoughts: Your cat deserves transparency, not fear
So, is your cat food safe?
The most honest answer is that safety cannot be determined by a marketing claim, a short ingredient list or a single laboratory result alone.
Clean Label Project's 2026 findings highlight why transparency, responsible sourcing and consistent quality control matter. They also remind us that even products marketed as premium or natural deserve scrutiny.
As cat parents, we do not need to panic or suddenly change our cats' diets based on a headline. Instead, we can make informed decisions, ask manufacturers better questions and work with veterinarians to choose nutritionally complete food that suits our cats.
Ultimately, feeding our cats well means looking at the bigger picture: nutrition, ingredient quality, manufacturing practices and evidence of safety.
Because our cats depend on us for every meal, they deserve more than promises. They deserve thoughtful choices backed by evidence.
Have questions about your cat's food? Start by asking the manufacturer what it tests for, how often it tests and whether it can demonstrate consistent results across production batches.
Editorial note: This article summarises findings from Clean Label Project's 2026 Cat Food Category Report. The study's results should not be interpreted as proof that every product containing a detectable contaminant is unsafe. Consult a veterinarian for advice about your cat's nutritional needs or any proposed diet changes.