Clean Label Project Cat Food | Rating System Explained

Most cat food labels list ingredients but stay silent on what isn’t declared — trace heavy metals from soil, BPA from can linings, or pesticide residues that slip through the supply chain. The Clean Label Project fills that gap by independently testing over 900 cat food products for 130 contaminants and distilling everything into a single star rating. The system is useful, but before you reorganize your pantry around it, there are limits and controversies worth knowing.

What Is the Clean Label Project?

The Clean Label Project is a U.S.-based nonprofit that tests consumer products for industrial and environmental contaminants that standard labels don’t cover. For pet food, it has screened over 900 products from 71 brands through its lab partner Ellipse Analytics, which uses ISO 17025-accredited methods. The testing targets 130 different toxins including heavy metals (arsenic, cadmium, lead, mercury), bisphenols (BPA and BPS), phthalates, glyphosate, pesticides, mycotoxins, and acrylamide.

Each tested product receives a star rating from 1 to 5 based on the number and level of contaminants detected. The organization does not manufacture or sell any food — it only rates what’s already on the shelf.

How the Clean Label Project Rates Cat Food: Star System Explained

Using the Clean Label Project Cat Food Database: How to Search

The CLP database is free and requires no account. Go to cleanlabelproject.org and click the teal search box on the homepage. From there you can filter by brand name, protein source (chicken, turkey, fish), or specific product name. The results display each tested variant with its star rating.

Critical detail: ratings vary by flavor, not just brand. A brand’s turkey recipe might earn 5 stars while its fish recipe scores 1 star within the same product line. Always check the specific flavor and formula rather than relying on the brand’s overall reputation. For context on how the project approaches its testing, the ABC15 overview of CLP pet food ratings covers the scope and limitations of their screening process.

Key Contaminants Screened in CLP Testing

CLP’s lab work covers four main contaminant groups, each weighted differently in the final score. The table below shows the categories and their relative influence.

One thing the project does not publish: raw parts-per-million data from individual tests. Only the aggregate star ratings are made public, which means independent researchers cannot verify the scores or compare specific contaminant loads between products. Critics have pointed this out as a significant transparency gap.

What Critics Say About Clean Label Project Ratings

The project has drawn sharp pushback from both industry groups and pet food analysts. The Pet Food Institute issued a formal statement saying CLP’s 2026 dog food study “lacks essential scientific and regulatory context” and could mislead consumers about actual risk. Whole Dog Journal has noted that all tested contaminant levels in CLP’s studies fall below established safety thresholds from AAFCO and the National Research Council — meaning even 1-star products are within limits considered safe for animals.

A major methodological concern: CLP does not adjust for moisture content when comparing dry food to wet food. Dry food has very little water, so contaminant concentrations per gram naturally appear higher even when the absolute amount per serving is equivalent. This means dry foods may be unfairly penalized against wet foods in the rating system.

Should You Trust Clean Label Project Ratings for Your Cat?

The honest answer: CLP ratings are useful as one data point but should not be the only factor driving your cat’s diet. The project provides real transparency about industrial contaminants that no other rating system covers. For owners who want to minimize every possible extraneous substance, the 5-star and certified products are genuinely cleaner options backed by lab testing.

Where the system falls short: it does not tell you whether the difference between a 3-star and a 5-star product matters for your cat’s actual health, because all tested levels are below known safety thresholds. The ratings also ignore nutritional quality, digestibility, ingredient sourcing, and life-stage appropriateness — factors that many veterinary nutritionists rank well above trace contaminant levels.

Your best approach: use the CLP database to identify products with lower contaminant loads, then cross-reference those options with nutritional standards and your veterinarian’s recommendations. For a practical starting point that balances purity with complete nutrition, check out our roundup of the best clean cat food products — each option has been reviewed for both ingredient quality and contaminant transparency.