The Commercial Feed Regulatory Program (CFRP) is dedicated to ensuring feed and food safety for the benefit of the consumer, demonstrated by obtaining at least 60% of samples with an emphasis on feed safety and 40% focused on label compliance and quality assurance. Since 2023 CFRP has performed a heavy metal screen on mineral premix samples which includes analysis of arsenic, cadmium, lead, and mercury.
CFRP analyzed 36 samples in 2023 and 32 samples in the first half of 2024, and results were reported: https://blogs.cdfa.ca.gov/CFRP/index.php/2024/09/03/cfrp-focus-on-feed-safety-heavy-metals/. CFRP analyzed an additional 29 samples in the remainder of 2024, 54 samples in 2025, and to date 55 samples in 2026.
The Association of American Feed Control Officials (AAFCO) published maximum tolerable levels of heavy metals in complete feed (Table 1). The levels are consistent with the maximum tolerance levels for animals published in “Mineral Tolerances of Animals” by the National Research Council, which is based on both animal health and human health regarding accumulation of minerals in edible tissues, milk, and eggs. AAFCO also established levels at which a mineral ingredient would be considered contaminated, and levels at which a mineral ingredient would be prohibited from use in the further manufacturing of feed (Table 1). The tolerance values for mineral ingredients are much higher than the tolerance for complete feed due to the low inclusion rate of mineral ingredients in the total diet.
Table 1. AAFCO published maximum tolerable limits of heavy metals in complete feed and mineral ingredients.
| Mercury | Cadmium | Lead | Arsenic | |
| Maximum Tolerable Level in Complete Feed (ppm) | 0.2 | 0.5 | 10 | 30 |
| Labeling of Contaminant Level in a Mineral Ingredient Required Above (ppm)* | 2 | 2 | 42 | 42 |
| Use in Feed Prohibited as a Mineral Ingredient Above (ppm)* | 500 | 500 | 1000 | 1000 |
*This value represents the total ppm of all elements within the same group. For example, the level of mercury and cadmium combined cannot exceed 2 ppm in a mineral ingredient without proper labeling designating the level of contamination.
CFRP did not detect levels of heavy metals above the AAFCO guidelines in the 138 samples of mineral ingredients and premixes obtained from 2024 to date. Heavy metals are commonly detected in the samples, but typically below the tolerance level for complete feed. All detections have been well below the level at which the mineral ingredient or premix would require labeling to indicate the contaminant.