Milorganite® Safety

A scientist testing in a labatory.

Milorganite is produced with your safety in mind every single day. It complies with all applicable federal and state requirements and can be used with confidence for all of your fertilizing needs, including lawns, trees, shrubs, flowers, and vegetables.

It meets stringent criteria imposed on any fertilizer product for health, safety and the environment and is more heavily regulated by the United States Environmental Protection Agency (EPA) than synthetic fertilizers. Milorganite has consistently met the EPA’s Exceptional Quality criteria since 1993, when the guidelines were created.

Daily Testing for EPA and State Standards

Milorganite is analyzed for at least 20 parameters every day to comply with all applicable safety guidelines. Routine analysis is also conducted to test for numerous other pollutants and pathogens. For additional information, you can refer to Milorganite’s Safety Data Sheet.

The Truth About Metals

Metals are not all bad. Some metals are micronutrients and are necessary in small amounts for plants to grow and reproduce, including copper and zinc, which naturally occur in the environment. For a product like Milorganite, federal and state regulations have established limits for metals to protect public health and the environment. Milorganite contains metals at levels found safe by EPA when Milorganite is used as directed.

Metals - EPA Limits and Milorganite Averages
Metals and Micronutrients EPA Exceptional Quality Limit 2020 Milorganite Average
Arsenic 41 mg/kg 18 mg/kg
Cadmium 39 mg/kg 0.97 mg/kg
Chromium No limit 170 mg/kg
Copper* 1,500 mg/kg 230 mg/kg
Lead 300 mg/kg 30 mg/kg
Mercury 17 mg/kg 0.21 mg/kg
Molybdenum* 75 mg/kg 8.4 mg/kg
Nickel 420 mg/kg 23 mg/kg
Selenium 100 mg/kg 4.4 mg/kg
Zinc* 2,800 mg/kg 380 mg/kg

*Essential micronutrients

Heat Drying Kills Pathogens

Milorganite is heat-dried in large-scale, bus-sized rotary dryers that operate at 900–1200°F which heats the Milorganite to an internal temperature of 176°F. The extreme heat and dryness kill pathogens. Here’s a video on how Milorganite is produced. You can see the dryers for yourself.

Children and Pets

Milorganite is safe for your children and pets when used as directed and stored out of their reach. Milorganite is composed of organic matter and nutrients and contains no added pesticides or herbicides.

Non-Leaching Phosphorous

Phosphorus in runoff is a significant pollution problem.  Excess phosphorus causes algae blooms, fish kills, and odors. Plants, including grass, need phosphorus, as it contributes to important functions such as root development and growth. The phosphorus in Milorganite is slow-release, reducing the risk that phosphorus will leach from soils into surface or groundwater. In contrast, other fertilizers often contain quick-release phosphorus that is more likely to leach.  

Micro-impurities: Pharmaceuticals and Personal Care Products

In modern society, it’s inevitable that trace amounts of pharmaceuticals and personal care products will be present in wastewater. Although detectable, concentrations of these compounds are extremely low in Milorganite.

From water reclamation and Milorganite production to harvest and consumption, it’s a long pathway for these micro-impurities to reach humans. The risk they pose to people and the environment is extremely low and is reduced at every step along the way. Milorganite is a leader in investigating the risk caused by these compounds.

One study found that Triclosan, a commonly used anti-bacterial, anti-fungal agent used in a range of products from soap to toothpaste, was detected at very low levels in vegetables fertilized with Milorganite, with corn having the highest concentration. A 154-pound person could eat up to 1,249 lbs of this corn daily without any adverse effect, indicating that the risk of Triclosan exposure from Milorganite is extremely low.

Per- and polyfluoroalkyl substances (PFAS) Chemicals

The PFAS issue in biosolids fertilizer is a relatively new issue, and there is no clear indication that Milorganite fertilizer has a PFAS build-up that need’s remediation. Experience has shown PFAS concentrations in biosolids vary significantly depending upon local conditions, such as the type of water supply, the presence of fire suppression training sites, and industries that manufacture or use PFAS. 

For Milorganite fertilizer, local conditions that contribute to the production of our product favor low concentrations. In fact, PFAS sampling for Maine, concentrations for two of the three analyzed compounds were below the level of detection and the third was slightly above the level of detection, confirming minimal PFAS risk.

To understand and find solutions to the PFAS problem, Milorganite fertilizer supports (1) research into the fate of and risk from the PFAS that already exist in commerce and the environment and (2) restrictions on the continuing production and use of these chemicals. The entire water reclamation community is engaged with these issues. No individual producer of biosolids can address these issues alone. Please consider contacting your legislators to support action on these issues.   


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