Food safe compost use discussed in proposed Food Safety Modernization Act rules

From an agronomic perspective, compost is unmatched as a soil builder and can greatly contribute to overall plant and soil health. The new proposed produce safety rule is fairly prescriptive as to its creation, storage and preharvest application.

From an agronomic perspective, compost is a soil builder and can significantly contribute to overall plant and soil health. From a food safety perspective, improperly prepared compost from animal manure, animal mortality or post-consumer food residue used in growing fresh produce can be a hazard. Proper composting of animal derived materials is essential to ensure a reduced risk of contamination. The newly released produce rule as part of the Food Safety Modernization Act is fairly proscriptive as to what constitutes adequate composting under the rule.

The proposed produce safety rule as part of the Food safety Modernization Act proposes that all compost with animal derived materials (e.g., manure, mortalities, table scraps, etc.) must be either statically composted to at least 131 degrees Fahrenheit for three days then cured and insulated, or aerobically composted to at least 131 F for 15 days and turned at least five times, then cured and insulated. This is reasonably consistent with current food safety recommendations from the National GAPs Program of having a pile reach between 130 F and 160 F for five to 15 days.

The produce rule requires that properly composted material with animal derived materials be given a preharvest interval of 45 days after application when it is applied in a way that minimizes crop contact. If the compost with animal derived materials is not properly made, the rule states that it must be treated like raw manure. The preharvest application window for raw manure under the proposed produce rule is nine months prior to harvest.

As of Feb. 1, 2013, these compost guidelines are proposed and not final. The final rule regarding compost use in fresh produce may vary, so it is important to stay aware of what is finally decided. You can also comment on the proposed guidelines.

If you have specific questions about food safety aspects of compost use or have difficulty tailoring GAPs to your farm, contact the Agrifood Safety Work Group at gaps@msu.edu or 517-788-4292.

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