Much of the seed planted this year will have been treated with a fungicide, insecticide and/or nematicide. As when working with any pesticide, care should be taken when handling treated seed so that exposure to the handler, non-target organisms, and the environment is reduced or prevented as much as possible.
Exposure to the Handler: Although growers may be more familiar with checking an herbicide or insecticide label for the appropriate personal protective equipment (PPE) to wear when handling a product, every bag of treated seed will also list the proper PPE to be worn when handling the treated seed. Wearing the appropriate PPE will help reduce or prevent pesticide exposure when working with treated seed.
The PPE to be worn when handling treated seed will typically include a long-sleeve shirt, long pants, shoes, socks, and chemical-resistant gloves. Unless the seed bag label specifies the type of chemical-resistant gloves to be worn, there are several types a handler can choose from, varying in flexibility and durability. Note that leather or cloth gloves are not chemically resistant! Cloth and leather gloves can soak up pesticide residues and result in pesticide exposure each time they are worn.
Handlers of treated seed should also take care to limit exposure to any dust when opening or emptying out seed bags.
Exposure to non-target organisms and the environment: Treated seed is not to be used for food, feed or oil processing, and care must be taken to not contaminate grain that will be going into the food or feed market. There is ZERO tolerance for treated seed in the export market, meaning that a single seed could result in the rejection of an entire load.
Treated seed should also not be left on the ground surface as some products can be hazardous to birds and mammals, or may be toxic to fish and aquatic invertebrates. Any seed spills should be covered or cleaned up as soon as possible.
A number of products are also toxic to bees and pollinators, so care should be taken to minimize dust as much as possible when filling and emptying out planters. Avoid conducting these tasks near flowering plants where bees and pollinators may be foraging.
Disposal of leftover treated seed: The best and most preferred option is to plant out any leftover treated seed on fallow ground or an unused parcel of land. Depending on the seed treatment, there may be restrictions on planting rate and depth. Seed burial may also be allowed, although care must be taken avoid burial next to water sources. Other potential options include disposal in an approved municipal landfill, use as a fuel source for a power plant or kiln, or incineration by a waste management facility.
For more information: Always be sure to check the seed bag label for specific details and restrictions about the product you are using. Depending on the product, there may also be rotational, plant-back, grazing or feeding restrictions. Further details can also be found on a University of Minnesota factsheet.
-By Lizabeth Stahl, U-M Extension crops educator