Compare Toxicity in Lawn and Garden Chemicals

Guide helps compare common insecticides, herbicides and fungicides used in Iowa

April 12, 2019, 8:54 am | Mark Shour, Adam Thoms, Lina Rodriguez Salamanca

person reading chemical label.AMES, Iowa – With the spring growing season upon us, homeowners and gardeners may be considering the use of pesticides and other lawn and garden chemicals to control familiar pests.

While the goal is to control or eliminate the problem, these chemicals should be applied in a way that is safe for both the applicator and the environment. With that in mind, educators with Iowa State University Extension and Outreach have recently developed an important chart of the toxicity of common lawn, garden and ornamental chemicals used to control insects, weeds and pathogens in Iowa.

Found within the publication “Toxicity of Common Lawn, Garden, and Ornamental Pesticides in Iowa,” the chart compares the toxicity of nearly 60 insecticides, 38 herbicides and 37 fungicides in easy-to-understand terms.

“Finding the toxicity values for pesticide active ingredients can be a challenge, so we’ve streamlined the process in these tables,” said Mark Shour, entomology program specialist with ISU Extension and Outreach. “People concerned with the toxicity of a pesticide on pollinators can find this useful information before purchasing a product.”

The chart includes each chemical’s LD50 value (toxicity measurement), and signal words, ranging from “CAUTION” on slightly toxic insecticides, to “WARNING” on moderately toxic pesticide and “DANGER” on those that are highly toxic.

The chart also provides information related to bee toxicity, so that consumers can choose a product that is less toxic to bees, especially when applying the product to flowering plants.

The full publication can be found in the ISU Extension Store at

For more information, contact Mark Shour at 515-294-5963, or email him at

Photo credit: Read the label, by Jed Findlay, Iowa State University.

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