Finding the safest pesticides

The U.S. Environmental Protection Agency goes to a lot of trouble to review thousands of toxicology test results in order to assess the environmental and human safety of each pesticide, as described here. So exactly why they would make it so difficult for us, the consumers, to find out which products they think are the safest, is unclear. But that is in fact what they have done.

The EPA system starts out clearly and simply — a DANGER signal word on the pesticide label means you're looking at a product deemed to be in Category I – the highest toxicity group. A WARNING on the label means the moderate toxicity of Category II products, and a CAUTION on the label means the low toxicity of Category III products. So far, so good. But for Category IV products — the safest of all the pesticides, the EPA allows manufacturers to either omit a signal word altogether, OR to use CAUTION on the label, which is the same signal word used for moderate toxicity products. The end result is that it's impossible to distinguish between Category III (low toxicity) and Category IV (very low toxicity) products based on the label.

To find the products with the lowest toxicity potential, you unfortunately have to do a bit of hunting. The best place to look is the MSDS (material data safety sheet) — also sometimes called the SDS (safety data sheet), which accompanies each shipment of pesticide. If you go to section 11 (toxicological information) of the sheet, it will show the results of the 6 toxicology tests that the EPA uses in their toxicity categorization system. By comparing those results against the scheme shown here, you should be able to determine whether the product is a Category IV or not. If the product exceeds Category IV standards in even one toxicity category, then it cannot be classified as Category IV.

This is much more awkward than it should be, and we hope that the EPA makes their system more transparent in the future. Until then, you'll have to delve. We have listed below a few of the Category IV products that are commonly used in turf.

• Insecticide: Conserve (spinosyn)
• Insecticide: Acelepryn (chlorantraniliprole)
• fungicide: Alude, and many other phosphonate or phosphite fungicides
• Herbicide: Tenacity (mesotrione)