Cyanazine is an herbicide that was mainly used on corn crops in Minnesota from the early 1970s through the 1990s. Cyanazine use stopped in 2002 when the registration of this pesticide was voluntarily cancelled. Cyanazine breaks down in the environment into different chemicals. Some of the breakdown products of cyanazine have been detected in surface water and groundwater in Minnesota, including private drinking water wells. Consuming water with concentrations of total cyanazine (cyanazine plus its breakdown products) above the Health Risk Limit (HRL), set by the Minnesota Department of Health (MDH) at 1 microgram per liter (µg/L) or 1 part per billion (ppb), may present a health risk when consumed over long periods of time. Consuming water with total cyanazine concentrations above 3 µg/L may pose a risk if consumed in shorter periods of time. More information on the risks associated with cyanazine and its breakdown products is available on the MDH website.
Cyanazine is an herbicide that was mainly used on corn crops in Minnesota from the early 1970s through the 1990s. Cyanazine use stopped in 2002 when the registration of this pesticide was voluntarily cancelled. Cyanazine breaks down in the environment into different chemicals. Some of the breakdown products of cyanazine have been detected in surface water and groundwater in Minnesota, including private drinking water wells. Consuming water with concentrations of total cyanazine (cyanazine plus its breakdown products) above the Health Risk Limit (HRL), set by the Minnesota Department of Health (MDH) at 1 microgram per liter (µg/L) or 1 part per billion (ppb), may present a health risk when consumed over long periods of time. Consuming water with total cyanazine concentrations above 3 µg/L may pose a risk if consumed in shorter periods of time. More information on the risks associated with cyanazine and its breakdown products is available on the MDH website.
The MDA is responsible for monitoring groundwater and surface water for pesticides and fertilizers. They also provide support to other agencies that are interested in monitoring for pesticides. As described above, the MDH is responsible for developing health-based reference values for drinking water and monitoring public water supplies. The Minnesota Pollution Control Agency (MPCA) is responsible for developing surface water regulatory standards and monitoring surface waters for non-agricultural chemicals. There are no surface water standards or reference values for the cyanazine breakdown products.
The MDA is responsible for monitoring groundwater and surface water for pesticides and fertilizers. They also provide support to other agencies that are interested in monitoring for pesticides. As described above, the MDH is responsible for developing health-based reference values for drinking water and monitoring public water supplies. The Minnesota Pollution Control Agency (MPCA) is responsible for developing surface water regulatory standards and monitoring surface waters for non-agricultural chemicals. There are no surface water standards or reference values for the cyanazine breakdown products.
Prior to 2019, only one federal research laboratory in the nation was capable of testing for cyanazine breakdown products. In early 2019, the MDA laboratory and a private laboratory under a contract with the MDA (Weck Labs) were able to develop a method to detect and measure cyanazine breakdown products in water. Both the MDA and the contract laboratory have been conducting analysis for cyanazine breakdown products in water samples since March 2019. Starting in 2021, another private lab (Eurofins Eaton Analytical) is now capable of analyzing for the cyanazine breakdown products, bringing the total private labs to two.
