Measuring POEA, a Surfactant Mixture in Herbicide Formulations

Science Center Objects

POEA (polyoxyethylene tallow amine) is a surfactant with known toxic effects on aquatic organisms. POEA was added to the original formulation of the herbicide glyphosate to aid in its application and effectiveness at controlling weeds. U.S. Geological Survey (USGS) scientists developing methods to measure POEA in the environment have shown that it’s a complex and variable mixture of related compounds, and that POEA is still a common additive in several newer agricultural and household glyphosate formulations.

USGS scientists used advanced analytical equipment to investigate the composition of POEA (polyoxyethylene tallow amine)

USGS scientists used advanced analytical equipment to investigate the composition of POEA (polyoxyethylene tallow amine).

(Credit: Daniel L. Tush, USGS. Public domain.)

Since glyphosate is one of the most widely used pesticides in the United States, the findings could indicate that POEA may be widely available for transport into surface water and groundwater. Such additives in pesticide formulations are commonly called "inert" ingredients or adjuvants, and little is known about these ingredients and their occurrence and transport in, and effects on, the environment. This USGS study is the first step in investigating the environmental fate and effects of POEA in herbicide applications.

This study was funded by the USGS Toxic Substances Hydrology Program.