SOURCE: http://www.collective-evolution.com/2016/08/23/scientists-discover-ingredient-within-monsantos-roundup-herbicide-that-suffocates-human-cells/
The inert ingredients in Roundup formulations are not inert. The proprietary mixtures available on the market could cause cell damage and even death at the residual levels commonly found on Roundup-treated crops, like soybeans, alfalfa, and corn.
One of the inert ingredients is polyethoxylated tallowamine, or POEA, which the study found to be more deadly to human embryonic, placental, and umbilical cord cells than the herbicide itself. Glyphosate, POEA, and all four Roundup formulations damaged all three cell types. Umbilical cord cells were especially sensitive to POEA, glyphosate became more harmful when combined with POEA, and POEA alone was the deadliest to cells in comparison to glyphosate.