Common products containing glyphosate include different versions of Roundup, Sharpshooter Plus and Touchdown Total. First synthesized in 1970 by chemists working for Monsanto, glyphosate is a broad-spectrum herbicide that kills most broadleaf annual weeds and some grasses. It is one of the most commonly used herbicides in the world, and it is popular among farmers and recreational gardeners.
The amount of glyphosate in various commercial products varies widely, which means that users must be sure to follow the application directions on the label. The U.S. Environmental Protection Agency lists glyphosate as Toxicity Class III, which is the second safest designation. While human injuries are rare, some people do experience chemical burns upon exposure. When inhaled, the mist causes a burning sensation in the nose, mouth and lungs in most people. It can be dangerous if significant quantities are ingested.
Some plants are not affected by glyphosate. In some cases, this is the result of natural adaptations, but scientists have also purposefully created some plant strains that are immune to it. This allows farmers to treat their entire farm without fear that the herbicide may kill their crops. Soy and corn were the first two crops to be designed in such a way.