|Glyphosate is marketed as Roundup. Photo Creative Commons|
This reputation for safety is based on facts. In the environment, measurements have shown that glyphosate quickly disappears: it can be degraded by soil microbes and sunlight, washed away, or immobilised in the soil. In animals, it has low toxicity because animals don't have the metabolic pathway that glyphosate interferes with in plants, and the herbicide rapidly passes unchanged through the body to be excreted harmlessly in urine. All true, and all based on science.
However, there's another side to these facts.