LD50 is a standard measurement of acute toxicity that is stated in milligrams (mg) of product per kilogram (kg) of body weight. An LD50 represents the individual dose required to kill 50 percent of a population of test animals (in this case, lab rats unless otherwise noted). As shown below, lower numbers show greater toxicity.
So, folks, we don't need to resort to Internet pseudoscience scare tactics about CHEMIKILLZ!!!. We have data and critical thinking skills.
Glyphosate 5,600
Acetic acid (vinegar) 3,310
Sodium chloride (table salt) 3,000
Some pesticides used in organic farming:
Rotenone 300-500 (human estimate)
Lime sulfur 820
Copper sulfate 30 - 472
Somehow, the organic foods marketing people and an army of mommybloggers have convinced many folks that glyphosate is evil poison, and at the same time that organic foods are produced without pesticides. Both are myths. Data obtained from real research and provided in the MSDS for these compounds shows that glyphosate has a low level of toxicity in humans; lower than salt, vinegar, and some pesticides used in organic farming.
Glyphosate is safe when used properly, and will not contaminate your well. Mix the 41% concentrate at a rate of 2.5 oz/gal. Add a squirt of dish detergent to act as a surfactant if there isn't one already listed on the container. Apply it during a bright day so it dries quickly on the plants that you desire to remove.