In an attempt to counter complaints that a certain pesticide is potentially hazardous to humans if absorbed into edible plants, the pesticide manufacturer has advertised that “ounce for ounce, the active ingredient in this pesticide is less toxic than the active ingredient in mouthwash.”
Conclusion (implied)
The pesticide isn't hazardous to humans if absorbed into edible plants.
Evidence
Ounce for ounce, the active ingredient in this pesticide is less toxic than the active ingredient in mouthwash.
Evaluate
We know that the pesticide's active ingredient is less toxic than the active ingredient in mouthwash.
However, this doesn't inherently mean using the pesticide is safe. Maybe mouthwash is hazardous to humans. Maybe the pesticide has many more ounces of that toxic ingredient than mouthwash does. Maybe a human would swallow much more of the pesticide by eating affected plants than a human would ever swallow mouthwash.
Goal
We need an answer that helps us argue that even though the pesticide's active ingredient is less toxic mouthwash's, the pesticide still isn't safe and could be bad for humans if they ate it.