The maximum concentration of a chemical compound which can result when it is dissolved in water. If a substance is water soluble, it can very readily disperse through the environment.
Solubility is measured in mg/l of the pesticide in water at room temperature (20 or 25°C). It is generally the solubility of the pure (active ingredient) that is measured, not the formulated product.
The ability of a liquid or solid to mix with or dissolve in water.