... resistant to hydrolysis in both acidic and alkaline media. Decomposed by sunlight. pKa 3.3 (24 ºC) bentazone-sodiumSolubility In water ... site. Mode of action Selective contact herbicide, absorbed mainly by the foliage, with very little translocation, but also absorbed ... in Rev. Environ. Contam. Toxicol., 137, 111-134). In sunlight, bentazone undergoes rapid degradation, ultimately to CO2. It has low ...