Overview - Regulatory Framework
When herbicides are applied in agricultural situations, data on the sorption and degradation kinetics in soil are key parameters in the risk assessment. In non-agricultural situations the soil layer may be absent and application surfaces can include concrete, asphalt, gravel, other stones including railway ballast.
Sorption and degradation will be different to soil and other physico-chemical properties may be important in determining the fate of the applied herbicide e.g. photolysis, solubility, volatilisation. These application surfaces may have different degrees of sediment and organic material incorporated within them thus further influencing the fate of the herbicide. The processes and pathways which determine the entry of non-agricultural herbicides into surface and groundwaters are not well described however recent and current research is beginning to develop an understanding of fate and the resulting concentrations in water sources.