The root inhibition zone is created and maintained by the trifluralin released from the nodules. Consequently, the highest trifluralin concentration in the soil is at the plane of the barrier, with concentration levels diminishing as distance from the barrier increases. The concentration level effective for all roots measured is less than 7.6 ppm.
Plant species vary in resistance to trifluralin.
With a water solubility of 0.3 ppm, trifluralin does not present a significant leaching problem. Additionally, trifluralin has a high soil adsorption and short half life. Since only a minute amount of trifluralin is emitted from the Biobarrier nodules at any point in time, the hazard is minimized. The U.S. EPA does not require a pesticide applicator license to install Biobarrier.