If you check HM customs site under 4.2.1 exempt producers /users ,If you produce or youse less than 2,500L of * any biofuel or * any other fuel substitute or aditive , this takes in wast veg and new under biomas ,you need to keep records as discribed in 4.9.1 ,this only aplies to private youse. will just add had my van checked by HM customes on a spot check on fuel ,was runing 50/50 veg at the time and there was problem as long as it was private youse .