Organic is the best,but fresh produce soaked in a produce detergant is second best.carrots and beets are mainly underground and has less residual toxins.Avoid spinach,celery,they are heavely sprayed with toxins.As with all things do the best you can relavant to availability and budget conserns.Hopefully organic demand will increase to the point where it is plentifull and relativaly cheap.You can get produce or vegatable wash at a healthfood store.Good luck and happy juicing!!