NEW : 1 million gallons of dispersants used in oil spill . Louisiana environmental group calls for halt to dispersant use , despite EPA findings . EPA says dispersant currently being used is less toxic than others . Agency making no recommendations until more tests complete .
NEW : 1.5 million gallons of dispersants used in battling spill . Louisiana environmental group calls for end to dispersant use , despite EPA findings . EPA says dispersant currently being used is less toxic than others . Agency making no recommendations until more tests conducted .