I would not use it, that much powder should not be inhaled and could cause breathing problems, it is only meant to be used in small amouts, not all over the place, if you want to disenfect the loft use a disenfectant spray and let dry. they sell products just for lofts, belgium white is one, so check out your suppliers list. natural clay cat litter can be used in spots that seem damp from droppings too.