I know you’re probably thinking: but how toxic is the resulting worm waste? Well, according to Wu, the waste is safe to use as soil on crops. The other by-product of the process is carbon dioxide, which is the case for anything the meal worms eat. And the plastic-eating worms didn’t appear to be less healthy than worms eating a more natural diet.And the plastic-eating worms didn’t appear to be less healthy than worms eating a more natural diet.