I dumped DE in with my sand and dirt and there have been no issues. Several pounds at a time. People seem to be afraid of DE, but I dust my girls weekly, the dust flies and I breathe it and they breathe it also. I have never experienced even 1 problems, this is the food grade DE. It is not poisonous and people not only eat DE, but breathe in far worse just sitting in traffic. Just saying... I certainly wouldn't put it in a bag and hyperventilate. But, seriously I haven't experienced any problems and it really helps with lice and fleas, my girls don't have them, since I started using DE every few weeks, plus putting it in their dust bath area. We built a sand box, they wouldn't use it with just sand and DE, so we dumped dirt on top, now they love it.Don't use too much DE. It can be harmful in large amounts.