We don't offer opinions on safety here, due to liability.
If you intend to spray a very large area of your property with insecticide, you should first inquire whether you are allowed to do that where you live. My opinion is that if you are intending to treat a very large area, you should contact an expert, because they will know what laws and ordinances apply, and will also know what is an appropriate insecticide that is safe and effective, what concentration to use, how much to spray, and so forth. Generally professional pest control is not very expensive.