You sprayed ROUND UP, for INSECTS???? Round up is a Herbicide, to kill insects you use an Insecticide. To answer the OP's original question, all of the chemicals are safe used properly, that's why they are approved by the EPA after millions in testing. Use no common sense and don't follow the label, you can kill most anything with them.
Use a qualified Commercial Applicator, who is Licensed and you are fine.
Good luck on your lawn,
Greg Pierce, CTP
Lawnmasters Lawn & Landscape