I've cleaned in rooms that are 40 feet from my kitchen, only to find a thin covering of petal dust or red color on everything. This isn't good, because you just know that you're inhaling a lot of that stuff.
The best thing to do would be to work outdoors, but sometimes that isn't possible. In cases where you don't have an exhaust fan and you need to work inside, you should at least try to contain the overspray. This is my high-tech spray catcher, i.e. a large cardboard box.
I keep this flat in a corner of my office until I need it, then I set it up on the counter. I wear a face mask to keep even more of the spray out of my nose, and put whatever it is I'm working on inside the box. This really does help to keep everything in one place and out of your house, but definitely go outside to do anything spray or dusting-related if oyu can.
Kara Buntin owns A Cake To Remember LLC in Richmond VA, and cake supplies online at www.acaketoremember.com and www.acaketoremember.etsy.com