In my apartment building they come in once a month to spray. The guy wears an oxygen mask. I would never let him into my apartment in a million years. But plenty of other people in my building do. At least most poisonous sprays here have to have awful smelling chemicals added to them so that you can tell you're inhaling something super toxic. Sometimes I can smell those things when I go out of my apartment. It's a faint smell, most people probably don't notice it too much if their whole apartment has been sprayed. But at least I can tell.
I never had to use sprays like that. When I had roaches 2 years ago, I put some baits so that the roaches would eat that, the poison is strong enough that when roaches cannibalize on dead roaches' bodies, they die too. That got rid of them within a few months. Once when I was living in another apartment, I had an ant problem because the ants would eat a kind of silicon sealing that was used on the balcony to keep it from leaking rainwater (it was a very large balcony on the top floor of the building). I used an ant spray that you just put in one tiny spot where the ant trail is, any spot where the main trail is. I chose a spot in the balcony that was far removed from anywhere I would be (or anybody else in the apartment building). And they all disappeared within a couple days. I'm guessing they all died, but maybe they just chose to stop coming into my balcony.
Now the only problem I have is with fruit flies and mosquitoes, but I'm trying to deal with the fruit flies by using baits made of a mixture of apple cider vinegar and detergents. The baits seem to be working so far, but it's only been a few days and I only put two baits in my whole apartment which isn't small. Maybe I will need to add more. And the mosquitoes are not too bad, I can tolerate them for now. I've heard some essential oils can help. Maybe I'll try those.