My reply was a little flippant so I’ll give you a more substantive response- I’m a tenants rights attorney. You consented to entry when you signed the lease with the provision that requires you to give them access. If you don’t they can seek to evict you but that’s a dramatic step and seems unlikely especially for a building that large. I also can’t imagine you’re the only one who wont or cant provide access during business hours (assuming that’s when they spray).