Hmm, tough question but if you don't have a Mac how do you test? With a Mac you can test easily on Windows and Linux. But if you just use Windows, then you need an alternate machine to test for Mac compatibility, you can dual boot into LInux.
Safari?
But that's testing. Your QA team (even if its a team of 1) should have access to some kind of Mac environment. That doesn't mean your devs need to use Macs.
Ideally, anyways.