Are your other department members (a) native English speakers, but not British, or (b) non-native English speakers? In my experience, there is a huge difference. I am a native English speaker. When speaking with (a) but from a different region, you can usually speak in your normal style, but don't use too much slang. With (b), I remove any slang and choose my words much more carefully. My goal is to communicate well, even if I need to adapt my style.