Shake hands and say “Hello.”
I know what you’re thinking — “But I work with these people all the time, and they know me already.”
So? Isn’t this a special occasion? Aren’t you happy you’re getting the chance to get together to learn about a vital safety and health topic that will have an impact on everyone’s life?
When I was a safety supervisor for Stone and Webster, I hosted a safety meeting every Wednesday. All the employees on-site knew me, yet I still walked around and said hello before I started every meeting. 
Even if you don’t shake hands, go around the room and talk with as many audience members as you can. It’s fine if you don’t get to everybody. People you don’t greet will see that you are making an effort get personal in a friendly way. Spending time with your audience before you start does two things:
1) Helps loosen you up–you’ll be more relaxed and ready to go once you “officially” start the meeting.
2) Shows you care. Your audience will get the signal that you care about them as individuals–that this is for them, and you’re not just fulfilling an obligation to hold a scheduled safety meeting. Unless it’s impossible due to logistics, even now as a professional speaker, I always go around and talk with folks in my audience. Believe me; it makes a difference.
