Season 6 Episode 4
In the cold open, Pam asks her coworkers if they would mind being more sensitive of smells due to her pregnancy related easily upset stomach. Dwight takes offense to this and decides to continue peeling and eating boiled eggs at his desk.
Pam vomits into her garbage can. Andy then vomits having witnessed Pam. This causes Meredith to vomit followed by Erin and then Angela.
This marks a huge moment in my journey. This is a Network show vomiting in 2009. There are previous episodes where people vomit, but they are off-screen.