I work in an environment where I can not wear my yarmulka. I know you can not make a bracha without a yarmulka, but can you eat without one? (ie, make a bracha with a yarmulka then take it off) Are there sources?

There are two opinions on the matter: The Gr"a writes that one can eat without covering ones head. On the other hand the Mishna Berura brings the Taz who Paskens that it utterly forbidden to not cover ones head while eating. The Mishna Berura concludes that one must cover ones head. I would suggest wearing either a wig or a hat while eating and thus solving the problem elegantly. If there is no other solution you can eat bareheaded. Rabbi Yitzchak Grinblat