When my DS was just a few weeks old the nurse said I could give it to him really weak when he was having a hard time. I asked the midwife and she said it would be fine. I don't know if I would do it all the time myself, but times DS wouldn't relax I would.
Uhh, I thought it was perfectly safe all the time. I've been giving it to Darlene for about a month 1/2 now.
To sooth gas pains (more natural then the crap in the store) and then once she started teething (bought teething pellets now).
Dunno if it's a worry, but I was told chamomile usually has a bit of ragweed and that it can trigger allergies for those (who like myself) are allergic to ragweed. However, I can have chamomile tea without any reaction.