Richard said:
These are excellent and spot-on questions, but not easy ones to answer in any succinct way. Even when I teach a 3 hour class on these topics we only scratch the surface!
When would selling your own herbal teas require nutrition or supplement facts labels, either locally or online?
Basically, the FDA GMPs including labeling requirements would come into play if covered by DSHEA - with a tea blend this would generally happen if any health claims are made in association with the tea such as a structure-function claim. Otherwise, herbal teas can fall under the legal category of "food" rather than "dietary supplement", which would not require that but would require compliance with any local (county, state) health codes for selling food, including potential permits. Note that you would still likely need to list ingredients and possibly other things on the label for selling as a food product.
When would a commercial kitchen or other manufacturing facility be required (versus making it in your own kitchen)?
So..this can vary widely (wildly?) from state to state. Like I wrote above, you need to look into local (state and county) regs for getting the appropriate permit(s). In some states (maybe most?) you can potentially do this from a home kitchen - though the permitted sales venues may be more limited. If you trigger DSHEA and dietary supplement regulations with FDA oversight, using your own kitchen would never be enough to be fully legally compliant, unless you have made your home kitchen compliant with the cGMPs, which is next to impossible!
*Note that I am giving you a very abbreviated answer, and also a literal answer as to what the law says, which is different (can be very different) from what a lot of people actually do!
I would recommend familiarizing yourself with drug claim language and structure/function claim language, to avoid it, if you want to keep things simpler for yourself in selling herbal teas and keeping it in the legal category of "food". And contacting your local (county) health dept as well as looking into your particular state's regs, is a good start.
Once you go beyond teas into tinctures etc. it is automatically covered by DSHEA, though topicals like salves etc. can be legally considered cosmetics if you avoid the language that triggers DSHEA, as above...