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I don't know about artificial flavours but "natural flavors" seem
pretty risky to me.  In the United States, "natural flavor" is
defined in the Code of Federal Regulations and seems like it could be
just about anything.  (see definition below)  I have made many phone
calls to manufacturers to inquire the composition/ingredients of
natural flavors and have never been told ("it's a trade secret") but
have often been told that specific flavors are gluten free -- which I
still have some skepticism with since I've seen "gluten free" defined
in ways that I wouldn't define it.  Anyway, here's the legal
definition:

According to 21 C.F.R. S 101,22(a)(3):
"[t]he terns 'natural flavor' or 'natural flavoring' means the
essential oil, oleoresin, essence or extractive, protein hydrolysate,
distillate, or any product of roasting, heating or enzymolysis, which
contains the flavoring constituents derived from a spice, fruit or
fruit juice, vegetable or vegetable juice, edible yeast, herb, bark,
bud, root, leaf or similar plant material, meat, seafood, poultry,
eggs, dairy products, or fermentation products thereof. whose
significant function in food is flavoring rather than nutritional."


--Carl