hahabogus said:Since the heating duct is galvanized sheet steel....and
that is poisonous when heated too hot. I suggest more
research on the galvanized steel. I'd rather you proved me
wrong than You died. Perhaps uncoated stainless steel or
aluminum heating duct is available.
fwiw, this solar page has a technical explanation:
"Galvanized sheet metal may be used inside the oven if
desired. SBC temperatures are not high enough to disperse
zinc, which melts at 419 F (215
C). Temperatures near or above the melting point cause
some molecules to migrate and could pose a health
hazard. If making any design of solar cooker that
reaches near to the melting temperature avoid galvanized
metal inside an oven."
solarcooking.orgkerr.htmOpen ↗
on the other hand, this code of SC regulations says in the
metals section:
"Galvanized metal shall not be used for utensils or food-
contact surfaces of equipment that are used for beverages,
moist food, or acidic food."
(no mention of heat) and in the barbecue section:
"Pit grills, grates, and other supports shall be constructed
of smooth, easily cleanable, nonabsorbent, and non-toxic
material and shall be in sections that are easily removable
for cleaning. Expanded metal and cast iron grating are
recommended materials which can be cleaned and maintained.
Hog wire, chicken wire, hardware cloth, and similar
materials are permitted for single-use only and must be
discarded after each cooking period."
i'd think "Hog wire, chicken wire, hardware cloth" would
usually be galvanized.
scstatehouse.net61 25.htmOpen ↗
to the OP - maybe a way to find out would be to call your
local health department and ask them what they'd say about
galvanized metal in a restaurant's barbecue. safety is
their business.