Nothing is safe in that range - that's why it's unrealistic. The cast iron would decompose, shatter, and light a commercial kitchen on fire, let alone a residential tinder box.
You all may be arguing against a strawman. A completely hypothetical one, at that.
The actual danger temp, 260c / 500f, is trivially achievable on most home cooking equipment.
And even if the danger temp were 2,000 degrees, there would still be the major dangers from manufacturing and the associated pollution, as has been noted.
