Hmm, that's a much tighter estimate. (The page is poorly written (and frankly comes across as condescending(telling people that "exp" is some mathematical operation is not helpful) and poorly formatted. This is not good when cryonics already triggers some peoples' crank warning detectors) The math seems correct. That gives a much better bound for when chemical reactions will be an issue. It seems strongly then that my initial estimate that chemical reactions prevent kiloyear preservation is pretty wrong.