  We investigate the relation between essential divisors and F-blowups, in
particular, address the problem whether all essential divisors appear on the
$e$-th F-blowup for large enough $e$. Focusing on the case of normal affine
toric varieties, we establish a simple sufficient condition for a divisor over
the given toric variety to appear on the normalized limit F-blowup as a prime
divisor. As a corollary, we show that if a normal toric variety has a crepant
resolution, then the above problem has a positive answer, provided that we use
the notion of essential divisors in the sense of Bouvier and
Gonzalez-Sprinberg. We also provide an example of toric threefold singularities
for which a non-essential divisor appears on an F-blowup.
