  We propose a $\mathbb{Z}_{2}$ classification of Abelian time-reversal
fractional topological insulators in terms of the composite fermions picture.
We consider the standard toy model where spin up and down electrons are
subjected to opposite magnetic fields and only electrons of the same spin
interact via a repulsive force. By applying the composite fermions approach to
this time-reversal symmetric system, we are able to obtain a hierarchy of
topological insulators with spin Hall conductance
$\sigma_{s}=\frac{e}{2\pi}\frac{p}{2mp+1} $, being $p,m \in\mathbb{N}$. They
show stable edge states only for odd $p$, as a direct consequence of the
Kramer's theorem.
