  We study the relation between gaseous absorbing column density (N$_{\rm H}$),
infrared colors and detectability of the broad lines in a large sample of
Seyfert 2 galaxies(Sy2s). We confirm that Sy2s without polarized broad lines
tend to have cooler 60$\mu$m/25$\mu$m colors; this correlation was previously
ascribed to the effect of obscuration towards the nuclear region.
  We find some evidence that Sy2s without polarized broad lines have larger
absorbing column density (N$_{\rm H}$) and that a fraction of them are
characterized by dust lanes crossing their nuclei.
  However, we find that the IR colors do not correlate with N$_{\rm H}$, in
disagreement with the obscuration scenario.
  Also, Sy2s without polarized broad lines follow the same radio-FIR relation
as normal and starburst galaxies, at variance with Sy2s with polarized broad
lines. These results indicate that the lack of broad lines in the polarized
spectrum of Sy2s is mostly due to the contribution/dilution from the host
galaxy or from a circumnuclear starburst, though at a lower extent the
obscuration toward the nuclear region also plays a role.
