  A popular regime in the NMSSM parameter space involves a light CP-odd Higgs
$A_1$. This scenario has consequences for e.g. light singlino Dark Matter
annihilating in the $A_1$-funnel. In order to confront the pseudoscalar to
experimental limits such as flavour observables, Upsilon decays or Beam-Dump
experiments, it is necessary to control the interactions of this particle with
hadronic matter and derive the corresponding decays. The partonic description
cannot be relied upon for masses close to $m_{A_1}\sim1$GeV and we employ a
chiral lagrangian, then extended to a spectator model for somewhat larger
masses, to describe the interplay of the CP-odd Higgs with hadrons.
Interestingly, a mixing can develop between $A_1$ and neutral pseudoscalar
mesons, leading to substantial hadronic decays and a coupling of $A_1$ to the
chiral anomaly. Additionally, quartic $A_1$-meson couplings induce tri-meson
decays of the Higgs pseudoscalar. We investigate these effects and propose an
estimate of the Higgs widths for masses below $m_{A_1}\leq3$GeV. While we focus
on the case of the NMSSM, our results are applicable to a large class of
models.
