  Narrow-line Seyfert 1 galaxies (NLSy1) are intriguing due to their extreme
continuum and emission line properties which are not yet well understood. This
paper is motivated by the recent suggestion that NLSy1 galaxies might be young
active galactic nuclei (AGNs) and that they may have supersolar metal
abundances. We have examined the stability of broad emission line region (BLR)
clouds under isobaric perturbation and its dependence on gas metal abundances.
We show that supersolar metallicity increases the range where multiple phases
in pressure balance may exist. This is particularly important for NLSy1s with
steep X-ray spectra where it delays the trend of hindrance of a multi-phase
equilibrium. Finally, the role of warm absorbers in the context of this
scenario is assessed.
