  Slowly Pulsating B and $\beta$ Cephei are $\kappa$ mechanism driven pulsating
B stars. That $\kappa$ mechanism works since a peak in the opacity due to a
high number of atomic transitions from iron-group elements occurs in the area
of $\log T \approx 5.3$. Theoretical results predict very few SPBs and no
$\beta$ Cep to be encountered in low metallicity environments such as the Small
Magellanic Cloud. However recent variability surveys of B stars in the SMC
reported the detection of a significant number of SPB and $\beta$ Cep
candidates. Though the iron content plays a major role in the excitation of
$\beta$ Cep and SPB pulsations, the chemical mixture representative of the SMC
B stars such as recently derived does not leave room for a significant increase
of the iron abundance in these stars. Whilst abundance of iron-group elements
seems reliable, is the opacity in the iron-group elements bump underestimated?
We determine how the opacity profile in B-type stars should change to excite
SPB and $\beta$ Cep pulsations in early-type stars of the SMC.
