An electrical device like this requires a reverse leakage current of 500nA @ 33V.While the device is operating, the maximum voltage - Zener (Nom) is reduced to 43V.For operation, diode reaches 1.2V @ 200mA at the maximum voltage - Forward (Vf).
BZG05B43-HM3-18 Features
reverse leakage current of 500nA @ 33V 500nA @ 33V is the maximum voltage (Tol)
BZG05B43-HM3-18 Applications
There are a lot of Vishay Semiconductor Diodes Division BZG05B43-HM3-18 applications of zener single diodes.