The reverse leakage current for this electrical device should be 500nA @ 68V.While operating, the maximum voltage - Zener (Nom) is reduced to 91VV.For its operation, maximum voltage - Forward (Vf) 1.2V @ 200mA is provided.
BZG05B91-HM3-18 Features
reverse leakage current of 500nA @ 68V 500nA @ 68V is the maximum voltage (Tol)
BZG05B91-HM3-18 Applications
There are a lot of Vishay Semiconductor Diodes Division BZG05B91-HM3-18 applications of zener single diodes.