HAZOP-class Mjolnir

"Some operations are considered hazardous even for a fully armored Spartan"

- Description of the HAZOP helmet.

The MJOLNIR Powered Assault Armor/HAZOP (Hazard Operability), is a variant of the Mark V MJOLNIR Powered Assault Armor.

There are three known variants of the HAZOP helmet in Halo: Reach. These variants include the base model, a helmet with the CBRN/HUL attachment, and a helmet with the CNM-I attachment.