- "Some operations are considered hazardous even for a fully armored Spartan"
- — Description of the HAZOP helmet.
There are three variants of the HAZOP helmet in Halo: Reach. These variants include the base model, costing 7,000 cR, a helmet with the CBRN/HUL attachment that costs 2,000 cR, and a helmet with the CNM-I attachment that costs 1,000 cR. The HAZOP armor also includes shoulder pieces, which costs 500 cR each.
The HAZOP helmet returns in Halo 4 for Spartan IVs to use during combat simulations aboard the UNSC Infinity. The Halo 4 Limited Edition includes several skins such as forest camo for the HAZOP armor system. The Forest skin can also be obtained by pre-ordering the game from Gamestop.
- The Halo 4 HAZOP helmet looks radically different with a T shaped visor and protrusions on the chin like the EOD helmet.