"A standard hazardous materials suit that protects against a full range of environmental hazards including radiation, fire, biochemical toxins, electricity, and EMP. Hazmat suits contain an integrated bacterial oxygen scrubber that degrades over time and thus should not be reused."
Unlike the other items of this type, HazMat suits can be useful to most players. Suits can usually be found near hazardous areas, and so do not need to be lugged around like the armor and camo do. Using these items instead of the corresponding augmentation, Environmental Resistance, allows the player to use the Aqualung augmentation, which is arguably more useful, as rebreathers are much rarer than hazmat suits.
Despite the description, hazmat suits do not protect from fire, electricity, or EMP, but do protect against tear gas.