Preamble (random babbling, ignore):
I just found myself fighting against an Infernal Mobs skeleton which imposed a Wither effect onto me and killed me quite quickly. After resurrecting I noticed that, because I was priorly working on my reactor automation, I wasn't in my armor, but instead the HazMat suit, so my quick demise probably was warranted ... however ...
Suggestion:
I started thinking: My HazMat suit protects me from radiation - the smallest particles (and I will ignore that irl HazMat suits work differently and stick to the ingame mechanics) ... so why did I get a withering effect? Which once again got me thinking that of course I was shot at with arrows and took damage - but so did the suit, and even a damages HazMat suit still protects from radiation.
So in the end in my opinion for whatever low physical protection a HazMat offers, it should not only protect against the radiation debuff, but also against at least against the poison and wither effect, because if radioactive particles cannot reach you, then poisonous agents should not be able to, either.
The list of effects could probably be extended even more, but one that I thought of, Fire/Heat protection, I would clearly dismiss. Being a member of a catastrophy relief unit I know that heat exchange (or rather the lack thereof) is actually a danger not to be underestimated when being in protective gear.
So as a secondary thought, while I think the HazMat should protect from more than just radiation, maybe (if there is a way to actually implement it) it would make sense to also *increase* the damage taken from different sources. "Take no poison damage while suffering twice the fire damage."
Mhh ... maybe even making it impossible to take off the HazMat while on fire? So many possibilities. 