That's the part I'm not clear about. Would someone need both inhalation and contact protection in order to get any protection?
There's no rules for partial bonuses, and the question I recently find myself asking when this topic comes up - how would you treat drugs with multiple vectors? Deepweed has an obvious modern day equivalent, and while I'm not well versed on the methods of recreational use, I
don't think you can smoke and eat a single dose
at the same time.
There are numerous delivery methods for drugs and toxins. To limit potential delivery to the available vectors, and operating vector to the delivery in use, may not always make sense - but it's a lot lighter on house rules.
*gah ... thread necromancy strikes again!*