I don't think smelling it would be harmful (but then I didn't think eating it was harmful either!).

I don't think we react to the smell... ds is pretty super-sensitive (our canary in the coalmine - so to speak) and he doesn't react if we go into a bakery area or anything... but if we spend time in a gluten household and he touches a lot of stuff... esp. the kitchen table it seems... he's sick afterward. Kids do a lot of hand-to-face touching... esp. allergic kids because they rub their noses a lot. I've tried to train mine to rub with their arms and not their little fists/hands and their generally good about it but sometimes they forget.