Unfortunately my exposures seem to depend on accidentally getting products on my face. On the one hand, in theory you could prevent this by being careful about touching your face, but it's obviously not foolproof... on the other hand, Bath Products are Everywhere and it's hard to predict.

This time it was cuticle oil, which doesn't smell offensive in general and which I've used several times before on my hands... and then I guess there was some extra on my fingertips that I was unaware had not fully absorbed when I went to bed and I accidentally touched my face in my sleep. - Since I didn't even suspect the product previously, it seems like the logical conclusion is to be safe I should never put anything with any scent on my hands, but I am actually already fairly careful about that and usually buy expensive scent-and-color-free hypoallergenic moisturizer from the state-licensed pharmacies.

Hence if I wanted to take preventive medicine I'd basically just have to take it all the time I think. :|