Once when I was in church i rushed to greet a young lady (one of my acquaintances) with a kiss. She drew back a little, but I paid no heed. Afterwards, I noticed large, suspicious sores around her mouth, and I really freaked out! I discussed my concerns with a saintly older woman in the parish, and she told me," Everything that happens in church is "safe". God's grace protects us and watches over everything that happens here. All will be well."
I wonder if a similar principle would apply to God's protection from the dangers of incense? Maybe I'm simply naive, but it's a just a thought.