Short term exposure isn't much of an issue, unless you inhale or ingest it. (Simply playing with it isn't going to send out massive amounts of vapor; it's not s

Short term exposure isn't much of an issue, unless you inhale or ingest it. (Simply playing with it isn't going to send out massive amounts of vapor; it's not super volatile.) The real fear is that it seeps into a hard to clean place and provides a steady stream of vapor over a long time.... basically what the OP illustrated about his house. Previous generations had no qualms playing with it or lighting it on fire in science class. While it might not have been super healthy, we also don't have a generation of mad hatters.