Easy! I was interested in the Sticky Bricks last year. As you know I have the most insane allergies and am ultra sensitive to trillions of substances others have no reaction to. I am especially sensitive to bad, man made, chemical, toxic unnatural shit. Like cigiarettes for example. I became so allergic to tobacco smoke in 2005 I had to avoid it ever since, I really can't go in a house where there is smoke, or stand near people smoking outdoors. However, ready rolled cigs are 100 × worse than rolling tobacco! Literally, so unnaturally toxic and poisonous. Not being judgemental, I firmly beleive that smoking cigiarettes is arguably the most insane thing anybody does regularly. Natural tobacco on the other hand, I can get, but sure a debate could be had on what place it holds in the ideal world. Anyway, just an example. I am a real mining canary for bad stuff. But I also react severely to many harmless things too. I can usually tell if it is just a harmless inconvenient reaction, or a case of toxic assault. But not always in every case obviously. So I wanted to try the Brick, but was unsure whether the butane would cause me any issues. So I did some trials with my dynavap quad torch through a bubbler. And sure enough, there was a major respiratory reaction. I used the cleanest butane going. Im not saying the the butane is harmful or toxic, but there was plenty of stuff there for me to react to at least. And that is my simple point! Thank you for listening, have a good day.