Halon was a great gas. It’s heavy and works to displace oxygen without leaving residue. Perfect for electronics and the like. The downside is that it’s very destructive to the ozone layer. That’s why it went away. It’s not actually really harmful to humans, other than it can suffocate you by displacing O2. 

Ryan/// ~sigh~ I blew up another bowl. Moke told me "I made the inside bigger than the outside".