Sulfur Hexafluoride

Adam Savage of Mythbusters shows what happens when you inhale sulfur hexafluoride, which “is a colorless, odorless, non-toxic and non-flammable gas.” Video after the break.

Another effect is the gas’s ability to alter vocal sound waves. The gas can be inhaled in a small, safe amount and cause the breather’s voice to sound very deep.

[via Wiki]