Duke Study Finds CF4 Gas Switch Cuts Pig Dive Deaths to 0% From Over 80%

2 articles · Updated · Livescience.com · Aug 13

40 pigs in simulated 200-foot dives survived when switched from heliox to oxygen-CF4 for the final 10 minutes, while more than 80% of pigs breathing heliox throughout died within three hours.
The switch works by replacing some helium in tissues with carbon tetrafluoride, a larger, less soluble inert gas that leaves less total inert gas to form dangerous bubbles during ascent.
Researchers also saw milder decompression-sickness signs in the CF4 group, including fewer heart gas embolisms and less walking impairment after the hour-long dives.
Duke's team said the approach is not ready to become standard for human divers, and CF4's cost would likely confine any use to commercial or military diving rather than recreational diving.