My Oxygen Tank simply turned into Tethers in the form of an Oxygen Tank, making it no longer useful.
I was running around on Barren, checked my inventory because I was wondering why I was depleting on oxygen so quickly, and it turns out my Oxygen Tank turned into Tethers, but still looked like an Oxygen Tank. I've put a Gyazo screenshot at the bottom of this thread/topic.
Version / Build Number:
OS: Windows 10
CPU: Intel i7 6700K @ 4.00ghz
GPU: AMD RX 480
RAM: (x4) 4 GB DDR4
Drive: Samsung SSD 850 EVO 1TB
Screenshot as mentioned above: https://gyazo.com/05271c7d88131bcd7b094a7a4b86653d