AIR!!!, I hope not, Fox better have put Nitrogen in them
This is a known issue with Podium shocks. 2 of mine were empty (drilled out rubber plug and had a slight hiss) 1 had a little pressure (hissed for a couple seconds) and one seemed full (hissed for 10 or 15 seconds).
I put new caps and my dealer put 200 psi in mine (wild guess on their part). Shock Therapy recommends 200 so I was OK with it.