.....take up welding "hobby"...many do! i worked 31 yrs in a production facility with an O2 tank in my office, and one in the car. an energy drink on the way to the tank and only gone for as long as a typical "break". depending on the job of course, you maybe could even drag a tank around with you....mine became nearly unnoticed. might have to discuss with HR re "reasonable accommodation"...dunno how that works in CA....