Always store your oxygen equipment in a well ventilated area. An oxygen cylinder must be secured at all times; put it in a cart or lay it down flat. Do not carry liquid oxygen in a backpack or other enclosed space. Carrying cases, shoulder or hand bags, shoulder straps and backpack oxygen units are available to provide proper ventilation for the unit to ensure safety. Take precautions to avoid skin contact when filling your portable liquid oxygen tank, as frost buildup could cause injury.