Can you use pex tubing for gas line?

No, PEX tubing is not suitable for gas lines. It is designed for Plumbing applications, specifically for water supply lines, and does not meet the necessary standards for gas transport due to its susceptibility to degradation from gas compounds. For gas lines, it's essential to use materials specifically approved for that purpose, such as black iron, copper, or flexible gas piping. Always consult local building codes and regulations when selecting materials for gas installations.