Excessive Rust on gas line

What would cause this excessive rust on the gas line? There is a CSST gas line for the direct vent fireplace attached to the line.


Black iron pipe rusts easily when exposed to moisture. This is why it is usually painted if located in an area where it may be exposed to the elements. This pipe appears to be in a basement type location. From the picture, all the other materials appear clean. If the environment is not excessively moist and you have verified that leaks are not traveling down the pipe from the exterior, condensation or other potentials, you may want to consider that the this is how it was installed. It is not uncommon for fittings to come off out of the plumbers truck this way (Food for thought).

That is excessive?!