Safety Information: Corrugated Stainless Steel Tubing (CSST)

If lightning strikes on or near a structure, there is risk that it can travel through the structure’s gas piping system and cause a leak and, in some cases, a fire. A bonding connection installed on a gas piping system, as with any metallic system within a house, will reduce the likelihood of electrical arcing to or from other bonded metallic systems in the structure, making arc-induced damage less likely.

Since 2006, all manufacturers’ instructions have specified direct-bonding and grounding of yellow corrugated stainless steel tubing (CSST) in new installations. CSST is a flexible, stainless steel piping system used to supply natural gas and propane in residential, commercial, and industrial structures. Standard CSST is coated on the exterior with yellow plastic. CSST is installed inside buildings and on the customer side of the gas meter outlet through gas piping that the Public Service Commission does not regulate.

For existing installations, if yellow CSST is found, it is strongly recommended that a licensed electrician be contacted to ensure the system is properly bonded and grounded.

The Maryland General Assembly has passed legislation to address this concern. The Flynn and Laird Act of 2022 (House Bill 1052) took effect on October 1, 2022. The Act expressly prohibits the use of non-arc-resistant jacketed CSST in:
(1) the new construction of a customer-owned natural gas or liquefied propane piping system in a building;
(2) a natural gas or liquefied propane piping system in a renovated property if the renovation affects more than 50% of the total square footage of the property; or
(3) a natural gas or liquefied propane piping system that requires the addition of a new gas line to the gas piping system.

On September 1, 2022 the Public Service Commission compiled the following report in response to Flynn and Laird Act of 2022 requirements in the 2022 Session Joint Chairmen’s Report:
Public Service Commission Report on Consumer Education and Protections Relating to Corrugated Stainless Steel Tubing

For more information concerning the safety of CSST go to or the American Gas Association.