NFIRSGram: CSST installation as a contributing factor in a fire

This NFIRSGram explains how to identify Corrugated Stainless Steel Tubing (CSST) installation as a contributing factor to a fire using the National Fire Incident Reporting System (NFIRS).

In the United States, approximately 500,000 new homes per year have CSST installed in them — approximately half of the number of new homes built each year that use gas for heating and cooking. As of 2012, an estimated seven million homes in the U.S. had CSST installed. Since 1989, approximately one billion feet has been installed in residential, commercial and industrial structures. Source: CSST Safety

Several jurisdictions have contacted the NFIRS Support Center questioning how they could identify yellow CSST as the possible cause of a house fire. As with all approved gas-piping systems, CSST is safe when properly installed. When improperly bonded or grounded, a power surge from a lightning strike near a home with CSST gas lines can puncture the membrane of the CSST. The escaping gas can then be ignited either by the electrical discharge of the lightning or another heat source in the immediate vicinity.

The NFIRS does not specifically list CSST as equipment, and since the issue with CSST is an installation issue, the U.S. Fire Administration recommends the following when identifying CSST installation as a contributing factor in a fire.

Need more help identifying CSST installation as a contributing factor in a fire? Please contact the NFIRS Support Center: Monday – Friday between 8 a.m. – 4:30 p.m. ET, at 888-382-3827 or by email at