In houses all over the country, the gas that fuels stoves, water heaters and other appliances is delivered through a flexible tube made of corrugated stainless steel wrapped in a yellow jacketing, and the Charleston Fire Department’s Fire Marshal Division, is warning people about it.
The problem is lightning. When it strikes on or near a structure with yellow corrugated stainless steel tubing – or CSST as it’s known in the industry – an electrical surge can travel through the piping, and if along the way it passes near other metal, that electrical energy may arc to that other metal. That arcing electricity can punch a small hole in the sidewall of the tubing and ignite the gas that leaks out, starting a fire.
“That's what happens when we have lightning energize the gas pipe system and that piping comes into contact with something else. Could be a steel beam in the house, could be a steel plate, could be an electrical wire. There's essentially a flash, a small pinhole and we end up with a gas-fed fire,” said Deputy Fire Marshal Rick Anewalt. “That [fire] could be in the crawl space. That could be in the attic.”
He and Chief Fire Marshal Mike Julazadeh talked to the Daniel Island Neighborhood Association about CSST last week as part of a CSST safety campaign the department is undertaking. It includes speaking to neighborhood associations around the city, training building and fire inspectors, and spreading information on social media.
Yellow corrugated stainless steel tubing is a product of Japan developed in the 1980s as a safer alternative to the rigid black iron pipes of the past that had a bad tendency to fail and cause fires during earthquakes. In contrast, CSST is flexible, so it can better withstand a wiggling earth.
Americans took notice of the new product, and in 1989, standards were released for how to install it. Contractors grew to love the stuff. It took a third of time to install as the old black iron pipe systems and had fewer fitting joints, which reduced the risk of leaks. By 2012, about seven million homes in the U.S. had CSST running through their attics, through their walls and underneath their floors.
But as time wore on, it became clear that CSST was not without its flaws either, and 2012 was also the year that the National Association of State Fire Marshals launched a nationwide CSST safety campaign.
Julazadeh told the neighborhood association that in the last five years, there have been about 30 house fires in the whole City of Charleston related to lightning strikes, about 30 percent of which were in the Daniel Island/Cainhoy area. As many as half of those on Daniel Island and in Cainhoy involved some kind of gas line rupture post lightning strike, though he emphasized that those are preliminary numbers based on available data.
As the Charleston Fire Department’s Fire Marshal Division continued to see fires involving lightning strikes in homes equipped with CSST, Julazadeh said they started to look into those incidents more closely. When they did, they discovered that municipalities all over the country were experiencing the same thing, so they started looking for ways to improve safety and get the word out.
As it turns out, there is something homeowners can do to decrease the risk of fire. For one, in recent years new kinds of CSST with different jackets – made in different colors – have been developed that seek to address the lightning threat. And if yellow CSST is installed today according to the manufacturer’s instructions in the design and installation guide (sometimes referred to as the D&I guide), the risk from a lightning strike can be significantly reduced.
That’s because in 2009, after a class action lawsuit settlement related to CSST’s vulnerability, building codes were revised to require an extra step to reduce the threat from lightning, and manufacturers changed their installation instructions in response. South Carolina did not adopt those new codes until 2013, so older installations may not have that extra step. But, it can be simply added retroactively.
The problem with corrugated stainless steel tubing comes when the energy from a lightning strikes arcs from the tubing to another metallic system. That’s what can cause the leak that can be ignited. So now, manufacturers call for the CSST system to be bonded to a ground, meaning the piping is fixed with a conductor – usually a copper wire – that connects to another conductive device that safely dissipates the energy into the earth. When the other metallic systems running through the house are also bonded to the ground, as they should be, even when lightning sends an electrical surge through those systems, it won’t arc.
Julazadeh cautioned that proper bonding and grounding does not totally eliminate the risk from a direct lightning strike.
"Truth of the matter is, you really can't predict what's going to happen if you have a lightning strike. There's so much energy that dissipates, you don't know where it's going to go and what's going to happen," he said.
In fact, the National Fuel Gas Code Handbook goes so far as to say protection against a lightning strike – direct or indirect – “is considered outside the scope of the various building codes.” But, proper bonding is intended to divert a lot of the energy in a bolt of lightning away from the CSST to the earth, making the arcing that pokes holes in CSST not as powerful and not as common.
Anewalt told the neighborhood association the purpose of their presentation was not to instill fear. He said CSST has been around a long time, and the vast majority of houses that have gas delivered through it have not burned down.
"It's just like when you get a recall for your car,” he said. “It doesn't mean that every car is going to fail, it just means that there's something you should look for.”
Anewalt and Julazadeh recommended getting more information from csstsafety.com. That can help determine whether to have a licensed electrician come and make sure your gas lines are properly bonded and grounded.
“If you can,” Anewalt said, “it might be preventative medicine for your home."