Plastic Pipes – A Fire Safety and Cancer Causing Health Risk?

Developers and building owners should think twice before allowing plastic pipes to be installed in buildings. Plastic piping materials can increase fire risk by encouraging faster flame spread, burning hotter, and emitting toxic smoke. Nearly two out of every three firefighters in the line of duty have died of cancer since 2002, according to the International Association of Fire Fighters, perhaps due to dangerous carcinogenic vapors and dioxins they can release. 

“Everything you buy today is laced with plastic,” Boston Fire Chief Joseph Finn told CBS News. “So, once they decompose and they combust they’re going to give off all these toxins and carcinogens that are really deadly to firefighters.” 

Plastic piping has a maximum operating temperature of 140 degrees, and when it reaches a melting point of roughly 170 degrees, it can emit toxins such as mercury, phthalates, and carcinogenic dioxides into the air supply. For this and other reasons, the International Association of Fire Fighters (IAFF) and the United Association of Plumbers, Fitters, Welders and HVAC Service Techs (UA) recently called for a ban on plastic piping in hotels, hospitals, nursing facilities, high rise residential structures, and healthcare facilities. 

Firestopping Vital to Safety

“The Model Plumbing Codes barred plastic plumbing pipes from high rise buildings for decades but have been weakened by special interests which jeopardizes health and safety,” says the statement. PVC (polyvinyl chloride), a widely used plastic material for piping is installed by simply being “punched” through a wall. Its combustibility requires more complicated fire-stopping gaskets and products to protect the opening, but a common error in plastic piping installation omits proper smoke seals, potentially allowing toxic smoke to seep through barriers and spreading. Plastic is also an intumescent material that has the potential to expand up to 35 times its initial volume in the event of a fire. This represents a major fire-stopping issue as it allows fire/smoke/gas to penetrate through barriers (such as a wall) into the spaces beyond.

Some plastics, such as polyethylene, can melt, dripping hot material that could cause a fire to spread. Plastics have very high flame spread characteristics, reaching up to two feet per second, 10 times the rate of wood. The sporadic nature of plastic’s melting and running also creates difficulties for fire investigators in determining the origins of a fire.  If improperly installed, these systems allow fire to spread more easily. Plastic pipes also produce more smoke than any other building material.

According to Fire Chief Finn, nearly 200 of his colleagues have died of cancer since 1990, a figure that he says indicates the leading cause of death for his firefighters by a wide margin. At the IAFF Cancer Summit in 2018, Finn referenced a power-plant fire in Boston that led to a significant number of his firefighters battling cancer later in life. This example demonstrates how a single instance of exposure to highly toxic smoke can have delayed but still deadly consequences.

The risks from plastic piping also occur as fires are burning. A recent study found that burning plastic piping generates high levels of hydrogen chloride (HCI), a “known toxic gas with extreme corrosive potential in the human lung,” and concluded that fires in structures with PVC piping can result in “lethal consequences for occupants.” Hydrochloric acid has a very short release time, and can cause severe burns to eyes and lungs… “an important cause of toxicity to firefighters and people exposed to fumes and smoke.” PVC is full of chlorine, and the burning of such results in the release of hydrogen chloride gas and dioxin in the form of dense smoke, which when inhaled can have serious, life-threatening consequences.

Water Threats

Research also shows that plastic can contaminate drinking water by leaching unsafe chemicals into the supply. A study by Purdue scholar Dr. Andrew Whelton on PEX plastic piping discovered odors in drinking water exceeding the EPA’s guidelines in each of six PEX pipes tested. They leached chemicals such as toluene (a neurotoxin), and MTBE, a known carcinogen that has been banned as a gasoline additive. The pipes tested in Whelton’s study were only six months old, which means that chemical leaching in plastic piping does not result from deterioration, exposure to UV rays, or expired material. The study shows us that plastic pipes leach chemicals into drinking water from the very early stages of their life cycle. 

These findings represent a small portion of the 150+ contaminants that have been found in water flowing through PEX piping. A study released by consulting firm Gradient identified 163 substances, 74 of which had limited criteria for monitoring water quality. The specific chemical groups of the contaminants found included halogenated compounds (an environmental pollutant), Organotin (commonly used for pesticides and paints), alkylphenols (known to disturb the human hormone system and heighten chances of breast cancer), and hazards such as hydrocarbons and phthalates that have been known to damage the liver, kidney, lungs, and reproductive system. 

In addition to Whelton, environmental scientist Tasha Stoiber and others have called for piping manufacturers to make their drinking water testing results public in order to increase awareness on leeching and water safety. 

Emerging Policy Changes

Similar to how plumbing codes have prohibited plastic pipes from high-rise buildings, code changes are needed to limit the installation of plastic pipe in critical patient occupancies. There are a number of safe, sustainable, and recyclable piping materials that do not pose these health risks to the public. Developers, builders, and code officials need to reduce and restrict the use of plastics installed in buildings before they cause harm to either firefighters or building occupants. Read the IAFF release that calls for such measures to be taken.