Plastic-Free July: Why do we need to reduce plastic pipes in the built environment?

Plastic-Free July: Why do we need to reduce plastic pipes in the built environment?

To celebrate Plastic-Free July, the Copper Sustainability Partnership (CuSP) spoke to Paul Hagar from Safe Piping Matters to uncover the risks of using plastic pipes in the built environment and how we can reduce their use.

Paul Hagar

What impact does the construction industry have on the environment?

Constructing and operating buildings are responsible for significant CO2 emissions, with the United Nations Environmental Programme linking the building sector to 38% of the global total. Construction also represents a big source of pollution – the Alliance for Sustainable Building Products lists construction as the second-largest user of plastic in Europe and states that the industry generates close to 2 million tonnes of plastic waste per year.

Plastic piping materials have become increasingly common in recent years, but what are the risks of this material to the planet?

The risks vary by type of material, but PVC plastic pipes are particularly harmful. The Healthy Building Network says the entire PVC supply chain uses one or more types of “toxic technology” in its production, including mercury and asbestos. A new report from Beyond Plastics named ‘The Perils of PVC Plastic Pipes’ also identifies the numerous ways that toxic PVC plastic and its hazardous ingredients – including vinyl chloride – cause serious harm to people and the environment all along the plastics pipeline.

What effect does the production of plastic piping have on the environment?

Plastic production facilities are big polluters of air and water and the first part of the lifecycle has a big impact. Plastic comes from fossil fuels, using oil and natural gas to generate the pellets that become feedstock for manufacturing pipes and other products. Plastic manufacturing has exploded over the past 30 years and the United Nations predicts that impacts from production will grow a further five times by the end of this decade.

What happens to plastic pipes at the end of their life?

They are either landfilled, adding to plastic pollution, or incinerated, emitting toxic chemical by-products, and further amplifying their carbon footprint. Recent research on microplastics pollution and chemical leachates from plastic waste in landfill shows significant negative impacts on water, air and soil.

What about the safety of plastic pipes? Can they withstand a building fire?

Plastic pipes used for drain, waste, vent, water distribution and sprinkler systems are combustible yet, despite this, they run through buildings. Construction teams must put more complex assemblies in place to offset the risks posed by melting and burning plastic pipes, adding components that will prevent fires from moving from room to room via holes left by melted and burned plastic pipes. In practice, fire safety experts often find these more complex systems are installed incorrectly. Safe Piping Matters has just released a report with recommendations on firestopping, which can be read on the Safe Piping Matters website.

How do synthetic materials compare to natural materials in a building fire?

The Fire Safety Research Institute conducted an experiment and found that interiors with more plastic and synthetic materials became fully engulfed in flames in less than five minutes. By contrast, an interior using materials like metal, wood and natural fibres lasted more than 29 minutes before it was fully burning. The implications of this extra time on allowing occupants to escape, and fire fighters to put out the fire, are clear.

Can plastic pipes cause water contamination and leaching when they burn? What compounds are released and what effect does this have on health?

Andrew Whelton of the Centre for Plumbing Safety at Purdue University has studied what chemicals are released into water from melted and burned plastic pipes. He found carcinogenic benzene at levels 40,000 times the safe limit, as well as scores of other chemicals with negative health effects. What’s even more concerning is the fact the chemicals released have unknown effects on health and safety – we simply don’t know what they will do.

With leaching in mind, are there certain applications where plastic pipes can’t or shouldn’t be used?

The conditions for safe and reliable installation of plastic pipes vary by the type of plastic material used. Speaking generally, plastic pipes are more susceptible to leaching when exposed to heat and they can also be impacted by the substances flowing through them, due to chemical interactions with the pipe material. Plastic manufacturers publish extensive lists of building conditions and chemical exposures that can damage the pipes they make.

And what about the chemicals plastic pipes release into the air when they burn?

According to the report ‘Releases of Fire-Derived Contaminants from Polymer Pipes Made of Polyvinyl Chloride’ PVC plastic pipes emit toxic substances when they burn including methylene chloride, allyl chloride and vinyl chloride – all of which are carcinogenic. A study from the Firefighter Cancer Support Network shows clear correlations between the increased use of plastics in buildings and the incidence of cancer over the past 30 years.

What piping materials offer a safe, sustainable alternative to plastic?

There are several options for piping systems inside buildings that can limit leaching and fire risks, as well as avoiding the environmental and pollution impacts of plastic production and disposal. For example, copper pipe is a resilient, stable and highly recycled material. Iron and steel also perform similarly to copper in terms of both stability and recyclability.