SpecTopics: PVC Misconceptions Explained

There are few construction products or raw materials that generate as much unnecessary controversy as polyvinyl chloride, commonly known as PVC. However, the “controversy” over PVC comes in the form of misconceptions and myths that have proliferated over its decades of use. Like most myths, the ones about PVC are often source less or based on a lack of understanding, but they gain a false credibility through repetition.

No matter what the myths are, the vast majority of construction professionals – manufacturers, product distributors, specifiers, and contractors – can attest to the safe, consistent performance of PVC in a variety of construction products, including roofing membranes, pipes, siding, and window frames to name a few.

Here are a few common misconceptions about PVC:

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Myth: The alternatives to PVC are “greener” and their production, shipping, and use have less of an impact on the environment.
PVC (sometimes simply referred to as “vinyl”) is perhaps best-known for its durability, but it also receives high marks for its sustainable attributes. PVC is extremely low-maintenance, easily recyclable, and it doesn’t off-gas or leach harmful chemicals if it comes in contact with water. In addition, the PVC manufacturing process does not require a great deal of energy and the PVC itself is lightweight, which dramatically reduces the carbon footprint of producing and shipping PVC products. Additionally, PVC is comprised of 57 percent chlorine, which is derived from industrial-grade salt, an extraordinarily abundant material. The chlorine can be chemically unlocked from salt through simple industrial processes. Even among other plastic alternatives to PVC, which are heavily dependent on petroleum, PVC shines for its low carbon footprint.

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Myth: PVC is highly flammable, and when burned in waste heaps or accidental fires, PVC off-gases toxic fumes, dioxins, and hazardous chlorine gas.
The myth about vinyl off-gassing toxic fumes can be easily addressed by pointing out three widely recognized properties of vinyl.

1. Vinyl building products exhibit superb fire performance, in large part because the material is self-extinguishing when the source of the flame is removed.
2. Vinyl building products are based on a naturally fire-retardant polymer.
3. The vinyl that is most prone to exposure during fires – roofing membrane – is often treated with additional flame retardants, which makes vinyl “slow to catch fire” and can dramatically reduce the spread of fire in the event of a building ignition. So, the question of off-gassing is partially addressed by the fact that vinyl doesn’t burn very well.

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Myth: PVC can’t be recycled and is a significant contributor to the global accumulation of plastic waste.
Few products are more readily recyclable than PVC; in fact, PVC can be recycled many times over without degrading the component materials, enabling it to be used in multiple product life cycles. Many of the PVC products in use today are likely to contain PVC that has been reprocessed for use through a simple recycling process. Today, you will find recycled PVC in a wide range of uses, from new consumer products such as cookware and sterile medical products, to car parts and speed bumps on residential streets.

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There are more misconceptions outlined in the white paper “7 Myths About PVC – Debunked” by John D. Wagner, which is available on the Carlisle SynTec website and offers more in-depth information on PVC misconceptions. To read the white paper, click here.