By: Anna Kiesewetter
PVC is all around us: it’s in our medical equipment, our records, our pipes, our curtains, our floors, and more. However, it isn’t around us only physically; its negative effects are also increasingly appearing, taking the form of toxic chemicals polluting our world as well as our bodies. But what is PVC, and why is it so harmful?
PVC, or polyvinyl chloride, is a plastic. Its chemical formula is CH2=CHCl, and its long chain of carbons, which are bonded to hydrogen, makes it an organic molecule. Now, as mentioned earlier, PVC is common in many of the objects we see on a day-to-day basis; as such, you’ve probably heard of PVC in relation to items such as PVC pipes or regular records. However, it is most commonly used for construction. To understand why this is the case, we’ll first have to take a look at the history of PVC. So, the first version of this plastic was created by French chemist Henri Victor Regnault in 1835, by first electrolyzing salt water to produce chlorine, then combining said chlorine with some ethylene extracted from oil, and finally heating it at high temperatures to become vinyl chloride monomer. However, this material wasn’t patented until 1912, when German chemist Friedrich Heinrich August Klatte used sunlight to polymerize vinyl chloride, which essentially means to combine two molecules to create a larger structure. Later, in 1926, Waldo Lunsbury Semon of the B.F. Goodrich Company plasticized PVC. He did this by dehydrohalogenating PVC in a high-boiling solvent, which removed a hydrogen halide from the substrate. Mr. Semon was responsible for the ensuing commercial success of the polymer, and in 1930, the Union Carbide Corporation created Vinylite, a copolymer or combination of vinyl chloride and vinyl acetate that became the material we today know as the vinyl used in phonograph records.
Now that we know how PVC was created, we can begin to look at why it is almost perfect for construction. The first reason being that PVC is chemically stable and won’t polymerize on its own. Additionally, it is also flame resistant, has good electrical insulation, is noncorrosive, and is resistant to grease, oil, and chemicals. To top things off, PVC is easily blended and processed, making it the ideal material to use in constructing all kinds of things, such as window frames, shutters, pipes, spare car parts, toys, packaging, and more.
All of this, of course, makes it the ideal building material. But here’s where the truth gets a little more murky; what we haven’t yet considered are toxic effects of PVC, which can not only impact the environment, but can also harm humans.
As world production has grown, the worldwide usage of synthetic chemicals and plastics has also grown. In the U.S. alone, over 50 million tons of synthetic chemicals were used in 1970, which tripled to 150 million tons by 1995. Of these synthetic chemicals, PVC is both the most widely used and the most environmentally damaging. There are two primary reasons as to why PVC is so harmful to the environment. First, it is the least recyclable of all plastics; in 1994, less than 0.5% of PVC in the U.S. was recovered through reprocessing. And second, its chlorine content; PVC contains organochlorines and chlorofluorocarbons, which are both extremely harmful to the environment. Organochlorines are resistant to breakdown, both in the environment and in animals’ bodies, accumulating in the latter’s fatty tissue. Chlorofluorocarbons released into the atmosphere destroy the ozone layer. This is particularly worrying due to the fact that as the ozone layer weakens, we are exposed to greater and more harmful ultraviolet radiation from the sun, which creates warmer temperatures that can make certain chemicals vaporize more easily and break down into toxic byproducts. Furthermore, the increased temperatures can also cause extreme weather events like hurricanes and fires, which can release even more toxic chemicals as homes and factories are destroyed. These toxic chemicals can also be endocrine disruptors and impact human metabolic processes, hindering our own adaptation to climate change.
What’s more is that PVC is also responsible for the greatest share of the U.S. annual production of dioxin, an incredibly toxic chemical created when chlorine-based chemicals are produced, used, or burned. The Environmental Protection Agency, or EPA, suggests that there are no safe levels of dioxins; exposure to any amount can lead to severe health damage, including cancer, diabetes, neurological damage, and reproductive defects.
Worse still, these negative health and climate effects disproportionately affect certain vulnerable communities. Take what’s become known as Cancer Alley in Louisiana, a predominantly Black and impoverished community. This community is situated along the Mississippi River, between Baton Rouge and New Orleans, which is a location populated by several factories, all of which pump out toxic chemicals, two of which being dioxins and carbon tetrachloride. The effects of this are extremely clear: the cancer rate in this vulnerable community is much higher than the state and national rate. To make matters worse, this community’s proximity to the Gulf Coast makes it even more vulnerable to the climate change PVC causes. And this cycle is not limited to Cancer Alley; 13 of 14 U.S. plants producing vinyl chloride monomers, the building block for PVC, are located in areas in Louisiana and Texas that are inhabited predominantly by poor Black communities. In 1987, the small town of Reveilletown, Louisiana grew so contaminated that 106 residents had to relocate, with every building torn down. Based on both of these examples, it’s evident that PVC’s health and environmental effects are extremely harmful to vulnerable minority populations in particular.
Now that we are familiar with a majority of the negative effects of PVC, we can begin considering potential alternatives for it. These alternatives can be split into two categories: non-plastics and plastics. Sustainable non-plastics are the ideal replacement, with materials like paper and wood replacing PVC and other plastics. This may not be realistic, however, as plastics are cheaper and easier to procure than non-plastic replacements. Furthermore, these alternatives not only still contribute to global waste in landfills, but also produce chemicals when burned. Other non-chlorinated vinyls can also be considered, as the chlorine in PVC is what makes it truly harmful. As such, the usage of non-chlorinated vinyls, such as ethylene-vinyl acetate (EVA), polyethylene vinyl acetate (PEVA), polyvinyl alcohol (PVA), and polyvinyl butyral (PVB), are all potential solutions to this PVC problem.
In terms of specific replacements we can make, let’s first take a look at building materials. Nexterra backed carpet tiles made of recycled nylon fibers have been shown to be a very cost-effective alternative for PVC carpet, with the added benefit of not releasing any dioxin or hydrogen chloride. However, nylon is still a synthetic material that isn’t biodegradable. Turning to natural animal or plant-based fibers, such as cotton and hemp, may be a more environmentally conscious choice, though more expensive. For harder flooring, calcium carbonate, titanium dioxide, and rubber are more sustainable options that do not contain PVC. For furniture, recycled content is the most environmentally-friendly option. This can include steel frames, sustainable wood, textiles, and PVC-free mesh, repurposed to create new furniture.
In the medical field, it’s important to find replacements for PVC, especially since PVC itself can create more medical complications. PVC is often used in extracorporeal, or outside the body, tubing, as well as blood bags. The problem with this is that the plasticizers in these PVC materials can leach out during use, which are often non biocompatible and can even cause complications, as the additives resemble the female hormone estrogen. To increase biocompatibility, researchers from the University of Tokyo and Tokyo Medical and Dental University have been investigating a new polymer alloy of polyethylene. They created this alloy by first dissolving polyethylene in xylene and n-butanol, then mixing the polymers, and finally heating the solution to create a transparent solution. Polymer films were then created by solvent evaporation and vacuum drying, and then the plastics were thermally cured under pressure. This new material, in fact, reduces platelet adhesion as well, or the sticking of platelets to the material. As such, this material is well-suited for medical devices and products that come in contact with blood—like tubing and blood bags. Other cost-effective non-PVC materials for intravenous bags include ethylene vinyl acetate and multilayer polypropylene, while nitrile gloves are much preferable and more durable than PVC. Though these non-PVC products may be more expensive than PVC products, we can largely minimize that price difference through purchasing them in large volumes.
So, as we can see, it’s important to continue searching for and implementing cost-effective alternatives to PVC so to protect our environment, as well as our public health. This is an imminent issue, primarily due to the fact that as the earth heats up, it’s going to impact the most vulnerable populations first. And though much damage has been done already, the sooner we work towards eliminating our usage of PVC, the sooner we can begin rebuilding.
Citations:
What Did You Learn?
Questions:
1. What is PVC?
Polyvinyl chloride is a plastic and organic molecule used commonly for construction because of its cheap and versatile chemical composition. Its chemical formula is CH2=CHCl.
2. What are some of the toxic byproducts of PVC?
Hydrogen chloride, carbon tetrachloride, and dioxins can all be released by PVC. These chemicals are all incredibly toxic for the environment, contributing to global warming and rendering some areas inhospitable.