Alternatives to PVC

It’s once again a bad news week for PVC (polyvinyl chloride, or vinyl). In the US, a freight train carrying materials for PVC manufacturing derailed in what can only be described as a “fiery wreck”, releasing five tankers’ worth of highly toxic, flammable, and carcinogenic vinyl chloride gas. Close to 2,000 residents from the nearby Ohio town were evacuated, and the emergency management officials handled the incident in the only way possible: quickly venting the rest of the gas into the environment.

Shortly afterwards, US Customs and Border Protection added PVC products to the list of imported goods to be scrutinised for forced labour in the supply chain. Importers must prove that the goods have not been manufactured in China’s Xinjiang Uyghur Autonomous Region (XUAR), where a government program of forced labour has made PVC (and other products) very cheap.

All of this once again brings to the forefront the issues with PVC, from hazards to social justice. We’re giving a brief overview of the problems from a green chemistry perspective, and identifying some options for companies who want to move away from PVC.

What is PVC?

PVC, also known as polyvinyl chloride or vinyl, is a type of plastic with many different uses. It is highly durable, cheap, and can be made flexible or rigid as needed. Therefore it shows up in lots of household uses, like flooring, shower curtains, hosepipes, and children’s toys. Around 40 million tonnes of PVC are produced each year.

What is PVC used for?

PVC has many different uses because of its appealing properties. Some common uses of PVC include:

• Building and construction
  Windows, doors, shutters, sheets, flooring, pipes, and more
• Electronics
  Cable and wire insulation
• Automotive
  Interiors, seat coverings, dashboards, structural parts
• Medical
  Medical devices, blood storage bags, etc.

What’s the problem with PVC?

PVC is made from vinyl chloride (also known as vinyl chloride monomer, or VCM), which is a highly toxic, flammable, carcinogenic gas. It’s hard to contain, and easily absorbed by inhalation or skin contact, making it hazardous for both workers and the environment. In workers who are regularly exposed to it, it can cause liver toxicity, neurological symptoms, and cancer, among other things.

Even with all possible safety precautions taken, accidents still happen. The scale at which PVC is produced means that these accidents can be large and very damaging. Often, the accidents happen near disadvantaged communities, who are disproportionately housed near industrial manufacturing and waste disposal sites—an example of environmental injustice.

There are additional environmental and social justice concerns with PVC. Roughly 10% of the world’s supply of PVC comes from China’s Xinjiang Uyghur Autonomous Region (XUAR), largely from two state-owned chemical giants. A thorough report from Sheffield Hallam University and Material Research in 2022 described the links between forced labour, environmental pollution, and the resulting low cost of XUAR PVC. Indigenous Uyghur residents are conscripted by the state to live in dormitories and work in factories against their will, often without pay. The factories use coal and mercury in a particularly damaging manufacturing process, posing an extreme danger to the workers, local environment, and global climate. Profits are soaring, and a new factory is expected to come online in 2024, adding an additional 49 million tonnes of carbon dioxide into the atmosphere every year.

After manufacturing, PVC is somewhat less hazardous. It often has phthalate plasticisers and other additives, which have hazards of their own and can leach out during use. This is particularly concerning for applications like children’s bath toys, where the toy is soaked in hot water and chewed on, creating optimal conditions for the chemical to enter the body. 

Can PVC be recycled?

With many plastics, recycling can reduce the environmental impact by reducing the need for raw material. With PVC, recycling can actually cause more problems, as the harmful additives in the plastic go through the cycle and end up in products that shouldn’t have them. It also interferes with recycling other plastics in a mixed stream. An EC report in 2022 found that about one third of PVC waste is being recycled, with the remainder being landfilled or incinerated. In landfills, PVC waste leaches toxic additives into the soil and air. Incineration of PVC waste releases compounds that contribute to acid rain and formation of hazardous dioxins and furans, though this can be controlled through careful management practices.

Alternatives to PVC

Finding environmentally friendly alternatives to PVC can be challenging, and the right answer will depend on the specific application. The EC released a report in 2022 looking at the role of PVC in a non-toxic environment, and found quite a few replacement options for specific applications. A few of these alternative materials for PVC are listed below.

• Pipes: polyethylene, ductile iron, polypropylene, stainless steel
• Windows: wood, aluminium, fibreglass
• Electrical cables: chlorinated polyethylene, thermoplastic elastomers, cross-linked polyethylene
• Flooring: wood, natural linoleum, tiles

Linoleum vs. vinyl flooring

Since the terms linoleum or lino are often used to refer to vinyl flooring, you might be surprised to learn that actually, they’re different materials. Linoleum is a material that was popular in the late 1800’s, but from the 1950’s on began to be replaced by carpet or vinyl (PVC) flooring. The two materials are quite similar in performance, but actually drastically different in chemistry and safety.

The original linoleum (now sometimes called natural linoleum) is actually bio-based and biodegradable, and very low-hazard compared to PVC. It’s made of linseed oil, pine rosin, wood flour, cork dust, calcium carbonate, and pigments, with a woven jute backing. These feedstocks are largely natural, and much safer for transport and manufacture—no carcinogens or flammable gases here! Linoleum waste can be industrially composted, and breaks down harmlessly if sent to landfill. 

Despite all of these improved metrics, linoleum is quite durable, and expected to last 20-40 years. It may occasionally need re-waxing to keep it safe from moisture, and is more expensive than vinyl competitors. Life cycle analysis of linoleum from 2004 suggests comparable or slightly better environmental impact versus PVC, but more recent figures are hard to find. Manufacturing sustainability could be improved by using less intensive oil feedstocks, like tall oil, alternative pigments, or generally intensifying the process to reduce energy and materials waste. Best of all, there are European linoleum manufacturers who are transparent about their manufacturing sites. With suppliers committed to transparency and good practices, it’s much easier to keep track of where your chemicals come from, and who they harm along the way.