PVC, or polyvinyl chloride, is a type of plastic whose most widespread application is in the construction of pipes. This includes household plumbing, municipal water supply, sanitary sewer pipes and conduits in various industrial settings.
Health and environmental concerns regarding PVC have prompted questions like how to recycle PVC and where to recycle PVC pipe. Its tendency to emit harmful gaseous pollutants and microplastics that persist through the food chain has led to extensive research on the safe recycling of PVC and the integration of this research into municipal trash disposal and recycling policies and practices.
Why is PVC difficult to recycle?
What is PVC?
PVC is a polymer that is made up of hydrogen, carbon, and chlorine. Its physical properties include structural integrity and resistance to heat and various forms of corrosion like acids, alkaline substances, and alcohols. This makes it a preferred material for use in underground pipelines like water supply and to transport sewage that can contain many corrosive agents.
Since PVC in its original form tends to be brittle, plasticizers like phthalates are added to it to make it more flexible and pliable. This softer form is used in plumbing, cables, tubing, sheeting, and other applications where it is a substitute for rubber.
Chlorinated PVC boosts its chlorine content by more than sixty percent and is used to make it even more resistant to heat and corrosion.
Lesso PVC pipe is a brand that is used for almost the entire range of applications for which PVC can be used.
Why is PVC harmful?
PVC tends to degrade in a way that is harmful to the environment. The components that it breaks down into are carcinogenic, persist in the food chain, and negatively impact soil and air.
- During its lifetime, PVC gradually degrades and releases microplastic particles as it does so. These microparticles absorb persistent organic pollutants that are present in the environment. When animals ingest these microparticles, the persistent pollutants enter the food chain. They survive and travel through the food chain as they do not degrade, and as a result, they cause cancer and other health disorders.
- Phthalates that are used in PVC tend to leach into the soil and air under minimal stress and are hazardous. They disrupt the endocrine system and are possibly carcinogenic.
- When PVC combusts, it releases dioxins that are a proven hazard to human health. Dioxins can hamper development, damage the reproductive and immune systems, and cause cancer and diabetes.
- Ash from PVC combustion contains cadmium and lead, that are hazards.
Can I put PVC in my recycling bin?
Recycling policies differ by municipality. The city sanitation services in many cities provide recycling facilities to homes and apartment complexes. The types of material that they accept for recycling depend on the recycling practices and capabilities of each municipality.
PVC is accepted for recycling in some places and not in others. With the wide variety of plastics that are used in households and make their way into the trash, a universal numbering system has been developed to discriminate between the types of plastics. PVC is identified by the number 3.
If your city sanitation service has a recycling program, they will stipulate the material that they will collect for recycling, using the numbering system. If your city’s recycling program includes PVC, the number 3 will be specified in the list. PVC items will bear the number 3 in the recycling triangle for clear identification.
If your city does not accept PVC, the only other option is to dispose of it in regular trash or to contact PVC manufacturers who will recycle it and use the resulting material to manufacture more PVC products. There are also a few other eco-friendly recycling alternatives that can tell you what to do with old PVC pipe.
What are the challenges involved in recycling PVC?
- Landfills are where most regular garbage is disposed of. If PVC items land up in a landfill, they can pose a significant environmental threat. The chlorine and phthalates that are part of the PVC chemical composition gradually break down and are released. If they leach into the soil or groundwater, they can be a health hazard.
- When incinerated or burned, PVC releases hydrochloric acid, which is highly corrosive. While most trash incinerators have a toxic gas neutralization system built into them, some degree of leakage does occur. The resulting ash is also toxic as it contains lead and cadmium and is transferred to landfills where they turn harmful.
- Mechanical recycling involves grinding down the PVC so that it can be used to make more PVC products. But the varying compositions of different types of PVC means that the resulting product is not sufficiently homogeneous and a complicated pre-sorting process is required.
- Chemical recycling changes the chemical composition of the PVC but requires elaborate setups that cost more.
Which are the two main PVC recycling methods?
PVC mechanical recycling involves breaking down the physical structure of the PVC. It is ground into particles called recyclate, which in turn is used to manufacture more PVC products.
The main constraint with this process is that PVC has different chemical compositions because of additives that are added to increase its flexibility or its resistance to heat and corrosion. If these different types of PVC are pulverized together, the recyclate is not a uniform substance that can be used for one particular purpose.
One way to overcome this challenge is to not mix with the PVC with other plastics. Another solution is to mechanically recycle only post-industrial waste rather than post-consumer waste.
Post-industrial waste is composed of scraps and pieces of plumbing, piping, and cables from installation and construction sites. They can be collected directly from these sites and recycled into high-quality recyclate.
This involves breaking down the chemical structure of the PVC. PVC is broken down at the molecular level through processes like pyrolysis, hydrolysis, and subjecting it to high heat. The resulting hydrocarbons and other compounds like sodium chloride are recovered and used as raw material to make more PVC. The advantage of chemical recycling is that it can be used on post-consumer waste which is made up of different types of PVC and yet reclaim pure recyclate. The downside is that it is much more elaborate and expensive and the value of the recycled product is not high enough to justify this cost.
What are some other eco-friendly methods of PVC disposal?
- PVC waste can be donated to charities that are involved in housing projects. If you renovate your house or replace some damaged pipes, chances are that you will be let with a sizable amount of PVC plumbing, insulation, window framing, or cabling material. They can be re-purposed in other construction projects. This is easier than finding a way to safely recycle them.
- PVC manufacturers can re-use and upcycle waste or scraps from their manufacturing processes, preventing the waste from entering landfills.
- Homeowners can use scraps like bits of pipe or insulated wiring for other small DIY or home improvement projects instead of buying new material. Reusing the PVC waste can keep it from entering the landfill and posing a threat to the environment.
- Several environmental initiatives like RecoVinyl and VinylPlus in Europe are paving the way to find more sustainable uses for PVC and to find more eco-friendly additives that can render it harmless to air, soil, and groundwater.
If you are asking yourself, “Can I put PVC pipe in my recycling bin?”, the answer is that you probably can, and if not, there are a few ways to safely dispose of it. PVC recycling involves many challenges but it is worth going that extra mile to save the environment and mitigate the danger that it poses to human health. Environmental policies and programs that provide incentives for recycling have come a long way in driving this change of course towards a cleaner and safer planet. These policies include PVC waste disposal and finding safer alternatives to PVC in general.