A burning question: is PVC the major source of dioxin emissions?
It seems that concern still exists that PVC products are a major source of dioxin emissions and that if PVC products were therefore banned, the risk of exposure to dioxins would be virtually eliminated.
Just last week, we had an inquiry from a consumer who was very interested in installing uPVC windows in her new home but was concerned because she had read on the internet that they could emit dioxins during use. Such misinformation around dioxins is really troubling.
So what is the connection between PVC and dioxins and is such concern warranted?
Dioxins are a group of toxic compounds that are formed unintentionally during combustion processes such as waste incineration, forest fires, backyard bonfires and in many industrial processes. To form, a minute amount of chlorine is required together with a particular range of temperature and oxygen concentration conditions, constituting poor or incomplete combustion.
Because of the need for chlorine to be present, this has led to the association of dioxins to chlorinated compounds, like polyvinyl chloride, PVC. However, it has been well established now that the presence of more chlorine during combustion doesn’t equate to more dioxins being formed; that is, there is not a direct quantitative relationship between chlorine content and dioxin formation.
PVC contains chlorine, derived from the electrolysis of salt, NaCl. It has been claimed by some that since the production of PVC consumes about 30 percent of the industrial chlorine produced globally, PVC must be the largest source of dioxin emissions: chlorine in, dioxins out. But this argument is ill-founded since dioxins are only formed as a by-product of combustion; PVC or other materials containing chlorine – like salt – do not emit dioxins in their normal state.
Dioxin formation can occur in the chlorine production process where graphite anodes are used. Many industrialised countries replaced the graphite anodes in the 1970s.
Industrial emissions of dioxins peaked in the 1980s. Active abatement policies including regulations on combustion processes and incineration have dramatically reduced emissions from industry by 90 percent in Europe and the US, yet the production of PVC over the period has increased threefold. PVC production is clearly not positively correlated to dioxin emissions.
So what are the sources of dioxin emissions?
Essentially, any process involving combustion in the presence of a minute amount of chlorine can lead to the formation of dioxins under certain temperature and oxygen conditions. Thus burning PVC in the open or in a building fire could lead to dioxin emissions, just as burning timber (because trees, as living matter, contain chlorine ions) or a sausage on your barbeque (because it contains salt) could. Diesel engines, production of zinc, aluminium, iron & steel, bricks, cement and ceramics, timber kilns and many other industrial processes, including manufacturing the precursors to PVC, can be sources of dioxin formation.
Dioxins are Persistent Organic Pollutants (POPs) and for many years there has been an international effort to address POPs globally. Australia is a signatory to the Stockholm Convention on POPs and, as part of its obligations under the Convention, the Federal Government undertook an inventory on dioxin emission sources, the update of which was published in 2004 . This found that uncontrolled combustion processes - including waste burning and accidental fires, but most significantly influenced by emissions from grass and bush fires - contribute approximately 75 percent of all emissions in Australia. Ferrous and non-ferrous metal production (aluminium, zinc, steel etc) accounted for nearly 9 percent of total emissions in Australia, while local PVC manufacturing was negligible (less than 0.001 percent of the total).
Australia’s Action Plan to reduce dioxin exposures and emissions does not refer to PVC products or production; it does include actions to be implemented for some other (non-PVC related) industrial processes.
It’s not what you burn, but how you burn it that is important.
Regulations on open burning together with modern incineration and industrial combustion processes are proving successful in minimising emissions of dioxins and have contributed to the significant falls in emissions in developed countries. Life cycle assessments and regulatory monitoring of PVC manufacturing show that dioxin emissions from the PVC industry are extremely low.
So should we still be concerned about dioxins?
Yes, they are considered highly toxic and carcinogenic, because of their persistence, bioaccumulation and prevalence in the environment; and yes, we should minimise their formation and our exposure to them.
Would not using PVC make a difference? No.
Read more about the effective managment of dioxins in PVC manufacture and incineration in the following VinylPlus publications:
The increasing use of PVC in the construction and furnishing of buildings over the last 60 years has led to a thorough assessment of its fire performance.
In a fire, the distinguishing characteristics of rigid PVC are:
Although PVC will provide a source of carbon fuel to a fire once it has started, it will self-extinguish if the external heat or flame source is removed because of the chlorine present in PVC. This is a significant positive for fire safety.
Additives may change the performance of flexible PVC in a fire. Some plasticisers, for instance may increase the material’s impact during a fire. Alternatively, many flexible PVC products are modified with fire retardants, increasing their safety.
Burning PVC releases a heavy smoke. Nevertheless, the toxicity of PVC emissions from accidental building fire is no worse than many other common materials. The most important product in any fire, after heat, is carbon monoxide (CO), which is produced by all organic materials when they burn. Heat and carbon monoxide are by far the major cause of building fire deaths.
Another dangerous gas is hydrogen cyanide (HCN) produced, not from PVC, but from nitrogen-containing materials such as some natural fibres.
The two most common irritant gases produced in fires are acrolein (from both natural and synthetic materials such as wood) and hydrogen chloride (HCl), from chlorine-containing materials, including PVC. Hydrogen chloride has a very pungent odour and is therefore quickly detected. At the levels encountered in building fires, hydrogen chloride remains an irritant and is not lethal. However, it may become corrosive to other materials when in contact with moisture.
The overall toxicity of emissions from PVC in a building fire is comparable to that of some hardwood timbers.
Newly developed PVC formulations e.g. Flame Retardant PVC (FR-PVC) have significant benefits in terms of lower acid emissions, smoke generation and enhanced fire resistance.
To our knowledge, no building fire fatality has ever been attributed to PVC by building fire authorities.
There are too many LCAs involving PVC to list them all. A few studies are provided here for your reference:
Life Cycle Meta Studies
There are few, if any, municipal waste incinerators in Australia but a number of medical waste incinerators operate throughout the country. Incineration, with or without energy recovery, is used extensively in the US, Europe and Japan.
Municipal and medical waste incineration can be - and were, in the past - a significant source of dioxin emissions. However, it has been widely demonstrated that the total chlorine content of the feed to these incinerators has little impact on dioxin output as only a very small amount of chlorine needs to be present to lead to dioxin emissions [Rigo, HG, Chandler, JA & Lanier, WS, 1995, The relationship between chlorine in waste streams and dioxin emissions from combustors, The American Society of Mechanical Engineers]. Although PVC products have a relatively high chlorine content, other sources of chlorine in waste include food waste (contains salt), wood, paper etc.
The level of dioxin emissions from incinerators is the result of the combustion temperature and the efficiency of operation, both of which can be controlled with the use of modern incineration technology. PVC in the waste stream of properly operated incinerators has negligible effect on the amount of dioxin emissions.
The Swedish Environmental Protection Agency (EPA) found reducing the PVC component of the total combustible waste “… will not change the amount of dioxin emissions in flue gases, or significantly reduce the dioxin content in residual products from flue-gas treatment plants” [Swedish EPA, June 1996, Report on Disposal PVC Waste].
Similarly, Australian Dr. John Scheirs reports that, with respect to the incineration of municipal solid waste, there appears to be little relationship with the proportion of PVC in the waste and dioxins produced, since chlorine from other sources is already present [2003, PVC Final Report [http://www.environment.gov.au/archive/settlements/waste/index.html].
When PVC is burnt or incinerated, the major by-products are carbon dioxide, water, hydrogen chloride and metal chlorides. Hydrogen chloride is an acidic gas which must be removed from the emissions of waste incinerators. The gas is filtered out using equipment called scrubbers. Scrubbers are fully enclosed within the incinerator and are compulsory in modern waste incinerators. The presence of PVC in the feed stream increases the use of caustic soda to balance the scrubber effluent.
There are several modern German incinerators that recover HCl. There are also processes today that are able to recycle incinerator residues. These include the Halosep process and the Neutrec process.
Read more about the effective managment of dioxins in PVC manufacture and incineration in PVC & Dioxins and in the following VinylPlus publications:
Dioxins and PVC - A troubled past, a brighter future
PVC waste incineration and HCl.
PVC resin is non-toxic and inert and can be disposed of safely in landfill. Nevertheless, as there is a growing scarcity of suitable landfill space, recycling, incineration and waste to energy are considered better options for disposing of PVC.
There is no evidence that PVC products, consisting of resin, additives and other materials, contribute to the toxicity of leachate in landfill. A 2003 report by Dr. John Scheirs for Environment Australia found:
"On the basis of the available research and evidence the landfilling of end-of-life PVC seems to be environmentally acceptable when mechanical recycling and thermal treatment processes are not possible. The overall conclusion of the most recent studies is that PVC products do not constitute a substantial impact on toxicity of landfill leachate and gas."
View Dr. Scheirs’ full report: PVC Final Report [http://www.environment.gov.au/archive/settlements/waste/index.html]
Concerns have arisen about vinyl chloride occurring in landfill. The gas can form when chlorinated hydrocarbons break down. Studies report that because PVC shows no sign of degradation in landfill, vinyl chloride gas does not originate from the PVC.
In Australia, a high percentage of Australians have access to kerbside recycling of plastics packaging, where waste is collected, sorted according to type and, ultimately, processed into new products either in Australia or overseas.
The Vinyl Council commissioned a national PVC Waste Audit, conducted by Nolan ITU in 2005, to understand and gather data on the amount of PVC waste entering the waste stream in Australia annually. The research found that less than one per cent of the 16-20 million tonnes of waste sent to landfill each year in Australia was PVC.
More than 85 per cent of PVC resin manufactured every year, is used in durable products and therefore less PVC is recovered from household waste than other more common packaging plastics such as PET or HDPE. Highly durable PVC products (more than 15 year life) include building materials such as window frames, water distribution and drainage pipes, floor coverings and electrical cable insulation. PVC products such as pipe last 100 years so little of this material enters the waste stream.
About ten per cent of PVC resin consumed is used in products which remain in use for between 2 and 15 years. Car parts and furniture are examples.
Less than five per cent of PVC resin consumed is used to make products which last for less than two years. Single-use products, such as medical equipment, are included in this category. PVC packaging materials have a short life and most frequently end up as household refuse. PVC bottles and containers are included in most kerbside collection schemes in Australia.
Under the Australian industry’s PVC Stewardship Program, Signatories in the industry have committed to consider whole-of-life management of their products and to address waste and recycling issues.
Billboard skins, banners, truck tarpaulins and grain covers. These are a few of the common uses of PVC coated polyester fabric. Durable, light weight, water tight, with good tensile strength, vinyl coated fabric protects against weather and damage. However, the combination of two plastics as woven fabric (PVC and PE) makes recycling difficult. Currently in Australia, virtually all this material goes to landfill after years of service.
Determined to find a solution, the Vinyl Council is working with a range of partners in Australia. It is estimated that 1.2million m2 of billboard skins are landfilled every year in in Australia. In additional, 4,000 tonnes of grain covers reach the end of their life in the agricultural sector every year.
In 2014, the Vinyl Council teamed up with Monash University and, with a Victorian Future Designers Grant, engaged four students to explore the recycling dilemma of finding an effective technology to reprocess the composite material and finding products that can absorb the recyclates.
Along with an expert team of product suppliers, manufacturers and reprocessors, the students explored a wide variety of processes including heat rolling, vacuum forming and pulverising. The project succeeded in identifying a number of potential applications ranging from 'pelt' for furniture to floor covering, and moulded components for complex products.
The project culminated in a design exhibition - ReForm - of the product samples, methods used and design ideas at Monash University School of Industrial Design in March 2015. The report of the project with images and descriptions can be downloaded here.
The Vinyl Council was successful in securing a grant from the NSW Environment Trust in late 2015 to continue to explore cost-effective options to recycle coated fabric in Australia through a project called REMAKE. In this project, the Council collaborated with University of New South Wales, Monash University, Council members and others in the PVC and recycling industries, the Outdoor Media Association and a potential end manufacturer. Several product design and reprocessing options were explored and developed.
The project used a participatory process to engage and pursue opportunities for a circular economy, including peer to peer exchange, and a very successful, participatory Design Lab event. Three product designs were subsequently proto-typed and are being assessed for commercial applicability.
A copy of the final report (2018) for the project is available here.
In 2018, the Victorian state’s Metropolitan Waste and Resource Recovery Group (MWRRG) provided a $20,000 grant to part fund an investigation into the feasibility of recycling vinyl coated fabrics into roof tiles, one of the product concepts identified in Porject ReMake. The VersrTile project enabled an expert multidisciplinary team led by the Vinyl Council to design and test reprocessing techniques and form prototype roof tiles made from waste billboard skins. The project outcomes included testing the manufactured sample tiles, which found the tiles could resist weathering as required under applicable standards; however, further development is required on the tile prototypes to meet mechanical strength tests required for roof tiles.
A preliminary business case has been developed to understand the financial and production factors that will be required to manufacture these roof tiles economically and to assess their commercially feasibility. The significance of this project is that it identifies a potential reuse of a composite material into a durable, high volume product without the need to separate the polyester fibre from the vinyl.
Winning Awards with Truck Tarp Kiosk
Congratulations to Monash University and Studiobird for winning 'Small Project Architecture' in the Victorian Architecture Awards, June 2015. Re-using the blue vinyl truck tarpaulins, their design makes full use of the malleable, water-tight features of the coated fabric to create a totally modern and playful design for a pop-up security kiosk at Monash University.
Vinyl is used in many diverse products. This section shows what is being done by the Vinyl Council and its members with the dominant types of products to recover and reprocess specific vinyl applications.
A) Looking to recycle end-of-use PVC?
Step 1. Contact the product supplier/manufacturer to see if they take back their own product for recycling.
Step 2. Contact the companies listed below. You can also visit http://businessrecycling.com.au/ for recyclers of other plastics or material types.
Step 3. Need further information on whether an end-of-use PVC prodcut is recyclable in Australia? Contact us at the Vinyl Council.
Note: Recycling will succeed when end-of-use material is recovered in a suitable form for reuse in another product. Recyclers want clean, regular and reasonable volumes (>500kg) of consistent material. They do not want spasmodic, irregular and small quantities of PVC contaminated by dirt, metals or other recyclables such as paper, or other plastics.
B) Looking for recycled PVC to use in new products?
Below are the contact details for companies who seek ongoing sources of end-of-use PVC for manufacturing into new products. If your company would like to be added to this list, contact us now.
|Iplex / Tradelink||NSW||07 3881 9578||Pipe. Iplex Recycling Centre, Chipping Norton, 8-2pm. Or contact your local Tradelink store re drop off.|
|RBM Plastics||NSW||02 9748 2638||Cable, conduit, possibly packaging and blister pack. Can granulate, compound, reprocess into own product.|
|MPE Plastics Extrusions||NSW||02 9601 8414||Flexible profile, clean cable, rigid pipe. Can granulate and pelletise.|
|Techplas||NSW||02 9636 6755||Pipe, windows, conduit and other rigid profile, industrial scrap only. Granulator.|
|Pipemakers Australia||QLD, VIC, WA||07 3344 3377||Rigid PVC products made by Pipemakers only. Granulator, compounder, fabricator.|
|Armstrong Flooring P/L||VIC||03 9586 5548||Clear (no colour) post-consumer & post- industrial PVC. Flooring manufacturer.|
|CryoGrind Australia||VIC||03 9794 6608||Medical IV bags, packaging bottles and blister packs, cable, ground material such as profiles. Will consider other products. Granulator and compounder.|
|Emmans||VIC||03 9462 1644||Pipe, cable, gift cards. Granulator and machine maker.|
|NWC Recycling||VIC||0438 565 640||Pipe, windows and profiles, cards. Granulator.|
|Rojo Pacific||VIC||03 9872 1000||Advertising banners, tarpaulins. Printer, importer.|
|Welvic Australia||VIC||03 9361 8700||Medical IV bags, packaging, cable, profiles. Will consider other products. Granulator, compounder.|
Would your company like to advertise its PVC recycling capability? Contact us at the Vinyl Council.