Stabilisers give PVC resilience. In the past, heavy metals – particularly lead and cadmium - have been the main source of stabiliser compounds. Today, the use of these metals is being phased out in many industries because of the occupational health and environment hazard associated with processing these metals.
The risk from exposure to heavy metal stabilisers in existing PVC products is very small.
Lead has been the most commonly used stabiliser and the risk associated with its use has been carefully assessed. Stabilisers form only a small proportion of the PVC formulation (typically less than two percent by weight) and they are strongly bound into the polymer matrix. Therefore the likelihood of migration of the stabiliser from the polymer is very small.
A Commonwealth Scientific and Industrial Research Organisation’s (CSIRO Australia) review of the issue concluded "Losses to the environment are limited during the use phase of the product...the contribution PVC makes to the levels of heavy metals in landfill waste is negligible."
Changing Stabiliser Use in Australia
In Australia, the PVC industry’s Product Stewardship Program (PSP) includes a commitment to avoid lead and cadmium based stabilisers. The phase out of cadmium-based stabilisers by PSP Signatories was completed by July 2004. The commitment for Signatories to remove lead stabilisers from all products is largely complete. Use of lead stabilisers by Signatories has been reduced 99% between 2002 and 2012. It was phased out of pipes and fittings produced by PSP Signatories by the end of 2008, and from almost all other applications by the end of 2011.
Refer to the sections on the Product Stewardship Program and progress against commitments for more detail.
Alternative stabiliser compounds being used in place of lead and cadmium compounds include calcium zinc, barium, tin and organic based stabilisers.
The following alternatives to lead have undergone official scientific risk assessment by overseas government authorities:
PVC is supplied to factories either as a powder (resin) or, when additives are included, in pellet or granular form as a ‘compound’. The PVC resin or compound is heated and shaped into a final product using a number of different manufacturing techniques.
Heat softens the PVC powder or pellets allowing it to be moulded or extruded into any shape or form. It can be made into pipe, sheet, wire or tape. It can also be used as a coating for other materials, like paper, cardboard or metal.
This versatility makes PVC useful across a range of markets and industries including:
Common PVC fabrication processes:
|Extrusion||Hot, soft plastic is squeezed through a hole of the required dimension, hardening as it cools.||Continuous lengths such as plastic sheet or pipe, window profiles, tile edgings.|
|Injection Moulding||Hot plastic is forced into a mould. When the PVC has cooled the mould is opened to remove the solid plastic object.||More complicated shapes such as pipe fittings, automotive parts.|
|Blow Moulding||Air is blown through a tube of hot plastic, pushing the PVC outwards to the sides of the mould.||Hollow objects such as bottles, jars and buckets. Also, car parts, PVC foam and plastic hardware.|
|Calendering||PVC is squashed between heated rollers to form thin sheets.||Rigid and flexible PVC sheet such as food wrap, flooring and credit cards.|
|Coating||Wire and metal mesh products are dipped in heated PVC then cooled. Coating protects metal from rust and abrasion.||Baskets, cables, coat hangers, tubes.|
Finished PVC can have excellent transparency or it can be made in almost any colour. Blending certain additives with PVC adds properties such as scratch resistance, flexibility and sunlight resistance. Many different mixtures of PVC are made depending on the final purpose.
PVC Use in Australia (based on tonnes of PVC consumed)
Chlorine (Cl) is a naturally-occurring chemical element, one of the basic building blocks of matter and an essential nutrient for plants and animals. It is one of the members of the ‘halogen’ group of elements, along with fluorine (F), bromine (Br), iodine (I) and astatine (At). Halogens contain seven outermost electrons which is a highly unstable configuration (eight is considered extremely stable) and they seek an additional electron to achieve a “stable octet.” As a result, halogens are always found in nature chemically bonded.
Because of its “pursuit” of a stable outer electron shell, chlorine is a highly reactive substance with the ability to combine directly with other elements. It can form many types of compounds, including salts, and is a good oxidiser.
Chlorine can be manufactured from a number of sources, most commonly salt or sodium chloride. It is used in the manufacture of chlorinated organic chemicals which make a significant contribution to modern building materials, healthcare and living standards, for example in:
There are thousands of naturally occurring “organochlorine” compounds — chlorine-containing organic compounds — that have been identified in living organisms.
The chlor-alkali industry
Chlorine production is inextricably linked to the production of caustic soda.
Chlorine and caustic soda are co-products, roughly evenly produced by the chlor-alkali industry. Since chlorine cannot be stored, chlor-alkali plants are operated in line with demand for chlorine, itself highly influenced by the demand for PVC. Worldwide about 35-40 per cent of the chlorine manufactured is used to make PVC. Demand for PVC is, to a large extent, driven by construction activity and infrastructure investment.
Both chlorine and caustic soda are fundamental to the manufacture of a wide range of modern materials. Caustic soda demand is largely taken up by aluminum production, wood pulping for paper production and soap making.
In Australia, about 60 per cent of the chemical manufacturing industry involves the direct use of chlorine but almost all chemical manufacturing relies indirectly on chlorine or chlorine products.
Most modern building materials – metals and plastics – would be hard-placed to exist without the chlor-alkali industry.
In recent times, the role of chlorine as a feedstock in manufacturing has been criticised because of the potential for emissions of a very reactive substance. Environmental group, Greenpeace, has also called for the phasing out of all synthetic chlorine in the past. Its campaign against chlorine led to it targeting the PVC industry, as the single largest use of chlorine worldwide.
It is known that some organochlorine compounds, such as Chlorofluorocarbons (CFCs), have caused significant global environmental concerns. Yet some forms and uses of chlorine chemistry have provided enormous public health advances, such as chlorination of drinking water and use of PVC pipes. PVC resin is in fact a very stable, virtually inert compound.
Many authorities and expert professional associations have issued statements of strong support for the benefits of chlorine chemistry to society.
"… 50 scientists from nine countries … noted that calls to ban all uses of chlorine to protect the environment are not supported by a critical review of the scientific evidence. They felt that most chlorine chemicals can be produced and used safely."
[ The Society of Environmental Toxicology and Chemistry, 1994 ]
For more detailed information on the properties of chlorine, visit the American Chemistry/Chlorine Chemistry Division website www.americanchemistry.com
Vinyl chloride was first produced in 1835 but did not go into regular production until the early twentieth century. Vinyl chloride has been used in the past as an anaesthetic and as an aerosol spray propellant but its principle use has been to produce the polymer, polyvinyl chloride (PVC), or vinyl.
Today, vinyl chloride monomer (VCM) is produced as a intermediate chemical by the process of either hydrochlorination of acetylene, or the dehydrochlorination of ethylene dichloride (EDC). Refer to the section Manufacturing Process for more detail.
In the early years of PVC production, workers were exposed to potentially very high concentrations of vinyl chloride. In the late 1960s-early 1970s, industry physicians became aware of a small number of workers contracting a rare form of liver cancer, angiosarcoma of the liver (ASL) and suspected an occupational link. Industry collaborated to share information and made public its concerns.
By the mid 1970s, industry and scientific studies confirmed prolonged, high-level exposure to VCM among PVC production workers may cause ASL. Radical changes to technology and processes were then rapidly introduced to protect the health of workers and regulatory exposure standards were made significantly more stringent to reduce risk of exposures and emissions.
Now, all activities involving VCM take place in sealed vessels ensuring production is a closed process. This minimises potential worker exposure, reduces environmental emissions and maximises production efficiencies.
Approximately 230 VCM-related ASL deaths have been recorded worldwide as a result of PVC production over the past 60 years. There has been one death in Australia. The worker was employed at a New South Wales production site at Botany, now closed.
No case of angiosarcoma has been identified in any PVC production worker employed after the introduction of the revised processing technology and exposure standards in the mid to late 1970s.
No member of the general public is known to have suffered any harmful effect from VCM.
Australia’s only PVC manufacturer is located in Victoria and the company complies with the emissions requirements of the State Environment Protection Policy (The Air Environment), the Australian Safety and Compensation Commission and WorkSafe Australia. VCM levels in the workplace are well under the safe exposure levels recommended by Australian regulatory authorities. The company also complies with the industry's voluntary PVC Stewardship Program commitment that sets a stringent standard for maximum emissions of vinyl chloride.
Manufacturing polyvinyl chloride (PVC) is a three-step process, described below. Alternatively, watch our short video for an overview of the process and the manufacturing supply chain.
Step 1 - Producing ethylene dichloride (C2H4Cl2)
Chlorine is extracted from sea salt via electrolysis, and ethylene is derived from hydrocarbon raw materials. These are reacted to produce ethylene dichloride (1,2-dichloroethane).
C2H4 + Cl2 = C2H4Cl2
ethylene + chlorine = ethylene dichloride
Step 2 - Producing Vinyl Chloride Monomer (VCM)
The ethylene dichloride is then decomposed by heating in a high temperature furnace or reactor.
C2H4Cl2 = C2H3Cl + HCl
ethylene dichloride = vinyl chloride monomer + hydrogen chloride
The hydrogen chloride is reacted with more ethylene in the presence of oxygen (a reaction known as oxychlorination). This produces further ethylene dichloride. The resultant ethylene dichloride is decomposed according to the above equation, and the hydrogen chloride is again returned for oxychlorination.
2HCl + C2H4 + ½ O2 = C2H4Cl2 + H2O
= C2H3Cl + HCl2 + H2O
The overall reaction can be shown by adding together the above equations:
2C2H4 + Cl2 + ½ O2 = 2C2H3Cl +H2O
ethylene + chlorine + oxygen = VCM + water
Step 3 - Manufacturing polyvinyl chloride (PVC)
PVC is made using a process called addition polymerisation. This reaction opens the double bonds in the vinyl chloride monomer (VCM) allowing neighbouring molecules to join together creating long chain molecules.
nC2H3Cl = (C2H3Cl)n
vinyl chloride monomer = polyvinylchloride
Polyvinyl chloride (PVC, or vinyl) is one of many different types of plastics. Characteristics of plastics vary according to need for flexibility, transparency, weight, thickness and colour.
PVC is produced in a polymerisation process whereby monomers of vinyl chloride are linked together to form long polymer chains. (See the section Manufacturing for more information on the process.)
All plastics can be grouped into two main polymer families:Thermoplastics (soften on heating and harden again on cooling) and Thermosets (never soften once they have been moulded). PVC is a thermoplastic. One of the benefits of this is that it can be recycled.
Vinyl is one of the most common plastics in the world because of its versatility. Most of us use it everyday. Not only can it be made into rigid or flexible products, thick or thin, it can be made as either a coloured or transparent material. Because of its versatility, vinyl has myriad uses in a wide range of industries:
From sporting greatness to sustainable product
The London 2012 Games were billed to be the most sustainable Games ever. PVC fulfilled a number of important roles in the sporting stadia, as well as being used in sports equipment and accessories.
The athletes are home, the medals are put away, the crowds have gone, but many of the stadiums and infrastructure are now a permanent part of the London landscape.
More than 142,000 m² of PVC fabric alone was used in Olympic Park (now called Queen Elizabeth Park) and external sites. Infrastructure included PVC pipes and the insulation of electrical cables. Many of the more than 10,000 athletes that participated had PVC sportswear, shoes and sports bags; and PVC canopies, mats, padding and barriers protected both athletes and game spectators.
Reviewing the implementation of its PVC Policy applied to procurement and construction of the facilities, the Olympic Development Authority found that the functional properties of PVC made it the most appropriate material in certain circumstances, and sometimes for health and safety reasons, the only solution.
New and innovative applications of PVC were used in venues, equipment and accessories under carefully implemented policies for use, re-use and sustainable practices. Two such venues were the Velodrome and the Shooting Ranges.
The Velodrome was designed with the aim of creating the world’s fastest cycling track by tailoring the track geometry and setting the temperature and environmental conditions within the venue to create record-breaking conditions. To help achieve this, PVC-coated polyester mesh screen wrapped around the whole bowl, varying in height and gradient as it filled the void between the 6000 seats and the curved roof.
The fabric was stretched on a slope from the back edge of each rank of the upper tier seating up to the structural steel ring beam that supports the roof. The hyperbolic paraboloid-shaped building was designed to be lightweight and efficient to reflect the efficient design of a bicycle. The use of abundant daylight through strategically positioned roof lights aimed to reduce the need for artificial lighting, and natural ventilation was achieved through openings in the external timber cladding of the venue.
At the Shooting Ranges located at the famous Royal Artillery Barracks in Woolwich, around 18,000 square metres of PVC membranes were used, giving the enclosures a unique appearance. Vibrantly coloured openings that helped break-up the white facades created the tension, in addition to providing natural ventilation and light.
Recyclable, Reuseable PVC
After the London event, all temporary structures are being dismantled and recycled. A system of crushing, selective dissolving, fibre separation, PVC precipitation and solvent regeneration will ensure that the recycled PVC compound is of a high quality and can be reused with minimum impact on the environment.
Some of the recycled PVC from London 2012 was planned to be used in football stadiums in Brazil for the 2014 FIFA World Cup and the Rio de Janeiro 2016 Games continuing a sustainable product chain to the next great world sporting events.
|SITE||DURING LONDON 2012 GAMES||AFTER LONDON 2012 GAMES|
|Olympic Stadium||25,500m² canopy of white PVC coated polyester fabric covering two-thirds of the spectator seating. The stadium received the Royal Institute of British Architects award as a structure making the greatest contribution to British architecture in the past year.||Stadium size will be reduced and serve as a venue for cultural, community and sporting events.|
|Basketball Arena||This temporary venue uses 20,000m² of recyclable white PVC membrane stretched over three arched panels.||After use during the Paralympics, the arena will be dismantled and the PVC with be re-used at other sporting events.|
|Water Polo Arena||Featuring silver wrap and roof made of inflated PVC cushions for extra insulation and to prevent condensation.||This temporary stadium will be taken down and reassembled elsewhere in the UK.|
|Velodrome||PVC coated polyester mesh screen fabric around the whole bowl. 2,600m² of PVC in high performance surface.||The venue will become a community facility after the Games.|
|Olympic Shooting Gallery||Structure clad with 18,000m2 of PVC membrane.||All materials will be re-used and recycled, the structures to be utilized for the 2014 Commonwealth Games in Glasgow, Scotland.|
|Aquatics Centre||19,000 m² of PVC for a wave-like roof over the interior stands.||Following the Olympics, two temporary wings using PVC will be removed and recycled, the facility will then be open to the local community, clubs and schools.|
|Eton Manor||7,200 m²of PVC membrane covering training pools for aquatic events and hosting wheelchair tennis.||It will house the Olympic Hockey Centre.|
The following animated video from the British Plastics Federation's Vinyls Group explains the use of PVC products in the construction of sporting venues, as well as the diverse range of PVC product applications for performance sports surfaces, sports equipment and clothing.
Plastic is increasingly an integral part of modern cars. Any brand would be challenged to manufacture a modern car which doesn’t contain some plastic elements. In fact, the European Council of Vinyl Manufacturers (ECVM) estimates that around 150kg of plastics are used within an average vehicle.
The attraction of plastics
Building today’s cars requires high performing materials, which help protect occupants, produce cheaper, cleaner and more energy efficient vehicles and last the life of the car, typically 10-15 years. Plastics, including soft PVC in particular, have played a very significant role in light-weighting and improving performance and efficiency.
The British Plastics Federation has calculated that every 100kg of plastic (including PVC) can replace between 200-300 kg of traditional materials. Over the average lifespan of a vehicle, these 100kg of plastics will reduce fuel consumption by 750 litres and consequently, the CO2 emissions.
Nowadays, an average European car contains around 16 kilograms of PVC compound material, which can above all be found in car interiors, underbody protection, joint seals, door panels and cables. EFTEC, one of the world’s largest polymer components manufacturers for the automotive industry, explains the extensive use of PVC in automobiles.
“PVC is being used in many applications that users don’t often think about but which are essential to modern vehicles’ comfort and performance, as well as optimising the car body by reducing weight. For example, layers of flexible vinyl are used for stonechip-protection, sound damping, as sealants, as well as in protective coatings to cover widely exposed areas such as underbodies, wheel arches and rocker panels.
“Automobiles can last much longer and that is, in part, due to the use of this type of flexible PVC which helps to minimise the effects of weather, road and driving conditions.”
Back in the 1990s, a number of car-makers announced moves to distance themselves from PVC use, often because of perceptions of recycling difficulties. However, after more than a decade of exploring alternatives, many manufacturers have realised that replacing PVC may led to inferior performance and higher costs.
Typical PVC automotive components found in use today include instrument panels and associated mouldings, sun visors, synthetic leather seat coverings, headlinings, seals, mud flaps, noise and vibration reduction components, floor coverings, exterior side moulding and protective strips.
PVC's attributes for automotive applications include:
PVC compounds used in vehicles offer excellent cost-performance advantages. A recent study by the independent industrial services consultancy Mavel Consultants, demonstrated the cost of using alternative materials to PVC would be in the range of 20-100% higher per component.
Recycling is an important aspect for end-of-life vehicles. Previously, concerns have been raised about the feasibility of recycling PVC from end-of-life vehicles. However, according to Autovinyle’s data, decomposition trials done by R&D specialists at INDRA confirmed that about 30% of PVC can be economically recovered for recycling, mainly from flexible PVC parts found in interiors.
Other benefits of PVC in cars include:
Child safety is a high priority for all concerned. PVC toys are considered safe because they are hygienic, durable, do not break and are easy to clean.
PVC toys have been used safely for decades, and are in many cases considered much safer than the products they replaced. PVC is used in up to 40 per cent of toys sold in Australia. However, there is relatively little toy manufacturing in Australia as most toys are imported.
To make PVC flexible - for example, for use in soft toys - plasticisers are added. A number of different products are used as plasticisers including categories of chemicals known as orthophthalates (or phthalate esters), citrates and adipates.
The inclusion of orthophthalates in toys sold in Australia is regulated through the Australian Standards AS 8124 (the Toy Standard) and AS2070 (Plastic Materials for food contact use). The safety of toys falls under the jurisdiction of Federal and State departments which deal with matters of public health and safety.
The use of diethylhexyl phthalate (DEHP) as a plasticiser in toys and childcare articles placed on the market in Australia is effectively prohibited. The Australian regulatory authority, the National Industrial Chemicals Notification and Assessment Scheme (NICNAS) recommended a ban on any of these products that contain more than 1% by weight of DEHP after completing a Risk Assessment in 2010. Largely precautionary as DEHP is not expected to be found in toys on the Australian market, the ban relates to toys, childcare articles where significant mouth contact may occur and vessels and eating utensils for feeding infants containing more than one per cent DEHP.
NICNAS also conducted risk assessments for 8 other common orthophthalates used in Australia, with a specific focus on sensitive end uses - toys, childcare articles and cosmetics. Its 2012 assessment of high molecular weight orthophthalate, DINP found that "current risk estimates do not indicate a health concern from exposure of children to DINP in toys and childcare articles even at the highest (reasonable worst-case) exposure scenario considered."
"No recommendations to public health risk management for the use of DINP in toys and child care articles are required based on the findings of this assessment," concluded NICNAS. There are currently no restrictions on the use of DINP in products in Australia.
The scientific assessment team also looked at cumulative exposure of children to DINP and another orthophthalate, and found no significant cause for concern.
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PVC, or vinyl, can be shaped by heat. Extrusion, injection, blow moulding and calendering are just some of the fabrication methods used to make packages such as film for food wrap, blister packs for tablets, clear bottles for cordial and vegetable oils, punnets for fruit and vegetables and clam shell casing to protect electronic goods in transit.
PVC has good printability as film; excellent transparency, an ability to seal and sterilise and the ability to blow an integral handle for transparent bottles. It also has good gas transmission, important for some food products.
Many forms of plastic packaging, including PVC, can be recycled. Learn more about recycling.
PVC food contact film
Plasticised PVC film contributes to food safety, both protecting and preserving food. PVC film is successfully used as vacuum packaging for many fresh products including meat and pre-cooked meals. At home, in supermarkets and in catering establishments, food wrap is a widely-used means of food storage and protection.
Some of the many advantages of plasticised PVC cling films include:
In terms of disposal, most plastics including PVC can be recycled once separated, however, recycling cling wrap after it has been in contact with food is difficult.
Industry Voluntary Commitment
PVC film is a softened, or plasticised material. During manufacture, plasticiser chemicals are added to the PVC resin to provide the flexibility in the final product. In Australia, manufacturers are required by the Food Standards Code to ensure food in contact with packaging is safe. To protect consumers, Standard 1.4.1 - Contaminants and Natural Toxicants sets out the maximum levels of some contaminants that may be present in food as a result of contact with packaging material.
To further reduce consumer concerns, manufacturers of PVC food contact packaging films who are signatories to the Australian industry's PVC Stewardship Program commit to avoid the use of ortho-phthalates - a particular group of plasticiser chemicals - in PVC food contact packaging film supplied to the Australian market because of consumer concern about these substances. Signatories to the voluntary commitment are required to report annually to the Vinyl Council on the use of safe and sustainable additives and are periodically audited under the PVC Stewardship Program.
This voluntary commitment in effect tightens the Australian Standard for Plastics and Food Contact AS 2070 (1999), the standard with which all Australian-made films comply.