Plastic recycling
Plastic recycling is the processing of plastic waste into other products. Recycling can reduce dependence on landfills, conserve resources and protect the environment from plastic pollution and greenhouse gas emissions. Recycling rates lag behind those of other recoverable materials, such as aluminium, glass and paper. From the start of plastic production through to 2015, the world produced around 6.3 billion tonnes of plastic waste, only 9% of which has been recycled and only ~1% has been recycled more than once. Of the remaining waste, 12% was incinerated and 79% was either sent to landfills or released into the environment as pollution.
Almost all plastic is non-biodegradable and without recycling, spreads across the environment where it causes plastic pollution. For example, as of 2015, approximately 8 million tonnes of waste plastic enters the oceans annually, damaging oceanic ecosystems and forming ocean garbage patches.
Almost all recycling is mechanical and involves the melting and reforming of plastic into other items. This can cause polymer degradation at the molecular level, and requires that waste be sorted by colour and polymer type before processing, which is often complicated and expensive. Errors can lead to material with inconsistent properties, rendering it unappealing to industry. Though filtration in mechanical recycling reduces microplastic release, even the most efficient filtration systems cannot prevent the release of microplastics into wastewater.
In feedstock recycling, waste plastic is converted into its starting chemicals, which can then become fresh plastic. This involves higher energy and capital costs. Alternatively, plastic can be burned in place of fossil fuels in energy recovery facilities, or biochemically converted into other useful chemicals for industry. In some countries, burning is the dominant form of plastic waste disposal, particularly where landfill diversion policies are in place.
Plastic recycling is low in the waste hierarchy, meaning that reduction and reuse are more favourable and long-term solutions for sustainability.
It has been advocated since the early 1970s, but due to economic and technical challenges, did not impact the management of plastic waste to any significant extent until the late 1980s.
History
Although plastics were discovered before the 20th century, large-scale production was not realised until World War II. Nylon replaced silk in parachutes, while Perspex was a light-weight alternative to glass in aeroplanes. After the war these materials were commercialized. The plastic age began around 1950, part of the post-war economic boom.Global environmental movements in the 1960s and 1970s led to the formation of environmental agencies in the US, EU Australia and Japan. Environmental awareness put plastic waste under scrutiny. The earliest effort to abate plastic pollution was arguably the 1973 and 1978 MARPOL agreements, whose Annex V banned dumping plastics in the oceans.
Industry lobbying
As regulations expanded, the plastics industry responded with lobbying to preserve their business interests. In the U.S., the 1970 Resource Recovery Act directed the nation towards recycling and energy recovery. More than a thousand attempts to pass legislation to ban or tax packaging, including plastics, came by 1976. The plastics industry responded by lobbying for plastic to be recycled. A $50 million per year campaign was run by organisations such as Keep America Beautiful with the message that plastic could and would be recycled, as well as lobbying for the establishment of curbside recycling.However, plastic could not be economically recycled using the technology of the time. For example, an April 1973 report written by industry scientists stated that, "There is no recovery from obsolete products" and that, "A degradation of resin properties and performance occurs during the initial fabrication, through aging, and in any reclamation process." The report concluded that sorting the plastic is "infeasible". Contemporary scientific reports highlighted numerous technical barriers.
Globally, plastic waste was almost entirely disposed of via landfill until the 1980s when rates of incineration increased. Although better technology was known, these early incinerators often lacked advanced combustors or emission-control systems, leading to the release of dioxins and dioxin-like compounds.
In the late 1980s plastic recycling began in earnest. In 1988 the U.S. Society of the Plastics Industry created the Council for Solid Waste Solutions as a trade association to promote the idea of plastic recycling to the public. The association lobbied American municipalities to launch or expand plastic waste collection programmes and lobbied U.S. states to require the labelling of plastic containers and products with recycling symbols.
The industry introduced resin identification codes in 1988, which provided a standard system for the identification of various polymer types at materials recovery facilities.
Global recycling trade
during the 1990s included the export of plastic waste from advanced economies to developing and middle-income ones, where it could be sorted and recycled less expensively. The annual trade in plastic waste increased rapidly from 1993 onwards as part of the global waste trade.Many governments count items as recycled if they have been exported for that purpose, regardless of the actual outcome. The practice has been labeled environmental dumping, as environmental laws and enforcement are generally weaker in less developed economies. By 2016 about 14 Mt of plastic waste was exported, with China taking 7.35 Mt. Much of this was low quality mixed plastic that ended up in landfills. However, recycled plastic is used extensively in manufacturing in China, and imported plastic waste was predominantly processed using low-technology processing. High-income countries such as Germany, Japan, the United Kingdom and the United States were the top exporters.
In 2017, China began restricting waste plastics imports via Operation National Sword. Exporters eventually exported to other countries mostly in Southeast Asia, such as Vietnam and Malaysia, but also Turkey and India. Indonesia, Malaysia, and Thailand reacted to illegal plastic waste imports by reinforcing border controls. Illegally imported containers were repatriated or refused entry. Consequently, plastic waste containers accumulated in ports.
Given limited export options, attention turned to local solutions. Proposed extended producer responsibility would tax plastic producers to subsidise recyclers.
In 2019, international trade in plastic waste became regulated under the Basel Convention. Under the convention, any Party can decide to prohibit imports of hazardous plastic waste and, since 1 January 2021, of some mixed plastic wastes. Parties to the convention are required to ensure environmentally sound management of their refuse either through alternative importers or by increasing capacity.
The COVID-19 pandemic temporarily reduced trade in plastic waste, due in part to reduced activity at waste management facilities, shipping disruptions, and low oil prices that reduced the cost of virgin plastic and made recycling less profitable.
European Union strategic developments
The European Commission's "Action Plan" for a circular economy, adopted in December 2015, saw plastics as a strategic priority for developing circular economy actions. In 2017, the Commission further adopted a focus on plastic production and use, targeting the achievement of all plastic packaging being recyclable by 2030. The Commission then issued a strategic document in January 2018 which set out an "ambitious vision" and an opportunity for global action on plastic recycling.Production and recycling rates
The total amount of plastic ever produced worldwide, until 2015, is estimated to be 8.3 billion tonnes. Approximately 6.3 Bt of this was discarded as waste, of which around 79% accumulated in landfills or the natural environment, 12% was incinerated, and 9% was recycled - only ~1% of all plastic has been recycled more than once. More recently, as of 2017, still only 9% of the 9 Bt of plastic produced was recycled.By 2015 global production had reached some 381 million tonnes per year. The recycling rate that year was 19.5%, while 25.5% was incinerated and the remaining 55% disposed of, largely to landfill. These rates lag behind those of other recyclables, such as paper, metal and glass. Although the percentage of recycled or incinerated material is increasing each year, the tonnage of waste left-over also continues to rise. Production could reach ~800 Mt per year by 2040, although implementing all feasible interventions could reduce plastic pollution by 40% from 2016 rates.
Recycling rates vary among types of plastic. Several types are in common use, each with distinct chemical and physical properties. This affects sorting and reprocessing costs; which affects the value and market size for recovered materials. PET and HDPE have the highest recycling rates, whereas polystyrene and polyurethane are rarely recycled.
One of the reasons for low levels of plastic recycling is weak demand, given the materials' poor/inconsistent properties. The percentage of plastic that can be fully recycled, rather than downcycled or go to waste, can be increased when manufacturers minimise mixing of packaging materials and eliminate contaminants. The Association of Plastics Recyclers has issued a "Design Guide for Recyclability".
The most commonly produced plastic consumer products include packaging made from LDPE, containers made from HDPE, and PET. Together these products account for around 36% of plastic production. The use of plastics in building and construction, textiles, transportation and electrical equipment accounts for another substantial share of the plastics market.