View source for Chemistry:Plastic

{{short description|Material of a wide range of synthetic or semi-synthetic organic solids}}
{{pp-semi-indef}}
[[File:Plastic household items.jpg|thumb|Household items made of various types of plastics]]

'''Plastics''' are a wide range of synthetic or semi-synthetic materials that use [[Chemistry:Polymer|polymer]]s as a main ingredient. Their [[Physics:Plasticity|plasticity]] makes it possible for plastics to be [[Engineering:Injection moulding|moulded]], [[Chemistry:Extrusion|extruded]] or [[Engineering:Compression molding|pressed]] into solid objects of various shapes. This adaptability, plus a wide range of other properties, such as being lightweight, durable, flexible, and inexpensive to produce, has led to its widespread use. Plastics typically are made through human industrial systems. Most modern plastics are derived from [[Chemistry:Petrochemical|fossil fuel-based chemical]]s like [[Chemistry:Natural gas|natural gas]] or [[Chemistry:Petroleum|petroleum]]; however, recent industrial methods use variants made from renewable materials, such as corn or [[Biology:Cotton|cotton]] derivatives.<ref>{{cite web |title=Life Cycle of a Plastic Product |url=http://www.americanchemistry.com/s_plastics/doc.asp?CID=1571&DID=5972 |url-status=dead |archive-url=https://web.archive.org/web/20100317004747/http://www.americanchemistry.com/s_plastics/doc.asp?CID=1571&DID=5972 |archive-date=March 17, 2010 |access-date=July 1, 2011 |website=Americanchemistry.com |language=en}}</ref>

9.2 billion tonnes of plastic are estimated to have been made between 1950 and 2017. More than half this plastic has been produced since 2004. In 2020, 400 million tonnes of plastic were produced.<ref name=":0">{{cite web |last=Environment |first=U. N. |date=October 21, 2021 |title=Drowning in Plastics – Marine Litter and Plastic Waste Vital Graphics |url=http://www.unep.org/resources/report/drowning-plastics-marine-litter-and-plastic-waste-vital-graphics |access-date=March 21, 2022 |website=UNEP - UN Environment Programme |language=en}}</ref> If global trends on plastic demand continue, it is estimated that by 2050 annual global plastic production will reach over 1.1 billion tonnes.

The success and dominance of plastics starting in the early 20th century has caused widespread environmental problems,<ref>{{cite web |date=October 2020 |title=The environmental impacts of plastics and micro-plastics use, waste and pollution: EU and national measures |url=https://www.europarl.europa.eu/RegData/etudes/STUD/2020/658279/IPOL_STU(2020)658279_EN.pdf |website=europarl.europa.eu}}</ref> due to their slow decomposition rate in natural ecosystems. Most plastic produced has not been reused, or is incapable of reuse, either being captured in landfills or persisting in the environment as plastic pollution and [[Earth:Microplastics|microplastics]]. Plastic pollution can be [[Earth:Marine plastic pollution|found in all the world's major water bodies]], for example, creating [[Earth:Garbage patch|garbage patch]]es in all of the world's oceans and contaminating terrestrial ecosystems. Of all the plastic discarded so far, some 14% has been incinerated and less than 10% has been recycled.<ref name=":0" />

In developed economies, about a third of plastic is used in packaging and roughly the same in buildings in applications such as [[Chemistry:Piping|piping]], [[Engineering:Plumbing|plumbing]] or vinyl siding.<ref name="Applications" /> Other uses include automobiles (up to 20% plastic<ref name="Applications" />), furniture, and toys.<ref name="Applications" /> In the developing world, the applications of plastic may differ; 42% of India's consumption is used in packaging.<ref name="Applications" /> In the medical field, polymer implants and other medical devices are derived at least partially from plastic. Worldwide, about 50&nbsp;kg of plastic is produced annually per person, with production doubling every ten years.

The world's first fully synthetic plastic was [[Chemistry:Bakelite|Bakelite]], invented in New York in 1907, by Leo Baekeland,<ref name="Landmark">{{cite web|last1=American Chemical Society National Historic Chemical Landmarks|title=Bakelite: The World's First Synthetic Plastic|url=http://www.acs.org/content/acs/en/education/whatischemistry/landmarks/bakelite.html|access-date=February 23, 2015}}</ref> who coined the term "plastics".<ref name="Edgar and Edgar 2009">{{Cite book | vauthors = Edgar D, Edgar R |url=https://books.google.com/books?id=_9WGar3yxsAC&q=Baekeland+coined&pg=PA11 |title=Fantastic Recycled Plastic: 30 Clever Creations to Spark Your Imagination|publisher=Sterling Publishing Company, Inc. |year=2009 |isbn=978-1-60059-342-0 |via=Google Books}}</ref> Dozens of different types of plastics are produced today, such as [[Chemistry:Polyethylene|polyethylene]], which is widely used in product packaging, and [[Chemistry:Polyvinyl chloride|polyvinyl chloride]] (PVC), used in construction and pipes because of its strength and durability. Many chemists have contributed to the [[Physics:Materials science|materials science]] of plastics, including Nobel laureate [[Biography:Hermann Staudinger|Hermann Staudinger]], who has been called "the father of [[Chemistry:Polymer chemistry|polymer chemistry]]," and Herman Mark, known as "the father of [[Physics:Polymer physics|polymer physics]]".<ref name="Teegarden 2004">{{Cite book | vauthors = Teegarden DM |url=https://books.google.com/books?id=0qFQ5OuKoy8C&q=%22father+of+polymer%22&pg=PA58 |title=Polymer Chemistry: Introduction to an Indispensable Science |publisher=NSTA Press |year=2004 |isbn=978-0-87355-221-9 |via=Google Books}}</ref>

==Etymology==
The word ''plastic'' derives from the Greek πλαστικός (''plastikos'') meaning "capable of being shaped or [[Engineering:Molding (process)|molded]]," and in turn from πλαστός (''plastos'') meaning "molded."<ref>{{cite web |title=Plastikos |script-title=el:πλαστι^κ-ός |url=https://www.perseus.tufts.edu/cgi-bin/ptext?doc=Perseus%3Atext%3A1999.04.0057%3Aentry%3D%2383506 |access-date=July 1, 2011 |website=Henry George Liddell, Robert Scott, A Greek-English Lexicon}}</ref> As a noun the word most commonly refers to the solid products of petrochemical-derived manufacturing.<ref>{{cite web |title=Plastic |url=https://www.etymonline.com/search?q=plastic |access-date=July 29, 2021 |website=Online Etymology Dictionary}}</ref>

The noun ''plasticity'' refers specifically here to the deformability of the materials used in the manufacture of plastics. Plasticity allows [[Engineering:Molding (process)|molding]], extrusion or [[Engineering:Compression molding|compression]] into a variety of shapes: films, fibers, plates, tubes, bottles and boxes, among many others. [[Physics:Plasticity|Plasticity]] also has a technical definition in materials science outside the scope of this article referring to the non-reversible change in form of solid substances.

== Structure ==
{{See also|Polymer}}Most plastics contain [[Chemistry:Organic compound|organic]] polymers.<ref>{{Cite book|url=https://books.google.com/books?id=BnccCgAAQBAJ&q=most+plastics+contain+organic+compounds&pg=PA52|title=General Chemistry| vauthors = Ebbing D, Gammon SD |date=2016|publisher=Cengage Learning|isbn=978-1-305-88729-9|language=en}}</ref> The vast majority of these polymers are formed from chains of carbon atoms, with or without the attachment of oxygen, nitrogen or sulfur atoms. These chains comprise many [[Chemistry:Repeat unit|repeating units]] formed from [[Chemistry:Monomer|monomer]]s. Each polymer chain consists of several thousand repeating units. The [[Chemistry:Backbone chain|backbone]] is the part of the chain that is on the ''main path'', linking together a large number of repeat units. To customize the properties of a plastic, different molecular groups called side chains hang from this backbone; they are usually hung from the monomers before the monomers themselves are linked together to form the polymer chain. The structure of these side chains influences the properties of the polymer.

==Properties and classifications==
Plastics are usually classified by the chemical structure of the polymer's backbone and side chains. Important groups classified in this way include the acrylics, [[Chemistry:Polyester|polyester]]s, silicones, polyurethanes, and halogenated plastics. Plastics can be classified by the chemical process used in their synthesis, such as [[Chemistry:Condensation reaction|condensation]], [[Chemistry:Polyaddition|polyaddition]], and [[Chemistry:Cross-link|cross-link]]ing.<ref>{{cite web |title=Classification of Plastics |url=http://dwb.unl.edu/Teacher/NSF/C06/C06Links/qlink.queensu.ca/~6jrt/chem210/Page3.html |archive-url=https://web.archive.org/web/20071215124919/http://dwb.unl.edu/Teacher/NSF/C06/C06Links/qlink.queensu.ca/~6jrt/chem210/Page3.html |archive-date=December 15, 2007 |access-date=July 1, 2011 |website=Joanne and Steffanie's Plastics Web Site |language=en}}</ref> They can also be classified by their physical properties, including [[Physics:Hardness|hardness]], [[Physics:Density|density]], [[Physics:Tensile strength|tensile strength]], [[Physics:Thermal resistance|thermal resistance]], and glass transition temperature. Plastics can additionally be classified by their resistance and reactions to various substances and processes, such as exposure to organic solvents, oxidation, and [[Physics:Ionizing radiation|ionizing radiation]].<ref>{{cite web | vauthors = Kent R |title=Periodic Table of Polymers |url=http://www.pcn.org/Technical%20Notes%20-%20Periodic%20Table%20of%20Polymers.htm |archive-url=https://web.archive.org/web/20080703034726/http://www.pcn.org/Technical%20Notes%20-%20Periodic%20Table%20of%20Polymers.htm |archive-date=July 3, 2008 |website=Plastics Consultancy Network |language=en}}</ref> Other classifications of plastics are based on qualities relevant to manufacturing or product design for a particular purpose. Examples include thermoplastics, [[Chemistry:Thermosetting polymer|thermosets]], conductive polymers, biodegradable plastics, [[Engineering:Engineering plastic|engineering plastic]]s and [[Physics:Elastomer|elastomer]]s.

===Thermoplastics and thermosetting polymers===
[[File:Melted plastic.jpg|thumb|upright=0.75|A plastic handle from a kitchen utensil, deformed by heat and partially melted]]
One important classification of plastics is the degree to which the chemical processes used to make them are reversible or not.

Thermoplastics do not undergo chemical change in their composition when heated and thus can be molded repeatedly. Examples include polyethylene (PE), [[Chemistry:Polypropylene|polypropylene]] (PP), [[Chemistry:Polystyrene|polystyrene]] (PS), and polyvinyl chloride (PVC).<ref>{{cite web |title=Composition and Types of Plastic |url=http://www.infoplease.com/ce6/sci/A0860420.html |url-status=dead |website=Infoplease |language=en |access-date=September 29, 2009 |archive-date=October 15, 2012 |archive-url=https://web.archive.org/web/20121015093623/http://www.infoplease.com/ce6/sci/A0860420.html }}</ref>

Thermosets, or thermosetting polymers, can melt and take shape only once: after they have solidified, they stay solid.<ref>{{Cite book | vauthors = Gilleo K  |url=https://books.google.com/books?id=k_2qLoLA_tgC&q=%C2%A0Thermosets,+or+thermosetting+polymers,+can+melt+and+take+shape+only+once |title=Area Array Packaging Processes: For BGA, Flip Chip, and CSP |date=2004 |publisher=McGraw Hill Professional |isbn=978-0-07-142829-3 |language=en |via=Google Books}}</ref> If reheated, thermosets decompose rather than melt. In the thermosetting process, an irreversible chemical reaction occurs. The [[Chemistry:Vulcanization|vulcanization]] of [[Chemistry:Natural rubber|rubber]] is an example of this process. Before heating in the presence of sulfur, natural rubber ([[Chemistry:Polyisoprene|polyisoprene]]) is a sticky, slightly runny material; after vulcanization, the product is dry and rigid.

===Amorphous plastics and crystalline plastics===
Many plastics are completely [[Physics:Amorphous|amorphous]] (without a highly ordered molecular structure),<ref>{{Cite book | vauthors = Kutz M |url=https://books.google.com/books?id=gWg-rchM700C&q=many+plastics+completely+amorphous&pg=PA336 |title=Handbook of Materials Selection |publisher=John Wiley & Sons |year=2002 |isbn=978-0-471-35924-1 |language=en |via=Google Books}}</ref> including thermosets, polystyrene, and methyl methacrylate (PMMA). [[Chemistry:Crystalline|Crystalline]] plastics exhibit a pattern of more regularly spaced atoms, such as high-density polyethylene (HDPE), polybutylene terephthalate (PBT), and polyether ether ketone (PEEK). However, some plastics are partially amorphous and partially crystalline in molecular structure, giving them both a melting point and one or more glass transitions (the temperature above which the extent of localized molecular flexibility is substantially increased). These so-called [[Physics:Crystallization of polymers|semi-crystalline]] plastics include polyethylene, polypropylene, polyvinyl chloride, polyamides (nylons), polyesters and some polyurethanes.

===Conductive polymers===
{{Main|Chemistry:Conductive polymer}}
Intrinsically Conducting Polymers (ICP) are organic polymers that conduct electricity. While a conductivity of up to 80 kS/cm in stretch-oriented [[Chemistry:Polyacetylene|polyacetylene]],<ref>{{Cite journal | vauthors = Heeger AJ, Kivelson S, Schrieffer JR, Su WP |date=1988 |title=Solitons in Conducting Polymers |journal=Reviews of Modern Physics |volume=60 |issue=3 |pages=781–850 |bibcode=1988RvMP...60..781H |doi=10.1103/RevModPhys.60.781}}</ref> has been achieved, it does not approach that of most metals. For example, copper has a conductivity of several hundred kS/cm.<ref>{{cite web |title=Properties of Copper |url=https://copperalliance.org.uk/about-copper/copper-alloys/properties-copper/ |website=Copper Development Association |language=en}}</ref>

===Biodegradable plastics and bioplastics===
====Biodegradable plastics====
{{Main|Chemistry:Biodegradable plastic}}
Biodegradable plastics are plastics that degrade (break down) upon exposure to sunlight or ultra-violet radiation; water or dampness; bacteria; enzymes; or wind abrasion. Attack by insects, such as waxworms and mealworms, can also be considered as forms of biodegradation. [[Engineering:Aerobic digestion|Aerobic]] degradation requires that the plastic be exposed at the surface, whereas [[Physics:Anaerobic digestion|anaerobic]] degradation would be effective in landfill or composting systems. Some companies produce [[Chemistry:Biodegradable additives|biodegradable additives]] to enhance biodegradation. Although starch powder can be added as a filler to allow some plastics to degrade more easily, such treatment does not lead to complete breakdown. Some researchers have [[Biology:Genetic engineering|genetically engineered]] bacteria to synthesize completely biodegradable plastics, such as polyhydroxy butyrate (PHB); however, these are relatively costly as of 2021.<ref>{{Cite journal | vauthors = Brandl H, Püchner P |date=1992 |title=Biodegradation Biodegradation of Plastic Bottles Made from 'Biopol' in an Aquatic Ecosystem Under In Situ Conditions |journal=Biodegradation |volume=2 |issue=4 |pages=237–43 |doi=10.1007/BF00114555 |s2cid=37486324}}</ref>

====Bioplastics====
{{Main|Chemistry:Bioplastic}}
While most plastics are produced from petrochemicals, bioplastics are made substantially from renewable plant materials like cellulose and starch.<ref>{{cite web|url=http://www.nnfcc.co.uk/tools/biochemical-opportunities-in-the-uk-nnfcc-08-008 |title=Biochemical Opportunities in the UK, NNFCC 08-008 — NNFCC |access-date=March 24, 2011 |url-status=dead |archive-url=https://web.archive.org/web/20110720183608/http://www.nnfcc.co.uk/tools/biochemical-opportunities-in-the-uk-nnfcc-08-008 |archive-date=July 20, 2011 }}</ref> Due both to the finite limits of fossil fuel reserves and to [[Earth:Climate change|rising levels of greenhouse gases]] caused primarily by the burning of those fuels, the development of bioplastics is a growing field.<ref>{{cite web|url=https://packagingeurope.com/bioplastics-growth-report/#:~:text=Packaging%20remains%20the%20largest%20field,total%20bioplastics%20market%20in%202019.&text=According%20to%20the%20report%2C%20global,2.4%20million%20tonnes%20in%202024.|title=Bioplastics industry shows dynamic growth|date=December 5, 2019}}</ref><ref>{{cite web|url=https://www.bioplasticsmagazine.com/en/news/meldungen/20181130-becoming-employed.php|title=Becoming Employed in a Growing Bioplastics Industry - bioplastics MAGAZINE|website=www.bioplasticsmagazine.com}}</ref> Global production capacity for bio-based plastics is estimated at 327,000 tonnes per year. In contrast, global production of polyethylene (PE) and polypropylene (PP), the world's leading petrochemical-derived polyolefins, was estimated at over 150 million tonnes in 2015.<ref>{{cite news| vauthors = Galie F |title=Global Market Trends and Investments in Polyethylene and Polyproplyene|url=https://www.icis.com/globalassets/documents/forms/ppf-pdf/global_trends_whitepaper_pp_pe.pdf|access-date=December 16, 2017|work=ICIS Whitepaper|publisher=Reed business Information, Inc.|date=November 2016}}</ref>

==Plastic industry==
The plastic industry includes the global production, compounding, conversion and sale of plastic products. Although the [[Place:Middle East|Middle East]] and {{wipe|Russia}} produce most of the required [[Chemistry:Petrochemical|petrochemical]] raw materials; the production of plastic is concentrated in the global East and West. The plastic industry comprises a huge number of companies and can be divided into several sectors:

===Production===
Between 1950 and 2017, 9.2 billion tonnes of plastic are estimated to have been made, with more than half this having been produced since 2004. Since the birth of the plastic industry in the 1950s, global production has increased enormously, reaching 400 million tonnes a year in 2021; this is up from 381 million metric tonnes in 2015 (excluding additives).<ref name=":0" /><ref name=Geyer2017>{{cite journal |last1=Geyer |first1=Roland |last2=Jambeck |first2=Jenna R. |last3=Law |first3=Kara Lavender |title=Production, use, and fate of all plastics ever made |journal=Science Advances |date=July 2017 |volume=3 |issue=7 |pages=e1700782 |doi=10.1126/sciadv.1700782  |pmid=28776036 |pmc=5517107 |bibcode=2017SciA....3E0782G |doi-access=free}}</ref> From the 1950s, rapid growth occurred in the use of plastics for packaging, in building and construction, and in other sectors.<ref name=":0" /> If global trends on plastic demand continue, it is estimated that by 2050 annual global plastic production will exceed 1.1 billion tonnes annually.<ref name=":0" />

{{multiple image
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 | image1 = Slovnaft - new polypropylene plant PP3.JPG
 | alt1 = A Slovnaft facility in Bratislava, Slovakia
 | caption1 = A Slovnaft facility in [[Place:Bratislava|Bratislava]], Slovakia
 | image2 = Ilham Aliyev, Italian President Sergio Mattarella attended inauguration of polypropylene plant constructed in Sumgayit Chemical Industrial Park under SOCAR Polymer project 32.jpg
 | alt2 = A SOCAR Polymer polypropylene plant in Sumgayit, Azerbaijan 
 | caption2 = A SOCAR Polymer polypropylene plant in Sumgayit, [[Place:Azerbaijan|Azerbaijan]]
}}
{{Image frame 
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 | caption=Annual global plastic production 1950–2015.<ref name=Geyer2017 /> Vertical lines denote the 1973–1975 recession and the [[Finance:Financial crisis of 2007–2008|financial crisis of 2007–2008]] which caused brief lowering of plastic production.
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 | x=1950,1951,1952,1953,1954,1955,1956,1957,1958,1959,1960,1961,1962,1963,1964,1965,1966,1967,1968,1969,1970,1971,1972,1973,1974,1975,1976,1977,1978,1979,1980,1981,1982,1983,1984,1985,1986,1987,1988,1989,1990,1991,1992,1993,1994,1995,1996,1997,1998,1999,2000,2001,2002,2003,2004,2005,2006,2007,2008,2009,2010,2011,2012,2013,2014,2015
 | y=2,2,2,3,3,4,5,5,6,7,8,9,11,13,15,17,20,23,27,32,35,38,44,51,52,46,54,59,64,71,70,72,73,80,86,90,96,104,110,114,120,124,132,137,151,156,168,180,188,202,213,218,231,241,256,263,280,295,281,288,313,325,338,352,367,381
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{{clear}}
Plastics are produced in chemical plants by the [[Chemistry:Polymerization|polymerization]] of their starting materials (monomers); which are almost always [[Chemistry:Petrochemical|petrochemical]] in nature. Such facilities are normally large and are visually similar to [[Chemistry:Oil refinery|oil refineries]], with sprawling pipework running throughout. The large size of these plants allows them to exploit [[Finance:Economies of scale|economies of scale]]. Despite this, plastic production  is not particularly monopolized, with about 100 companies accounting for 90% of global production.<ref>{{cite web |title=Top 100 Producers: The Minderoo Foundation |url=https://www.minderoo.org/plastic-waste-makers-index/data/indices/producers/ |website=www.minderoo.org |access-date=October 14, 2021}}</ref> This includes a mixture of private and state-owned enterprises. Roughly half of all production takes place in East Asia, with China being the largest single producer. Major international producers include:

{{align|left|
*Dow Chemical
*[[Company:LyondellBasell|LyondellBasell]]
*Exxonmobil
*SABIC
*BASF
*Sibur
*Shin-Etsu Chemical
*Indorama Ventures
*[[Company:Sinopec|Sinopec]]
*[[Company:Braskem|Braskem]]
}}
{| class="wikitable sortable" style="margin-left: auto"
|+ Global plastic production (2020)<ref name=PlasEU>{{cite web |title=Plastics – the Facts 2020 |url=https://www.plasticseurope.org/application/files/5716/0752/4286/AF_Plastics_the_facts-WEB-2020-ING_FINAL.pdf |url-status=dead |archive-url=https://web.archive.org/web/20211007065614/https://www.plasticseurope.org/application/files/5716/0752/4286/AF_Plastics_the_facts-WEB-2020-ING_FINAL.pdf |archive-date=October 7, 2021}}</ref>
|-
! Region !! Global production
|-
| China || 31%
|-
| Japan || 3%
|-
| Rest of Asia || 17%
|-
| NAFTA || 19%
|-
| Latin America || 4%
|-
| Europe || 16%
|-
| CIS || 3%
|-
| Middle East & Africa || 7%
|}
Historically, [[Earth:Europe|Europe]] and [[Earth:North America|North America]] have dominated global plastics production. However, since 2010 Asia has emerged as a significant producer, with {{wipe|China}} accounting for 31% of total plastic resin production in 2020.<ref name=PlasEU /> Regional differences in the volume of plastics production are driven by user demand, the price of fossil fuel feedstocks, and investments made in the petrochemical industry. For example, since 2010 over US$200&nbsp;billion has been invested in the United States in new plastic and chemical plants, stimulated by the low cost of raw materials. In the [[Social:European Union|European Union]] (EU), too, heavy investments have been made in the plastics industry, which employs over 1.6 million people with a turnover of more than 360 billion euros per year. In China in 2016 there were over 15,000 plastic manufacturing companies, generating more than US$366&nbsp;billion in revenue.<ref name=":0" />

In 2017, the global plastics market was dominated by [[Chemistry:Thermoplastic|thermoplastic]]s– polymers that can be melted and recast. Thermoplastics include [[Chemistry:Polyethylene|polyethylene]] (PE), [[Chemistry:Polyethylene terephthalate|polyethylene terephthalate]] (PET), [[Chemistry:Polypropylene|polypropylene]] (PP), [[Chemistry:Polyvinyl chloride|polyvinyl chloride]] (PVC), [[Chemistry:Polystyrene|polystyrene]] (PS) and synthetic fibres, which together represent 86% of all plastics.<ref name=":0" />

===Compounding===
[[File:Compounding-en.png|thumb|right|450px|Plastic compounding scheme for a thermosoftening material]]

Plastic is not sold as a pure unadulterated substance, but is instead mixed with various chemicals and other materials, which are collectively known as additives. These are added during the compounding stage and include substances such as [[Chemistry:Polymer stabilizers|stabilizers]], [[Chemistry:Plasticizer|plasticizer]]s and dyes, which are intended to improve the lifespan, workability or appearance of the final item. In some cases, this can involve mixing different types of plastic together to form a [[Chemistry:Polymer blend|polymer blend]], such as high impact polystyrene. Large companies may do their own compounding prior to production, but some producers have it done by a third party. Companies that specialize in this work are known as Compounders.

The compounding of thermosetting plastic is relatively straightforward; as it remains liquid until it is [[Chemistry:Curing|cured]] into its final form. For thermosoftening materials, which are used to make the majority of products, it is necessary to melt the plastic in order to mix-in the additives. This involves heating it to anywhere between {{Convert|150-320|C|F|round=5}}. Molten plastic is viscous and exhibits [[Physics:Laminar flow|laminar flow]], leading to poor mixing. Compounding is therefore done using extrusion equipment, which is able to supply the necessary heat and mixing to give a properly dispersed product.

The concentrations of most additives are usually quite low, however high levels can be added to create [[Chemistry:Masterbatch|Masterbatch]] products. The additives in these are concentrated but still properly dispersed in the host resin. Masterbatch granules can be mixed with cheaper bulk polymer and will release their additives during processing to give a [[Physics:Homogeneous|homogeneous]] final product. This can be cheaper than working with a fully compounded material and is particularly common for the introduction of colour.

===Converting===
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Companies that produce finished goods are known as converters (sometimes processors). The vast majority of plastics produced worldwide are thermosoftening and must be heated until molten in order to be molded. Various sorts of extrusion equipment exist which can then form the plastic into almost any shape.

*[[Engineering:Film blowing machine|Film blowing]] - Plastic films (carrier bags, sheeting)
*[[Engineering:Blow molding|Blow molding]] - Small thin-walled hollow objects in large quantities (drinks bottles, toys)
*[[Engineering:Rotational molding|Rotational molding]] - Large thick-walled hollow objects ([[Engineering:Intermediate bulk container|IBC tanks]])
*[[Engineering:Injection molding machine|Injection molding]] - Solid objects (phone cases, keyboards) 
*[[Engineering:Spinning (polymers)|Spinning]] - Produces fibers ([[Chemistry:Nylon|nylon]], [[Chemistry:Spandex|spandex]] etc.)

For thermosetting materials the process is slightly different, as the plastics are liquid to begin with and but must be [[Chemistry:Curing|cured]] to give solid products, but much of the equipment is broadly similar.

The most commonly produced plastic consumer products include packaging made from [[Chemistry:Low-density polyethylene|LDPE]] (e.g. bags, containers, food packaging film), containers made from [[Chemistry:High-density polyethylene|HDPE]] (e.g. milk bottles, shampoo bottles, ice cream tubs), and [[Chemistry:Polyethylene terephthalate|PET]] (e.g. bottles for water and other drinks). Together these products account for around 36% of plastics use in the world. Most of them (e.g. disposable cups, plates, cutlery, takeaway containers, carrier bags) are used for only a short period, many for less than a day. The use of plastics in building and construction, textiles, transportation and electrical equipment also accounts for a substantial share of the plastics market. Plastic items used for such purposes generally have longer life spans. They may be in use for periods ranging from around five years (e.g. textiles and electrical equipment) to more than 20 years (e.g. construction materials, industrial machinery).<ref name=":0" />

Plastic consumption differs among countries and communities, with some form of plastic having made its way into most people's lives. North America (i.e. the North American Free Trade Agreement or NAFTA region) accounts for 21% of global plastic consumption, closely followed by China (20%) and Western Europe (18%). In North America and Europe there is high per capita plastic consumption (94&nbsp;kg and 85&nbsp;kg/capita/year, respectively). In China there is lower per capita consumption (58&nbsp;kg/capita/year), but high consumption nationally because of its large population.<ref name=":0" />{{clear}}

==Types of plastics==
===Commodity plastics===
[[File:Plastics Summary.svg|right|250px|thumb|Chemical structures and uses of some common plastics]]

Around 70% of global production is concentrated in six major polymer types, the so-called [[Chemistry:Commodity plastics|commodity plastics]]. Unlike most other plastics these can often be identified by their [[Resin identification code|resin identification code]] (RIC):
:[[File:Symbol Resin Code 01 PET.svg|35px]] [[Chemistry:Polyethylene terephthalate|Polyethylene terephthalate]] (PET or PETE)
:[[File:Symbol Resin Code 02 PE-HD.svg|35px]] [[Chemistry:High-density polyethylene|High-density polyethylene]] (HDPE or PE-HD)
:[[File:Symbol Resin Code 03 PVC.svg|35px]] [[Chemistry:Polyvinyl chloride|Polyvinyl chloride]] (PVC or V)
:[[File:Symbol Resin Code 04 PE-LD.svg|35px]] [[Chemistry:Low-density polyethylene|Low-density polyethylene]] (LDPE or PE-LD),
:[[File:Symbol Resin Code 05 PP.svg|35px]] [[Chemistry:Polypropylene|Polypropylene]] (PP)
:[[File:Symbol Resin Code 06 PS.svg|35px]] [[Chemistry:Polystyrene|Polystyrene]] (PS)

[[Chemistry:Polyurethane|Polyurethane]]s (PUR) and PP&A fibres<ref name=PP&A>PP&A stand for [[Chemistry:Polyester|polyester]], [[Chemistry:Polyamide|polyamide]] and acrylate polymers; all of which are used to make synthetic fibres. Care should be taken not to confuse it with [[Chemistry:Polyphthalamide|polyphthalamide]] (PPA)</ref> are often also included as major commodity classes, although they usually lack RICs, as they are chemically quite diverse groups. These materials are inexpensive, versatile and easy to work with, making them the preferred choice for the [[Finance:Mass production|mass production]] everyday objects. Their biggest single application is in packaging, with some 146 million tonnes being used this way in 2015, equivalent to 36% of global production. Due to their dominance; many of the properties and problems commonly associated with plastics, such as pollution stemming from their poor biodegradability, are ultimately attributable to commodity plastics.

A huge number of plastics exist beyond the commodity plastics, with many having exceptional properties.

{{Clear}}
{{Graph:Chart
 | width=110
 | height=110
 | type=pie
 | legend=Polymer
 | x=LDPE,HDPE,PP,PS,PVC,PET,PUR,PP&A Fibers,All Others,Additives
 | y1=0.157,0.128,0.167,0.061,0.093,0.081,0.066,0.145,0.039,0.061
 | showValues=format:.1%,offset:5
}}

{| class="wikitable sortable" style="width:55em; margin: 1em auto"
|+Global plastic production by polymer type (2015)<ref name=Geyer2017 />
|-
! Polymer !! Production (Mt) !! Percentage of all plastics !! Polymer type !! Thermal character
|- 
|Low-density polyethylene (LDPE) || 64 || 15.7% || Polyolefin || Thermoplastic
|-
|High-density polyethylene (HDPE) || 52 || 12.8% ||Polyolefin || Thermoplastic
|-
|polypropylene (PP) || 68 || 16.7% || Polyolefin || Thermoplastic
|-
|Polystyrene (PS) || 25|| 6.1% || Unsaturated polyolefin || Thermoplastic
|-
|Polyvinyl chloride (PVC) || 38 || 9.3% || Halogenated || Thermoplastic
|-
|Polyethylene terephthalate (PET) || 33 || 8.1% || Condensation || Thermoplastic
|-
|Polyurethane (PUR) || 27 || 6.6% || Condensation || Thermoset<ref>The majority of polyurethanes are thermosets, however some thermoplastics are also produced, for instance [[Chemistry:Spandex|spandex]]</ref>
|-
|PP&A Fibers<ref name=PP&A/> || 59 || 14.5% || Condensation || Thermoplastic 
|-
| All Others || 16 || 3.9% || Various || Varies
|-
| Additives || 25 || 6.1% || - || -
|-
| '''Total''' || '''407''' || '''100%''' || - || -
|}

===Engineering plastics===
[[Engineering:Engineering plastic|Engineering plastic]]s are more robust and are used to make  products such as vehicle parts, building and construction materials, and some machine parts. In some cases they are [[Chemistry:Polymer blend|polymer blend]]s formed by mixing different plastics together (ABS, HIPS etc.). Engineering plastics can replace metals in vehicles, lowering their weight and improving fuel efficiency by 6–8%. Roughly 50% of the volume of modern cars is made of plastic, but this only accounts for 12–17% of the vehicle weight.<ref>{{cite web |title=Plastic Recycling Factsheet |url=https://circulareconomy.europa.eu/platform/sites/default/files/euric_-_plastic_recycling_fact_sheet.pdf |publisher=EuRIC - European Recycling Industries’ Confederation |access-date=November 9, 2021}}</ref>

*[[Chemistry:Acrylonitrile butadiene styrene|Acrylonitrile butadiene styrene]] (ABS): electronic equipment cases (e.g. computer monitors, printers, keyboards) and drainage pipe
*High impact polystyrene (HIPS): refrigerator liners, food packaging and vending cups
*[[Physics:Polycarbonate|Polycarbonate]] (PC): compact discs, eyeglasses, [[Engineering:Riot shield|riot shield]]s, security windows, traffic lights, and lenses
*Polycarbonate + acrylonitrile butadiene styrene (PC + ABS): a blend of PC and ABS that creates a stronger plastic used in car interior and exterior parts, and in mobile phone bodies
*Polyethylene + acrylonitrile butadiene styrene (PE + ABS): a slippery blend of PE and ABS used in low-duty dry bearings
*Polymethyl methacrylate (PMMA) (acrylic): contact lenses (of the original "hard" variety), glazing (best known in this form by its various trade names around the world; e.g. Perspex, Plexiglas, and Oroglas), fluorescent-light diffusers, and rear light covers for vehicles. It also forms the basis of artistic and commercial acrylic paints, when suspended in water with the use of other agents.
*[[Chemistry:Silicone|Silicone]]s (polysiloxanes): heat-resistant resins used mainly as sealants but also used for high-temperature cooking utensils and as a base resin for industrial paints
*[[Chemistry:Urea-formaldehyde|Urea-formaldehyde]] (UF): one of the aminoplasts used as a multi-colorable alternative to phenolics: used as a wood adhesive (for plywood, chipboard, hardboard) and electrical switch housings

===High-performance plastics===
[[Chemistry:High-performance plastics|High-performance plastics]] are usually expensive, with their use limited to specialised applications which make use of their superior properties.

*[[Chemistry:Aramid|Aramid]]s: best known for their use in making [[Engineering:Body armor|body armor]], this class of heat-resistant and strong synthetic fibers are also used in aerospace and military applications, includes [[Chemistry:Kevlar|Kevlar]] and [[Engineering:Nomex|Nomex]], and [[Chemistry:Twaron|Twaron]].
*[[Chemistry:Ultra-high-molecular-weight polyethylene|Ultra-high-molecular-weight polyethylene]]s
*Polyetheretherketone (PEEK): strong, chemical- and heat-resistant thermoplastic; its [[Chemistry:Biocompatibility|biocompatibility]] allows for use in medical implant applications and aerospace moldings. It is one of the most expensive commercial polymers.
*[[Chemistry:Polyetherimide|Polyetherimide]] (PEI) (Ultem): a high-temperature, chemically stable polymer that does not crystallize
*[[Chemistry:Polyimide|Polyimide]]: a high-temperature plastic used in materials such as [[Chemistry:Kapton|Kapton]] tape
*[[Chemistry:Polysulfone|Polysulfone]]: high-temperature melt-processable resin used in membranes, filtration media, water heater dip tubes and other high-temperature applications
*[[Chemistry:Polytetrafluoroethylene|Polytetrafluoroethylene]] (PTFE), or [[Engineering:Teflon|Teflon]]: heat-resistant, low-friction coatings used in non-stick surfaces for frying pans, plumber's tape and water slides
*[[Chemistry:Polyamide-imide|Polyamide-imide]] (PAI): High-performance engineering plastic extensively used in high performance gears, switches, transmission and other automotive components, and aerospace parts.<ref>{{cite web |url=https://www.euroshore.com.my/about/industries/aerospace-plastics/ |title=Polymers in aerospace applications |publisher=Euroshore |access-date=June 2, 2021}}</ref>

==Gallery==
<gallery>
PET Bottle Water.jpg|Water bottles made of [[Chemistry:Polyethylene terephthalate|PET]]
Shampoo1.jpg|High density polythene (HDPE) is used for making sturdy containers; transparent containers may be made of PET.
Pulling on the hood of the Tyveck suit (5429334133).jpg|Disposable suits can be made from non-woven HDPE fabric.
Registered Mail Royal Mail - Great Britain-Germany 2017 - envelope front side.jpg|Plastic mailing envelopes made of HDPE
1682478-poster-1280-plasticbags.jpg|Clear plastic bags (shown) are made of low density polythene (LDPE); blown-film shopping bags with handles are now made of HDPE.
A Ziploc bag made from LDPE.jpg|A Ziploc bag made of LDPE
Daujėnų naminė duona.JPG|Food wrap made of LDPE
Image-from-rawpixel-id-5957725-original.jpg|Metalised [[Chemistry:Polypropylene|polypropylene]] film is a commonly used snack pack material.<ref>{{Cite web |date=October 28, 2021 |title=Sustainable packaging materials for snacks |url=https://www.bakeryandsnacks.com/Article/2013/06/06/Sustainable-packaging-materials-for-snacks |access-date=September 10, 2022 |website= |archive-url=https://web.archive.org/web/20211028142046/https://www.bakeryandsnacks.com/Article/2013/06/06/Sustainable-packaging-materials-for-snacks |archive-date=October 28, 2021 |url-status=dead}}</ref>
Kinder Joy 01.jpg|Kinder Joy shell made of polypropylene
Red Polypropylene Chair with Stainless Steel Structure.JPG|A polypropylene chair
Hanoi Vietnam The-omnipresent-plastic-chairs-01.jpg|Stools made of HDPE
Polistirolo.JPG|Expanded [[Chemistry:Polystyrene|polystyrene]] foam ("Thermocol")
Styrofoam-grey-board.jpg|Extruded polystyrene foam ("Styrofoam")
Have a Nice Day! styrofoam food container.JPG|Thermocol take-away food container
Plastic egg carton.jpg|Egg tray made of [[Chemistry:Polyethylene terephthalate|PETE]]
LDPE Foam.jpg|A piece of packaging foam made of LDPE
Urethane sponge1.jpg|A kitchen sponge made of [[Physics:Polyurethane foam|polyurethane foam]]
Frying pan.jpeg|[[Physics:Non-stick surface|Non-stick]] cookware with [[Engineering:Teflon|Teflon]] coating
IPhone 5c blue back.jpg|[[Engineering:IPhone 5C|iPhone 5c]], a smartphone with a [[Physics:Polycarbonate|polycarbonate]] "unibody" shell
KelpAquarium.jpg|To withstand the extreme water pressure, this {{nowrap|10-meter}} deep Monterey Bay Aquarium tank has windows made of acrylic glass up to 33&nbsp;cm thick.
Plastic tubing.jpg|alt=|PVC pipes
Pills in blister pack.jpg|PVC blister pack
</gallery>

==Applications==
The largest application for plastics is as packaging materials, but they are used in a wide range of other sectors, including: construction (pipes, gutters, door and windows), textiles (stretchable fabrics, [[Engineering:Polar fleece|fleece]]), consumer goods (toys, tableware, toothbrushes), transportation (headlights, bumpers, body panels, [[Engineering:Wing mirror|wing mirror]]s), electronics (phones, computers, televisions) and as machine parts.<ref name=Geyer2017 />

{{align|left|
{{Graph:Chart
 | width=600
 | height=300
 | yAxisTitle=Million metric tonnes
 | type=rect
 | x=Packaging,Construction,Other sectors,Textiles,Consumer products,Transportation,Electronics,Industrial Machinery
 | xAxisAngle=+30
 | xAxisTitle=Primary plastic production by industrial sector 2015
 | y1=146
 | y2=,65
 | y3=,,59
 | y4=,,,47
 | y5=,,,,42
 | y6=,,,,,27
 | y7=,,,,,,18
 | y8=,,,,,,,3
 |showValues = offset:4
}}
}}
{{Break|2}}
{{Graph:Chart
 | width=110
 | height=110
 | type=pie
 | x=Packaging,Construction,Other sectors,Textiles,Consumer products,Transportation,Electronics,Industrial Machinery
 | y1=0.358722359,0.15970516,0.144963145,0.115479115,0.103194103,0.066339066,0.044226044,0.007371007
 | showValues=format:.0%,offset:6
}}
{{clear}}

==Additives==
Additives are chemicals blended into plastics to change their performance or appearance, making it possible to alter the properties of plastics to better suit their intended applications.<ref name="Additive-rev">{{cite journal | vauthors = Hahladakis JN, Velis CA, Weber R, Iacovidou E, Purnell P | title = An overview of chemical additives present in plastics: Migration, release, fate and environmental impact during their use, disposal and recycling | journal = Journal of Hazardous Materials | volume = 344 | pages = 179–199 | date = February 2018 | pmid = 29035713 | doi = 10.1016/j.jhazmat.2017.10.014 | doi-access = free }}</ref><ref>{{cite journal |last1=Marturano |first1=Valentina |last2=Cerruti |first2=Pierfrancesco |last3=Ambrogi |first3=Veronica |title=Polymer additives |journal=Physical Sciences Reviews |date=June 27, 2017 |volume=2 |issue=6 |page=130 |doi=10.1515/psr-2016-0130|bibcode=2017PhSRv...2..130M |s2cid=199059895 |doi-access=free }}</ref> Additives are therefore one of the reasons why plastic is used so widely.<ref>{{cite journal |last1=Pfaendner |first1=Rudolf |title=How will additives shape the future of plastics? |journal=Polymer Degradation and Stability |date=September 2006 |volume=91 |issue=9 |pages=2249–2256 |doi=10.1016/j.polymdegradstab.2005.10.017}}</ref> Plastics are composed of chains of polymers. Many different chemicals are used as plastic additives. A randomly chosen plastic product generally contains around 20 additives. The identities and concentrations of additives are generally not listed on products.<ref name=":0" />

In the EU, over 400 additives are used in high volumes.<ref>{{cite web |title=Mapping exercise – Plastic additives initiative - ECHA |url=https://echa.europa.eu/mapping-exercise-plastic-additives-initiative |website=echa.europa.eu |access-date=May 3, 2022}}</ref><ref name=":0" /> 5500 additives were found in a global market analysis.<ref>{{Cite journal |last1=Wiesinger |first1=Helene |last2=Wang |first2=Zhanyun |last3=Hellweg |first3=Stefanie |date=July 6, 2021 |title=Deep Dive into Plastic Monomers, Additives, and Processing Aids |journal=Environmental Science & Technology |volume=55 |issue=13 |pages=9339–9351 |doi=10.1021/acs.est.1c00976|pmid=34154322 |bibcode=2021EnST...55.9339W |hdl=20.500.11850/495854 |s2cid=235597312 |hdl-access=free }}</ref> At a minimum all plastic contains some polymer stabilisers which permit them to be melt-processed (moulded) without suffering [[Chemistry:Polymer degradation|polymer degradation]]. Other additives are optional and can be added as required, with loadings varying significantly between applications. The amount of additives contained in plastics varies depending on the additives’ function. For example, additives in [[Chemistry:Polyvinyl chloride|polyvinyl chloride]] (PVC) can constitute up to 80% of the total volume.<ref name=":0" /> Pure unadulterated plastic (barefoot resin) is never sold, even by the primary producers.

=== Leaching ===
Additives may be weakly bound to the polymers or react in the polymer matrix. Although additives are blended into plastic they remain chemically distinct from it, and can gradually leach back out during normal use, when in landfills, or following improper disposal in the environment.<ref>{{cite web |title=Emission Scenario Documents: N°3 Plastic Additives (2004, revised in 2009) |url=https://www.oecd.org/officialdocuments/publicdisplaydocumentpdf/?cote=env/jm/mono(2004)8/rev1&doclanguage=en |publisher=Organisation for Economic Co-operation and Development |access-date=May 19, 2022}}</ref> Additives may also degrade to form other toxic molecules. Plastic fragmentation into microplastics and nanoplastics can allow chemical additives to move in the environment far from the point of use. Once released, some additives and derivatives may persist in the environment and bioaccumulate in organisms. They can have adverse effects on human health and biota. A recent review by the United States Environmental Protection Agency (US EPA) revealed that out of 3,377 chemicals potentially associated with plastic packaging and 906 likely associated with it, 68 were ranked by ECHA as "highest for human health hazards" and 68 as "highest for environmental hazards".<ref name=":0" />

=== Recycling ===
{{Main|Physics:Plastic recycling}}
As additives change the properties of plastics they have to be considered during recycling. Presently, almost all recycling is performed by simply remelting and reforming used plastic into new items. Additives present risks in recycled products, as they are difficult to remove. When plastic products are recycled, it is highly likely that the additives will be integrated into the new products. Waste plastic, even if it is all of the same polymer type, will contain varying types and amounts of additives. Mixing these together can give a material with inconsistent properties, which can be unappealing to industry. For example, mixing different coloured plastics with different [[Chemistry:Plastic colorant|plastic colorant]]s together can produce a discoloured or brown material and for this reason plastic is usually sorted by both polymer type and color before recycling.<ref name=":0" />

Absence of transparency and reporting across the value chain often results in lack of knowledge concerning the chemical profile of the final products. For example, products containing brominated flame retardants have been incorporated into new plastic products. Flame retardants are a group of chemicals used in electronic and electrical equipment, textiles, furniture and construction materials which should not be present in food packaging or child care products. A recent study found brominated dioxins as unintentional contaminants in toys made from recycled plastic electronic waste that contained brominated flame retardants. Brominated dioxins have been found to exhibit toxicity similar to that of chlorinated dioxins. They can have negative developmental effects and negative effects on the nervous system and interfere with mechanisms of the endocrine system.<ref name=":0" />

=== Health effects ===
Many of the controversies associated with plastics actually relate to their additives, as some compounds can be persistent, bioaccumulating and potentially harmful.<ref name="Ullmann">{{cite journal |last1=Elias |first1=Hans-Georg |last2=Mülhaupt |first2=Rolf |title=Plastics, General Survey, 1. Definition, Molecular Structure and Properties |journal=Ullmann's Encyclopedia of Industrial Chemistry |date=April 14, 2015 |pages=1–70 |doi=10.1002/14356007.a20_543.pub2|isbn=9783527306732 }}</ref><ref name="Transportandrelease">{{cite journal | vauthors = Teuten EL, Saquing JM, Knappe DR, Barlaz MA, Jonsson S, Björn A, Rowland SJ, Thompson RC, Galloway TS, Yamashita R, Ochi D, Watanuki Y, Moore C, Viet PH, Tana TS, Prudente M, Boonyatumanond R, Zakaria MP, Akkhavong K, Ogata Y, Hirai H, Iwasa S, Mizukawa K, Hagino Y, Imamura A, Saha M, Takada H | display-authors = 6 | title = Transport and release of chemicals from plastics to the environment and to wildlife | journal = Philosophical Transactions of the Royal Society of London. Series B, Biological Sciences | volume = 364 | issue = 1526 | pages = 2027–45 | date = July 2009 | pmid = 19528054 | pmc = 2873017 | doi = 10.1098/rstb.2008.0284 }}</ref><ref name="Additive-rev" /> The now banned flame retardants OctaBDE and PentaBDE are an example of this, while the health effects of [[Chemistry:Phthalate|phthalate]]s are an ongoing area of public concern. Additives can also be problematic if waste is burned, especially when burning is uncontrolled or takes place in low- technology incinerators, as is common in many developing countries. Incomplete combustion can cause emissions of hazardous substances such as acid gases and ash which can contain persistent organic pollutants (POPs) such as [[Chemistry:Dioxins and dioxin-like compounds|dioxins]].<ref name=":0" />

A number of additives identified as hazardous to humans and/or the environment are regulated internationally. The [[Chemistry:Stockholm Convention on Persistent Organic Pollutants|Stockholm Convention on Persistent Organic Pollutants]] (POPs) is a global treaty to protect human health and the environment from chemicals that remain intact in the environment for long periods, become widely distributed geographically, accumulate in the fatty tissue of humans and wildlife, and have harmful impacts on human health or on the environment.<ref name=":0" />

Other additives proven to be harmful such as [[Chemistry:Cadmium|cadmium]], [[Chemistry:Chromium|chromium]], [[Chemistry:Lead|lead]] and [[Chemistry:Mercury (element)|mercury]] (regulated under the Minamata Convention on Mercury), which have previously been used in plastic production, are banned in many jurisdictions. However they are still routinely found in some plastic packaging including food packaging. The use of the additive [[Chemistry:Bisphenol A|bisphenol A]] (BPA) in plastic baby bottles is banned in many parts of the world, but is not restricted in some low-income countries.<ref name=":0" />

In 2023, plasticosis, a new disease caused solely by plastics, was discovered in seabirds. The birds identified as having the disease have scarred digestive tracts from ingesting plastic waste.<ref>{{Cite web |url=https://amp.theguardian.com/environment/2023/mar/03/plasticosis-new-disease-caused-by-plastics-discovered-in-seabirds|title=New disease caused by plastics discovered in seabirds |date=March 3, 2023 |work=The Guardian |access-date=March 4, 2023}}</ref>  ”When birds ingest small pieces of plastic, they found, it inflames the digestive tract. Over time, the persistent inflammation causes tissues to become scarred and disfigured, affecting digestion, growth and survival.”<ref>{{Cite web |url=https://www.nhm.ac.uk/press-office/press-releases/new-disease-caused-solely-by-plastics-discovered-in-seabirds-.html|title=New disease caused solely by plastics discovered in seabirds |date=March 3, 2023 |publisher=Natural History Museum |access-date=March 4, 2023}}</ref>

=== Types of additive ===
{| class="wikitable"
! Additive type !! Typical concentration when present (%)<ref name="Additive-rev" /> !! Description !! Example compounds !! Comment !! Share of global additive production (by weight)<ref name=Geyer2017 />
|-
| [[Chemistry:Plasticizer|Plasticizer]]s || 10–70 || Plastics can be brittle, adding some plasticizer makes them more durable, adding lots makes them flexible || [[Chemistry:Phthalate|Phthalate]]s are the dominant class, safer alternatives include  [[Chemistry:Adipic acid#Adipate salts and esters|adipate]] esters ([[Chemistry:Bis(2-ethylhexyl) adipate|DEHA]], [[Chemistry:Dioctyl adipate|DOA]]) and [[Chemistry:Citrate|citrate]] esters ([[Chemistry:Acetyltributylcitrate|ATBC]] and [[Chemistry:Triethyl citrate|TEC]]) || 80–90% of world production is used in PVC, much of the rest is used in [[Chemistry:Cellulose acetate|cellulose acetate]]. For most products loadings are between 10 and 35%, high loadings are used for [[Chemistry:Plastisol|plastisol]]s || 34%
|-
| Flame retardants || 1–30 || Being petrochemicals, most plastics burn readily, flame retardants can prevent this || Brominated flame retardants, [[Chemistry:Chlorinated paraffins|chlorinated paraffins]] || Non-chlorinated [[Chemistry:Organophosphate|organophosphate]]s are ecologically safer, though often less efficient || 13%
|-
| Heat stabilizers || 0.3-5 || Prevents heat related degradation || Traditionally derivatives of lead, cadmium & tin. Safer modern alternatives include barium/zinc mixtures and [[Chemistry:Calcium stearate|calcium stearate]], along with various synergists || Almost exclusively used in PVC. || 5%
|-
| [[Chemistry:Filler (materials)|Fillers]]  || 0–50 || Bulking agents. Can change appearance and mechanical properties, can lower price || [[Chemistry:Calcium carbonate|Calcium carbonate]] "chalk", [[Chemistry:Talc|talc]], glass beads, [[Chemistry:Carbon black|carbon black]]. Also reinforcing fillers like [[Chemistry:Carbon-fiber-reinforced polymers|carbon-fiber]]  || Most [[Physics:Opacity (optics)|opaque]] plastic contains fillers. High levels can also protect against UV rays. || 28%
|-
| Impact modifiers || 10–40 || Improved toughness and resistance to damage<ref>{{cite journal |title=Impact modifiers: how to make your compound tougher |journal=Plastics, Additives and Compounding |date=May 2004 |volume=6 |issue=3 |pages=46–49 |doi=10.1016/S1464-391X(04)00203-X}}</ref> || Typically some other elastomeric polymer, e.g. rubbers, styrene copolymers  || [[Chemistry:Chlorinated polyethylene|Chlorinated polyethylene]] is used for PVC || 5%
|-
| [[Biology:Antioxidant|Antioxidant]]s || 0.05–3 || Protects against degradation during processing || [[Chemistry:Phenols|Phenols]], [[Chemistry:Phosphite ester|phosphite ester]]s, certain thioethers || The most widely used type of additives, all plastics will contain polymer stabilisers of some sort || 6%
|-
| Colorants || 0.001-10 || Imparts colour || Numerous dyes or pigments ||  || 2%
|-
| Lubricants || 0.1-3 || Assist in forming/molding the plastic, includes processing aids (or flow aids), [[Chemistry:Release agent|release agent]]s, slip additives ||  Hazardous PFASs. [[Chemistry:Paraffin wax|Paraffin wax]], [[Chemistry:Wax ester|wax ester]]s, metal stearates (i.e. [[Chemistry:Zinc stearate|zinc stearate]]), long-chain fatty acid amides ([[Chemistry:Oleamide|oleamide]], erucamide) || Very common. All examples form a coating between the plastic and machine parts during production. Reduces pressure and power usage in the extruder. Reduces imperfections. || 2%
|-
| Light stabilizers || 0.05–3 || Protects against UV damage || [[Chemistry:Hindered amine light stabilizers|HALS]], UV blockers and quenchers || Normally only used for items intended for outdoor use || 1%
|-
| Other ||  || Various || Antimicrobials, antistatics, [[Physics:Blowing agent|blowing agent]]s, nucleating agents, clarifying agents ||  || 4%
|}

==Toxicity==
Pure plastics have low toxicity due to their insolubility in water, and because they have a large molecular weight, they are biochemically inert. Plastic products contain a variety of additives, however, some of which can be toxic.<ref name=additives>{{cite journal | vauthors = Hahladakis JN, Velis CA, Weber R, Iacovidou E, Purnell P | title = An overview of chemical additives present in plastics: Migration, release, fate and environmental impact during their use, disposal and recycling | journal = Journal of Hazardous Materials | volume = 344 | pages = 179–199 | date = February 2018 | pmid = 29035713 | doi = 10.1016/j.jhazmat.2017.10.014 | doi-access = free }}{{open access}}</ref> For example, plasticizers like [[Chemistry:Adipic acid#Adipate salts and esters|adipates]] and [[Chemistry:Phthalate|phthalate]]s are often added to brittle plastics like PVC to make them pliable enough for use in food packaging, toys, and many other items. Traces of these compounds can leach out of the product. Owing to concerns over the effects of such [[Earth:Leachate|leachate]]s, the EU has restricted the use of [[Chemistry:Bis(2-ethylhexyl) phthalate|DEHP]] (di-2-ethylhexyl phthalate) and other phthalates in some applications, and the US has limited the use of DEHP, [[Chemistry:Dibutyl phthalate|DPB]], [[Chemistry:Benzyl butyl phthalate|BBP]], [[Chemistry:Diisononyl phthalate|DINP]], [[Chemistry:Diisodecyl phthalate|DIDP]], and DnOP in children's toys and child-care articles through the Consumer Product Safety Improvement Act. Some compounds leaching from polystyrene food containers have been proposed to interfere with hormone functions and are suspected human carcinogens (cancer-causing substances).<ref name="NationalGeographic" /> Other chemicals of potential concern include [[Chemistry:Alkylphenol|alkylphenol]]s.<ref name=Transportandrelease/>

While a finished plastic may be non-toxic, the monomers used in the manufacture of its parent polymers may be toxic. In some cases, small amounts of those chemicals can remain trapped in the product unless suitable processing is employed. For example, the [[Organization:World Health Organization|World Health Organization]]'s [[Organization:International Agency for Research on Cancer|International Agency for Research on Cancer]] (IARC) has recognized [[Chemistry:Vinyl chloride|vinyl chloride]], the precursor to PVC, as a human carcinogen.<ref name="NationalGeographic">{{cite web| vauthors = McRandle PW |title = Plastic Water Bottles|publisher = [[Organization:National Geographic Society|National Geographic]]|date = March–April 2004|url = http://www.thegreenguide.com/doc/101/plastic|access-date = November 13, 2007}}</ref>

===Bisphenol A (BPA)===
Some plastic products degrade to chemicals with [[Biology:Estrogen|estrogen]]ic activity.<ref>{{cite journal | vauthors = Yang CZ, Yaniger SI, Jordan VC, Klein DJ, Bittner GD | title = Most plastic products release estrogenic chemicals: a potential health problem that can be solved | journal = Environmental Health Perspectives | volume = 119 | issue = 7 | pages = 989–96 | date = July 2011 | pmid = 21367689 | pmc = 3222987 | doi = 10.1289/ehp.1003220 }}</ref> The primary building block of polycarbonates, [[Chemistry:Bisphenol A|bisphenol A]] (BPA), is an estrogen-like [[Chemistry:Endocrine disruptor|endocrine disruptor]] that may leach into food.<ref name="NationalGeographic" /> Research in Environmental Health Perspectives finds that BPA leached from the lining of tin cans, [[Medicine:Dental sealant|dental sealant]]s and polycarbonate bottles can increase the body weight of lab animals' offspring.<ref>{{cite journal | vauthors = Rubin BS, Murray MK, Damassa DA, King JC, Soto AM | title = Perinatal exposure to low doses of bisphenol A affects body weight, patterns of estrous cyclicity, and plasma LH levels | journal = Environmental Health Perspectives | volume = 109 | issue = 7 | pages = 675–80 | date = July 2001 | pmid = 11485865 | pmc = 1240370 | doi = 10.2307/3454783 | jstor = 3454783 }}</ref> A more recent animal study suggests that even low-level exposure to BPA results in insulin resistance, which can lead to inflammation and heart disease.<ref>{{cite journal | vauthors = Alonso-Magdalena P, Morimoto S, Ripoll C, Fuentes E, Nadal A | title = The estrogenic effect of bisphenol A disrupts pancreatic beta-cell function in vivo and induces insulin resistance | journal = Environmental Health Perspectives | volume = 114 | issue = 1 | pages = 106–12 | date = January 2006 | pmid = 16393666 | pmc = 1332664 | doi = 10.1289/ehp.8451 | url = http://www.ehponline.org/docs/2005/8451/abstract.html | url-status = dead | archive-url = https://web.archive.org/web/20090119022220/http://www.ehponline.org/docs/2005/8451/abstract.html | archive-date = January 19, 2009 }}</ref> As of January 2010, the ''Los Angeles Times'' reported that the US Food and Drug Administration (FDA) is spending $30&nbsp;million to investigate indications of BPA's link to cancer.<ref>{{Cite news | vauthors = Zajac A |date=January 16, 2010 |title=FDA Issues BPA Guidelines |language=en |work=Los Angeles Times |url=https://www.latimes.com/archives/la-xpm-2010-jan-16-la-na-fda-bpa16-2010jan16-story.html |access-date=July 29, 2021}}</ref> [[Chemistry:Bis(2-ethylhexyl) adipate|Bis(2-ethylhexyl) adipate]], present in plastic wrap based on PVC, is also of concern, as are the volatile organic compounds present in [[Earth:New car smell|new car smell]]. The EU has a permanent ban on the use of phthalates in toys. In 2009, the US government banned certain types of phthalates commonly used in plastic.<ref>{{cite web | vauthors = McCormick LW | url = http://www.consumeraffairs.com/news04/2009/10/pirg_lead_tests.html | title = More Kids' Products Found Containing Unsafe Chemicals | work = ConsumerAffairs.com | date = October 30, 2009 }}</ref>

==Environmental effects==
[[File:More Plastic in the Ocean than Fish Infographic.png|thumb|A communication campaign infographic showing that there will be more plastic in the oceans than fish by 2050]]
Because the chemical structure of most plastics renders them durable, they are resistant to many natural degradation processes. Much of this material may persist for centuries or longer, given the demonstrated persistence of structurally similar natural materials such as [[Earth:Amber|amber]].

There are differing estimates of how much plastic waste has been produced in the last century. By one estimate, one billion tons of plastic waste have been discarded since the 1950s.<ref>{{cite book| vauthors = Weisman A |title=The world without us|date=2007|publisher=Thomas Dunne Books/St. Martin's Press|location=New York|isbn=978-1-4434-0008-4}}</ref> Others estimate a cumulative human production of 8.3 billion tons of plastic, of which 6.3 billion tons is waste, with only 9% getting recycled.<ref>{{cite journal | vauthors = Geyer R, Jambeck JR, Law KL | title = Production, use, and fate of all plastics ever made | journal = Science Advances | volume = 3 | issue = 7 | pages = e1700782 | date = July 2017 | pmid = 28776036 | pmc = 5517107 | doi = 10.1126/sciadv.1700782 | bibcode = 2017SciA....3E0782G }}</ref>

It is estimated that this waste is made up of 81% polymer resin, 13% polymer fibres and 32% additives. In 2018 more than 343 million tonnes of plastic waste were generated, 90% of which was composed of post-consumer plastic waste (industrial, agricultural, commercial and municipal plastic waste). The rest was pre-consumer waste from resin production and manufacturing of plastic products (e.g. materials rejected due to unsuitable colour, hardness, or processing characteristics).<ref name=":0" />

The Ocean Conservancy reported that China, Indonesia, Philippines, Thailand, and Vietnam dump more plastic into the sea than all other countries combined.<ref>{{cite news | vauthors = Leung H |title=Five Asian Countries Dump More Plastic Into Oceans Than Anyone Else Combined: How You Can Help |url=https://www.forbes.com/sites/hannahleung/2018/04/21/five-asian-countries-dump-more-plastic-than-anyone-else-combined-how-you-can-help/#1d663de71234 |access-date=June 23, 2019 |work={{wipe|Forbes}} |date=April 21, 2018 |language=en |quote=China, Indonesia, Philippines, Thailand, and Vietnam are dumping more plastic into oceans than the rest of the world combined, according to a 2017 report by Ocean Conservancy}}</ref> The rivers Yangtze, Indus, Yellow, Hai, Nile, Ganges, Pearl, Amur, Niger, and Mekong "transport 88% to 95% of the global [plastics] load into the sea."<ref>{{cite journal | vauthors = Schmidt C, Krauth T, Wagner S | title = Export of Plastic Debris by Rivers into the Sea | journal = Environmental Science & Technology | volume = 51 | issue = 21 | pages = 12246–12253 | date = November 2017 | pmid = 29019247 | doi = 10.1021/acs.est.7b02368 | bibcode = 2017EnST...5112246S | url = http://oceanrep.geomar.de/43169/4/es7b02368_si_001.pdf | quote = The 10 top-ranked rivers transport 88–95% of the global load into the sea }}</ref><ref>{{cite news | vauthors = Franzen H |title=Almost all plastic in the ocean comes from just 10 rivers |url=https://p.dw.com/p/2oTF6 |access-date=December 18, 2018 |work=Deutsche Welle |date=November 30, 2017 |quote=It turns out that about 90 percent of all the plastic that reaches the world's oceans gets flushed through just 10 rivers: The Yangtze, the Indus, Yellow River, Hai River, the Nile, the Ganges, Pearl River, Amur River, the Niger, and the Mekong (in that order).}}</ref>{{Verify quote|date=February 2021|type=quote punctuation|text=Should the full stop in this quote be placed outside of it instead? See Wikipedia:Manual_of_Style#Punctuation for more information.}}

The presence of plastics, particularly [[Earth:Microplastics|microplastics]], within the food chain is increasing. In the 1960s microplastics were observed in the guts of seabirds, and since then have been found in increasing concentrations.<ref name=Accumulation/> The long-term effects of plastics in the food chain are poorly understood. In 2009 it was estimated that 10% of modern waste was plastic,<ref name=PlasticAge/> although estimates vary according to region.<ref name="Accumulation">{{cite journal | vauthors = Barnes DK, Galgani F, Thompson RC, Barlaz M | title = Accumulation and fragmentation of plastic debris in global environments | journal = Philosophical Transactions of the Royal Society of London. Series B, Biological Sciences | volume = 364 | issue = 1526 | pages = 1985–98 | date = July 2009 | pmid = 19528051 | pmc = 2873009 | doi = 10.1098/rstb.2008.0205 }}</ref> Meanwhile, 50% to 80% of debris in marine areas is plastic.<ref name=Accumulation/> Plastic is often used in agriculture. There is more plastic in the soil than in the oceans. The presence of plastic in the environment hurts ecosystems and human health.<ref>{{cite news |last1=Carrington |first1=Damian |title='Disastrous' plastic use in farming threatens food safety – UN |url=https://www.theguardian.com/environment/2021/dec/07/disastrous-plastic-use-in-farming-threatens-food-safety-un |access-date=December 8, 2021 |agency=The Guardian |date=December 7, 2021}}</ref>

Research on the environmental impacts has typically focused on the disposal phase. However, the production of plastics is also responsible for substantial environmental, health and socioeconomic impacts.<ref>{{Cite journal|last1=Cabernard|first1=Livia|last2=Pfister|first2=Stephan|last3=Oberschelp|first3=Christopher|last4=Hellweg|first4=Stefanie|date=December 2, 2021|title=Growing environmental footprint of plastics driven by coal combustion|journal=Nature Sustainability|volume=5 |issue=2 |language=en|pages=139–148|doi=10.1038/s41893-021-00807-2|bibcode=2021NatSu...5..139C |s2cid=244803448|issn=2398-9629|doi-access=free|hdl=20.500.11850/518642|hdl-access=free}}</ref>

Prior to the Montreal Protocol, [[Earth:Chlorofluorocarbon|CFCs]] had been commonly used in the manufacture of the plastic polystyrene, the production of which had contributed to depletion of the [[Physics:Ozone layer|ozone layer]].

Efforts to minimize environmental impact of plastics may include lowering of plastics production and use, waste- and recycling-policies, and the proactive development and deployment of alternatives to plastics such as for [[Social:Sustainable packaging|sustainable packaging]].

=== Microplastics ===
{{Excerpt|Microplastics}}

===Decomposition of plastics===
{{main|Chemistry:Polymer degradation}}
Plastics  [[Chemistry:Polymer degradation|degrade]] by a variety of processes, the most significant of which is usually [[Physics:Photo-oxidation of polymers|photo-oxidation]]. Their chemical structure determines their fate. Polymers' [[Earth:Plastic degradation by marine bacteria|marine degradation]] takes much longer as a result of the saline environment and cooling effect of the sea, contributing to the persistence of plastic debris in certain environments.<ref name="Accumulation" /> Recent studies have shown, however, that plastics in the ocean decompose faster than had been previously thought, due to exposure to the sun, rain, and other environmental conditions, resulting in the release of toxic chemicals such as [[Chemistry:Bisphenol A|bisphenol A]]. However, due to the increased volume of plastics in the ocean, decomposition has slowed down.<ref name="ScienceDaily">{{cite web |last1= American Chemical Society |title=Plastics In Oceans Decompose, Release Hazardous Chemicals, Surprising New Study Says|url=https://www.sciencedaily.com/releases/2009/08/090819234651.htm|website=Science Daily|access-date=March 15, 2015}}</ref> The Marine Conservancy has predicted the decomposition rates of several plastic products: It is estimated that a foam plastic cup will take 50 years, a plastic beverage holder will take 400 years, a disposable diaper will take 450 years, and fishing line will take 600 years to degrade.<ref name="Plastic Pollution">{{cite web|url=http://plastic-pollution.org/|title=When The Mermaids Cry: The Great Plastic Tide| vauthors = Le Guern C |date=March 2018|website=Coastal Care|archive-url=https://web.archive.org/web/20180405071834/http://plastic-pollution.org/|archive-date=April 5, 2018|url-status=live|access-date=November 10, 2018}}</ref>

Microbial species capable of degrading plastics are known to science, some of which are potentially useful for disposal of certain classes of plastic waste.
*In 1975, a team of Japanese scientists studying ponds containing waste water from a nylon factory discovered a strain of ''[[Biology:Flavobacterium|Flavobacterium]]'' that digests certain byproducts of [[Chemistry:Nylon 6|nylon 6]] manufacture, such as the linear dimer of [[Chemistry:Aminocaproic acid|6-aminohexanoate]].<ref>{{Cite journal | vauthors = Kinoshita S, Kageyama S, Iba K, Yamada Y, Okada H |date=1975 |title=Utilization of a Cyclic Dimer and Linear Oligomers of E-Aminocaproic Acid by Achromobacter Guttatus |journal=Agricultural and Biological Chemistry |volume=39 |issue=6 |pages=1219–1223 |doi=10.1271/bbb1961.39.1219 |doi-access=free}}</ref> Nylon 4 (polybutyrolactam) can be degraded by the ND-10 and ND-11 strands of ''Pseudomonas sp.'' found in sludge, resulting in GABA (γ-aminobutyric acid) as a byproduct.<ref name="pmid19865515" />
*Several species of soil fungi can consume polyurethane,<ref>{{cite journal | vauthors = Russell JR, Huang J, Anand P, Kucera K, Sandoval AG, Dantzler KW, Hickman D, Jee J, Kimovec FM, Koppstein D, Marks DH, Mittermiller PA, Núñez SJ, Santiago M, Townes MA, Vishnevetsky M, Williams NE, Vargas MP, Boulanger LA, Bascom-Slack C, Strobel SA | display-authors = 6 | title = Biodegradation of polyester polyurethane by endophytic fungi | journal = Applied and Environmental Microbiology | volume = 77 | issue = 17 | pages = 6076–84 | date = September 2011 | pmid = 21764951 | pmc = 3165411 | doi = 10.1128/aem.00521-11 | bibcode = 2011ApEnM..77.6076R }}</ref> including two species of the Ecuadorian fungus ''[[Biology:Pestalotiopsis|Pestalotiopsis]]''. They can consume polyurethane both aerobically and anaerobically (such as at the bottom of landfills).<ref>{{cite journal | vauthors = Russell JR, Huang J, Anand P, Kucera K, Sandoval AG, Dantzler KW, Hickman D, Jee J, Kimovec FM, Koppstein D, Marks DH, Mittermiller PA, Núñez SJ, Santiago M, Townes MA, Vishnevetsky M, Williams NE, Vargas MP, Boulanger LA, Bascom-Slack C, Strobel SA | display-authors = 6 | title = Biodegradation of polyester polyurethane by endophytic fungi | journal = Applied and Environmental Microbiology | volume = 77 | issue = 17 | pages = 6076–84 | date = September 2011 | pmid = 21764951 | pmc = 3165411 | doi = 10.1128/AEM.00521-11 | bibcode = 2011ApEnM..77.6076R }}</ref>
*Methanogenic microbial consortia degrade styrene, using it as a carbon source.<ref>{{cite web|url=http://www.ceaa-acee.gc.ca/050/documents/56647/56647E.pdf |title=Deep Geologic Repository Project |website=Ceaa-acee.gc.ca |access-date=April 18, 2017}}</ref> ''[[Biology:Pseudomonas putida|Pseudomonas putida]]'' can convert [[Chemistry:Styrene|styrene]] oil into various biodegradable plastic|biodegradable [[Chemistry:Polyhydroxyalkanoates|polyhydroxyalkanoates]].<ref>{{cite web| vauthors = Roy R |url=http://www.livescience.com/technology/060307_styrofoam_cup.html |title=Immortal Polystyrene Foam Meets its Enemy |website=Livescience.com |date=March 7, 2006 |access-date=April 18, 2017}}</ref><ref>{{cite journal | vauthors = Ward PG, Goff M, Donner M, Kaminsky W, O'Connor KE | title = A two step chemo-biotechnological conversion of polystyrene to a biodegradable thermoplastic | journal = Environmental Science & Technology | volume = 40 | issue = 7 | pages = 2433–7 | date = April 2006 | pmid = 16649270 | doi = 10.1021/es0517668 | bibcode = 2006EnST...40.2433W }}</ref>
*Microbial communities isolated from soil samples mixed with starch have been shown to be capable of degrading polypropylene.<ref>{{cite journal | vauthors = Cacciari I, Quatrini P, Zirletta G, Mincione E, Vinciguerra V, Lupattelli P, Giovannozzi Sermanni G | title = Isotactic polypropylene biodegradation by a microbial community: physicochemical characterization of metabolites produced | journal = Applied and Environmental Microbiology | volume = 59 | issue = 11 | pages = 3695–700 | date = November 1993 | pmid = 8285678 | pmc = 182519 | doi = 10.1128/AEM.59.11.3695-3700.1993 | bibcode = 1993ApEnM..59.3695C | doi-access = free }}</ref>
*The fungus ''[[Biology:Aspergillus fumigatus|Aspergillus fumigatus]]'' effectively degrades plasticized PVC.<ref name="Ishtiaq_2011">{{cite thesis |type=Ph.D. |url=http://prr.hec.gov.pk/Thesis/3362H.pdf |vauthors=Ishtiaq AM |title=Microbial Degradation of Polyvinyl Chloride Plastics |publisher=Quaid-i-Azam University |location=Islamabad |year=2011 |pages= |access-date=December 23, 2013 |archive-date=December 24, 2013 |archive-url=https://web.archive.org/web/20131224083944/http://prr.hec.gov.pk/Thesis/3362H.pdf |url-status=dead }}</ref>{{rp|45–46}} ''Phanerochaete chrysosporium'' has been grown on PVC in a mineral salt agar.<ref name="Ishtiaq_2011" />{{rp|76}} ''P. chrysosporium'', ''[[Biology:Lentinus tigrinus|Lentinus tigrinus]]'', ''[[Biology:Aspergillus niger|A. niger]]'', and ''[[Biology:Aspergillus sydowii|A. sydowii]]'' can also effectively degrade PVC.<ref name="Ishtiaq_2011" />{{rp|122}}
*Phenol-formaldehyde, commonly known as Bakelite, is degraded by the white rot fungus ''P. chrysosporium''.<ref>{{cite journal | vauthors = Gusse AC, Miller PD, Volk TJ | title = White-rot fungi demonstrate first biodegradation of phenolic resin | journal = Environmental Science & Technology | volume = 40 | issue = 13 | pages = 4196–9 | date = July 2006 | pmid = 16856735 | doi = 10.1021/es060408h | bibcode = 2006EnST...40.4196G }}</ref>
*''[[Biology:Acinetobacter|Acinetobacter]]'' has been found to partially degrade low-molecular-weight polyethylene oligomers.<ref name="pmid19865515">{{cite journal | vauthors = Tokiwa Y, Calabia BP, Ugwu CU, Aiba S | title = Biodegradability of plastics | journal = International Journal of Molecular Sciences | volume = 10 | issue = 9 | pages = 3722–42 | date = August 2009 | pmid = 19865515 | pmc = 2769161 | doi = 10.3390/ijms10093722 | doi-access = free | author-link = Yutaka Tokiwa }}</ref> When used in combination, ''[[Biology:Pseudomonas fluorescens|Pseudomonas fluorescens]]'' and ''[[Biology:Sphingomonas|Sphingomonas]]'' can degrade over 40% of the weight of plastic bags in less than three months.<ref>{{cite web|url=http://woohooreport.com/2009/09/wci-student-isolates-microbe-that-lunches-on-plastic-bags/|publisher=The Record.com|title=CanadaWorld – WCI student isolates microbe that lunches on plastic bags|url-status=dead|archive-url=https://web.archive.org/web/20110718081923/http://woohooreport.com/2009/09/wci-student-isolates-microbe-that-lunches-on-plastic-bags/|archive-date=July 18, 2011}}</ref> The thermophilic bacterium ''[[Biology:Brevibacillus borstelensis|Brevibacillus borstelensis]]'' (strain 707) was isolated from a soil sample and found capable of using low-density [[Chemistry:Polyethylene|polyethylene]] as a sole carbon source when incubated at 50&nbsp;°C. Pre-exposure of the plastic to ultraviolet radiation broke chemical bonds and aided biodegradation; the longer the period of UV exposure, the greater the promotion of the degradation.<ref>{{cite journal | vauthors = Hadad D, Geresh S, Sivan A | title = Biodegradation of polyethylene by the thermophilic bacterium Brevibacillus borstelensis | journal = Journal of Applied Microbiology | volume = 98 | issue = 5 | pages = 1093–100 | date = 2005 | pmid = 15836478 | doi = 10.1111/j.1365-2672.2005.02553.x | s2cid = 2977246 | doi-access =  }}</ref>
*Hazardous molds have been found aboard space stations that degrade rubber into a digestible form.<ref>{{cite web|url=https://science.nasa.gov/science-news/science-at-nasa/2007/11may_locad3/| vauthors = Bell TE |year=2007|title=Preventing "Sick" Spaceships }}</ref>
*Several species of yeasts, bacteria, algae and lichens have been found growing on synthetic polymer artifacts in museums and at archaeological sites.<ref>{{cite journal | vauthors = Cappitelli F, Sorlini C | title = Microorganisms attack synthetic polymers in items representing our cultural heritage | journal = Applied and Environmental Microbiology | volume = 74 | issue = 3 | pages = 564–9 | date = February 2008 | pmid = 18065627 | pmc = 2227722 | doi = 10.1128/AEM.01768-07 | bibcode = 2008ApEnM..74..564C }}</ref>
*In the plastic-polluted waters of the Sargasso Sea, bacteria have been found that consume various types of plastic; however, it is unknown to what extent these bacteria effectively clean up poisons rather than simply release them into the marine microbial ecosystem.
*Plastic-eating microbes also have been found in landfills.<ref>{{Cite journal | vauthors = Zaikab GD |date=March 2011 |title=Marine Microbes Digest Plastic |url=http://www.nature.com/news/2011/110328/full/news.2011.191.html |journal=Nature |doi=10.1038/news.2011.191|doi-access=free }}</ref>
*''[[Biology:Nocardia|Nocardia]]'' can degrade PET with an esterase enzyme.<ref>{{Cite journal |last1=Sharon |first1=Chetna |last2=Sharon |first2=Madhuri |date=2012 |title=Studies on Biodegradation of Polyethylene terephthalate: A synthetic polymer |url=https://www.researchgate.net/publication/306202944 |journal=Journal of Microbiology and Biotechnology Research |volume=2 |issue=2 |via=[[Company:ResearchGate|ResearchGate]]}}</ref>
*The fungus ''[[Biology:Geotrichum candidum|Geotrichum candidum]]'', found in Belize, has been found to consume the polycarbonate plastic found in CDs.<ref>{{Cite journal | vauthors = Bosch X |date=2001 |title=Fungus Eats CD |url=http://www.nature.com/news/1998/010628/full/news010628-11.html |journal=Nature |doi=10.1038/news010628-11}}</ref><ref>{{Cite news |date=June 22, 2001 |title=Fungus 'Eats' CDs |work=BBC News |url=http://news.bbc.co.uk/2/hi/science/nature/1402533.stm}}</ref>
*Futuro houses are made of fiberglass-reinforced polyesters, polyester-polyurethane, and PMMA. One such house was found to be harmfully degraded by ''Cyanobacteria'' and ''Archaea''.<ref>{{cite journal | vauthors = Cappitelli F, Principi P, Sorlini C | title = Biodeterioration of modern materials in contemporary collections: can biotechnology help? | journal = Trends in Biotechnology | volume = 24 | issue = 8 | pages = 350–4 | date = August 2006 | pmid = 16782219 | doi = 10.1016/j.tibtech.2006.06.001 }}</ref><ref>{{cite journal | vauthors = Rinaldi A | title = Saving a fragile legacy. Biotechnology and microbiology are increasingly used to preserve and restore the world's cultural heritage | journal = EMBO Reports | volume = 7 | issue = 11 | pages = 1075–9 | date = November 2006 | pmid = 17077862 | pmc = 1679785 | doi = 10.1038/sj.embor.7400844 }}</ref>

[[File:TriagemDeLixo.jpg|thumb|Manual material triage for recycling]]

===Recycling===
{{Excerpt|Plastic recycling}}

==== Pyrolysis ====
By heating to above 500&nbsp;°C in the absence of oxygen ([[Chemistry:Pyrolysis|pyrolysis]]), plastics can be broken down into simpler [[Chemistry:Hydrocarbon|hydrocarbon]]s. These can be reused as starting materials for new plastics.<ref>{{Cite web |last=Tullo |first=Alexander |date=October 10, 2022 |title=Amid controversy, industry goes all in on plastics pyrolysis |url=https://cen.acs.org/environment/recycling/Amid-controversy-industry-goes-plastics-pyrolysis/100/i36 |access-date=January 17, 2023 |website=Chemical & Engineering News}}</ref> They can also be used as fuels.<ref>{{cite web | vauthors = Narayanan S | url = http://www.hindu.com/mp/2005/12/19/stories/2005121900140300.htm | title = The Zadgaonkars turn carry-bags into petrol! | work = The Hindu | date = December 12, 2005 | archive-url = https://web.archive.org/web/20121109220245/http://www.hindu.com/mp/2005/12/19/stories/2005121900140300.htm | access-date = July 1, 2011 | archive-date = November 9, 2012 }}</ref>

=== Climate change ===
According to the OECD, plastic contributed [[Chemistry:Greenhouse gas|greenhouse gas]]es in the equivalent of 1.8 billion tons of [[Chemistry:Carbon dioxide|carbon dioxide]] ({{CO2}}) to the atmosphere in 2019, 3.4% of global emissions.<ref>{{cite web |url=https://www.oecd.org/environment/plastics/increased-plastic-leakage-and-greenhouse-gas-emissions.htm |title=Plastic leakage and greenhouse gas emissions are increasing |publisher=OECD |date= |access-date=August 11, 2022}}</ref> They say that by 2060, plastic could emit 4.3 billion tons of greenhouse gas emissions a year.

The effect of plastics on global warming is mixed. Plastics are generally made from petroleum, thus the production of plastics creates further emissions. However, due to the lightness and durability of plastic versus glass or metal, plastic may lower energy consumption. For example, packaging beverages in PET plastic rather than glass or metal is estimated to save 52% in transportation energy.<ref name=Applications/>

===Production of plastics===
Production of plastics from crude oil requires 7.9 to 13.7 kWh/lb (taking into account the average efficiency of US utility stations of 35%). Producing silicon and semiconductors for modern electronic equipment is even more energy consuming: 29.2 to 29.8 kWh/lb for silicon, and about 381 kWh/lb for semiconductors.<ref>{{cite web | vauthors = De Decker K | veditors = Grosjean V | date = June 2009 |title=The monster footprint of digital technology|url=http://www.lowtechmagazine.com/2009/06/embodied-energy-of-digital-technology.html|access-date=April 18, 2017|publisher=Low-Tech Magazine}}</ref> This is much higher than the energy needed to produce many other materials. For example, to produce iron (from iron ore) requires 2.5-3.2 kWh/lb of energy; glass (from sand, etc.) 2.3–4.4 kWh/lb; steel (from iron) 2.5–6.4 kWh/lb; and paper (from timber) 3.2–6.4 kWh/lb.<ref>{{cite web|date=December 26, 2014|title=How much energy does it take (on average) to produce 1 kilogram of the following materials?|url=http://www.lowtechmagazine.com/what-is-the-embodied-energy-of-materials.html|access-date=April 18, 2017|publisher=Low-Tech Magazine}}</ref>

===Incineration of plastics===
Quickly burning plastics at very high temperatures breaks down many toxic components, such as [[Chemistry:Dioxins and dioxin-like compounds|dioxins]] and [[Chemistry:Furan|furan]]s. This approach is widely used in municipal solid [[Engineering:Incineration|waste incineration]]. Municipal solid waste incinerators also normally treat the [[Physics:Flue gas|flue gas]] to decrease pollutants further, which is needed because uncontrolled incineration of plastic produces [[Biology:Carcinogen|carcinogen]]ic [[Chemistry:Polychlorinated dibenzodioxins|polychlorinated dibenzo-p-dioxins]].<ref>{{cite journal | vauthors = Halden RU | title = Plastics and health risks | journal = Annual Review of Public Health | volume = 31 | pages = 179–94 | date = 2010 | pmid = 20070188 | doi = 10.1146/annurev.publhealth.012809.103714 | doi-access = free }}</ref> Open-air burning of plastic occurs at lower temperatures and normally releases such [[Medicine:Toxicity|toxic]] fumes.

In the European Union, municipal waste incineration is regulated by the Industrial Emissions Directive,<ref>{{Cite journal |last1=Romero |first1=Lina M. |last2=Lyczko |first2=Nathalie |last3=Nzihou |first3=Ange |last4=Antonini |first4=Gérard |last5=Moreau |first5=Eric |last6=Richardeau |first6=Hubert |last7=Coste |first7=Christophe |last8=Madoui |first8=Saïd |last9=Durécu |first9=Sylvain |date=July 2020 |title=New insights on mercury abatement and modeling in a full-scale municipal solid waste incineration flue gas treatment unit |journal=Waste Management |language=en |volume=113 |pages=270–279 |doi=10.1016/j.wasman.2020.06.003|pmid=32559697 |bibcode=2020WaMan.113..270R |s2cid=219948357 |doi-access=free }}</ref> which stipulates a minimum temperature of 850&nbsp;°C for at least two seconds.<ref>{{Cite journal |last1=Janhäll |first1=Sara |last2=Petersson |first2=Mikaela |last3=Davidsson |first3=Kent |last4=Öman |first4=Tommy |last5=Sommertune |first5=Jens |last6=Kåredal |first6=Monica |last7=Messing |first7=Maria E. |last8=Rissler |first8=Jenny |date=October 2021 |title=Release of carbon nanotubes during combustion of polymer nanocomposites in a pilot-scale facility for waste incineration |journal=NanoImpact |language=en |volume=24 |pages=100357 |doi=10.1016/j.impact.2021.100357|pmid=35559816 |s2cid=239252029 |doi-access=free }}</ref>

==History==
The development of plastics has evolved from the use of naturally plastic materials (e.g., [[Chemistry:Natural gum|gums]] and [[Chemistry:Shellac|shellac]]) to the use of the chemical modification of those materials (e.g., natural rubber, [[Chemistry:Cellulose|cellulose]], [[Biology:Collagen|collagen]], and milk proteins), and finally to completely synthetic plastics (e.g., bakelite, epoxy, and PVC). Early plastics were bio-derived materials such as egg and blood proteins, which are organic polymers. In around 1600 BC, Mesoamericans used natural rubber for balls, bands, and figurines.<ref name=Applications>{{cite journal | vauthors = Andrady AL, Neal MA | title = Applications and societal benefits of plastics | journal = Philosophical Transactions of the Royal Society of London. Series B, Biological Sciences | volume = 364 | issue = 1526 | pages = 1977–84 | date = July 2009 | pmid = 19528050 | pmc = 2873019 | doi = 10.1098/rstb.2008.0304 }}</ref> Treated cattle horns were used as windows for lanterns in the [[History:Middle Ages|Middle Ages]]. Materials that mimicked the properties of horns were developed by treating milk proteins with lye. In the nineteenth century, as chemistry developed during the [[History:Industrial Revolution|Industrial Revolution]], many materials were reported. The development of plastics accelerated with [[Biography:Charles Goodyear|Charles Goodyear]]'s 1839 discovery of [[Chemistry:Vulcanization|vulcanization]] to harden natural rubber.

[[File:Alexander Parkes Blue Plaque.jpg|thumb|left|Plaque commemorating Parkes at the Birmingham Science Museum]]
Parkesine, invented by Alexander Parkes in 1855 and patented the following year,<ref>{{cite book|last=UK Patent office|title=Patents for inventions|year=1857|publisher=UK Patent office|page=255|url=https://books.google.com/books?id=0nCoU-2tAx8C&pg=PA255}}</ref> is considered the first man-made plastic. It was manufactured from cellulose (the major component of plant cell walls) treated with [[Chemistry:Nitric acid|nitric acid]] as a solvent. The output of the process (commonly known as cellulose nitrate or pyroxilin) could be dissolved in alcohol and hardened into a transparent and elastic material that could be molded when heated.<ref>{{cite web |url=http://www.websters-online-dictionary.org/ce/celluloid.html |title=Dictionary – Definition of celluloid |publisher=Websters-online-dictionary.org |access-date=October 26, 2011 |url-status=dead |archive-url=https://web.archive.org/web/20091211220823/http://www.websters-online-dictionary.org/ce/celluloid.html |archive-date=December 11, 2009 }}</ref> By incorporating pigments into the product, it could be made to resemble ivory. Parkesine was unveiled at the 1862 International Exhibition in London and garnered for Parkes the bronze medal.<ref>{{cite book| vauthors = Fenichell S |title=Plastic : the making of a synthetic century|date=1996|publisher=HarperBusiness|location=New York|isbn=978-0-88730-732-4|page=[https://archive.org/details/plasticmakingofs00feni/page/17 17]|url-access=registration|url=https://archive.org/details/plasticmakingofs00feni}}</ref>

In 1893, French chemist Auguste Trillat discovered the means to insolubilize casein (milk proteins) by immersion in formaldehyde, producing material marketed as [[Chemistry:Galalith|galalith]].<ref name="ganoksin" /> In 1897, mass-printing press owner Wilhelm Krische of Hanover, Germany, was commissioned to develop an alternative to blackboards.<ref name="ganoksin">{{cite web|url=http://www.ganoksin.com/borisat/nenam/milk-stone.htm|title=Jewelry Stone Make of Milk| vauthors = Trimborn C |publisher=GZ Art+Design|date=August 2004|access-date=May 17, 2010}}</ref> The resultant horn-like plastic made from casein was developed in cooperation with the Austrian chemist (Friedrich) Adolph Spitteler (1846–1940). Although unsuitable for the intended purpose, other uses would be discovered.<ref name="ganoksin" />

The world's first fully synthetic plastic was [[Chemistry:Bakelite|Bakelite]], invented in New York in 1907 by Leo Baekeland,<ref name="Landmark"/> who coined the term ''plastics''.<ref name="Edgar and Edgar 2009" /> Many chemists have contributed to the [[Physics:Materials science|materials science]] of plastics, including Nobel laureate [[Biography:Hermann Staudinger|Hermann Staudinger]], who has been called "the father of [[Chemistry:Polymer chemistry|polymer chemistry]]," and Herman Mark, known as "the father of [[Physics:Polymer physics|polymer physics]]."<ref name="Teegarden 2004" />

After World War I, improvements in chemistry led to an explosion of new forms of plastics, with mass production beginning in the 1940s and 1950s.<ref name=PlasticAge>{{cite journal | vauthors = Thompson RC, Swan SH, Moore CJ, vom Saal FS | title = Our plastic age | journal = Philosophical Transactions of the Royal Society of London. Series B, Biological Sciences | volume = 364 | issue = 1526 | pages = 1973–6 | date = July 2009 | pmid = 19528049 | pmc = 2874019 | doi = 10.1098/rstb.2009.0054 }}</ref> Among the earliest examples in the wave of new polymers were polystyrene (first produced by BASF in the 1930s)<ref name=Applications/> and polyvinyl chloride (first created in 1872 but commercially produced in the late 1920s).<ref name=Applications/> In 1923, Durite Plastics, Inc., was the first manufacturer of phenol-furfural resins.<ref>{{cite web|url=http://www.furan.com/furfural_historical_overview.html|title=Historical Overview and Industrial Development|website=International Furan Chemicals, Inc.|access-date=May 4, 2014}}</ref> In 1933, polyethylene was discovered by Imperial Chemical Industries (ICI) researchers Reginald Gibson and Eric Fawcett.<ref name=Applications/>

The discovery of polyethylene terephthalate is credited to employees of the Calico Printers' Association in the UK in 1941; it was licensed to [[Company:DuPont|DuPont]] for the US and ICI otherwise, and as one of the few plastics appropriate as a replacement for glass in many circumstances, resulting in widespread use for bottles in Europe.<ref name=Applications/> In 1954 polypropylene was discovered by [[Biography:Giulio Natta|Giulio Natta]] and began to be manufactured in 1957.<ref name=Applications/> Also in 1954 expanded polystyrene (used for building insulation, packaging, and cups) was invented by Dow Chemical.<ref name=Applications/>

== Policy ==
Work is currently underway to develop a global treaty on plastic pollution. On March 2, 2022 UN Member States voted at the resumed fifth UN Environment Assembly (UNEA-5.2) to establish an Intergovernmental Negotiating Committee (INC) with the mandate of advancing a legally-binding international agreement on plastics.<ref>{{Cite news |last1=Geddie |first1=John |last2=Brock |first2=Joe |date=March 2, 2022 |title='Biggest green deal since Paris': UN agrees plastic treaty roadmap |language=en |work=Reuters |url=https://www.reuters.com/business/environment/biggest-green-deal-since-paris-un-agrees-plastic-treaty-roadmap-2022-03-02/ |access-date=August 3, 2022}}</ref> The resolution is entitled “End plastic pollution: Towards an international legally binding instrument.” The mandate specifies that the INC must begin its work by the end of 2022 with the goal of "completing a draft global legally binding agreement by the end of 2024."<ref>{{cite web |date=March 2, 2022 |title=Historic day in the campaign to beat plastic pollution: Nations commit to develop a legally binding agreement |url=http://www.unep.org/news-and-stories/press-release/historic-day-campaign-beat-plastic-pollution-nations-commit-develop |access-date=August 3, 2022 |website=UN Environment |language=en}}</ref>

== See also ==
{{colbegin |colwidth=25em}}

* {{Annotated link |American Recyclable Plastic Bag Alliance}}
* {{Annotated link |Corn construction}}
* {{Annotated link |Light activated resin}}
* {{Annotated link |Organic light emitting diode}}
* {{Annotated link |Plastic film}}
* {{Annotated link |Plastic pollution}}
* {{Annotated link |Plastics engineering}}
* {{Annotated link |Plasticulture}}
* {{Annotated link |Plastisphere}}
* {{Annotated link |Refill (scheme)}}
* {{Annotated link |Roll-to-roll processing}}
* {{Annotated link |Self-healing plastic}}
* {{Annotated link |Thermal cleaning}}
* {{Annotated link |Thermoforming}}
* {{Annotated link |Timeline of materials technology}}
'''Plastic in the sense of malleable'''
* {{Annotated link |Plastic arts}}
* {{Annotated link |Plastic ratio}}
{{colend}}

== References ==
{{reflist|colwidth=30em}}
* ''Substantial parts of this text originated from'' [https://web.archive.org/web/20070810225820/http://www.vectorsite.net/ttplast.html An Introduction to Plastics v1.0] ''by Greg Goebel (March 1, 2001), which is in the public domain''.

== Sources ==
{{Free-content attribution
| title = Drowning in Plastics – Marine Litter and Plastic Waste Vital Graphics
| publisher = United Nations Environment Programme
| documentURL = https://www.unep.org/resources/report/drowning-plastics-marine-litter-and-plastic-waste-vital-graphics
| license statement URL = https://commons.wikimedia.org/wiki/File:United_Nations_Environment_Programme_Drowning_in_Plastics_%E2%80%93_Marine_Litter_and_Plastic_Waste_Vital_Graphics.pdf
| license = Cc BY-SA 3.0 IGO
}}

== External links ==
* {{cite web | url = http://americanhistory.si.edu/archives/d8008.htm | title = J. Harry Dubois Collection on the History of Plastics, ca. 1900–1975 | work = Archives Center, National Museum of American History, Smithsonian Institution. | archive-url = https://web.archive.org/web/20060212130150/http://americanhistory.si.edu/archives/d8008.htm | archive-date = February 12, 2006 }}
* {{cite web | url = http://www.plasticsintl.com/sortable_materials.php?display=mechanical | title = Material Properties of Plastics – Mechanical, Thermal & Electrical Properties | work = Plastics International | archive-url = https://web.archive.org/web/20170324052637/http://www.plasticsintl.com/sortable_materials.php?display=mechanical | archive-date = March 24, 2017 }}
* {{cite web | url = http://www.plastiquarian.com/ | title = Plastics Historical Society }}
* {{cite web | url = http://www.plasticsindustry.org/AboutPlastics/content.cfm?ItemNumber=670&navItemNumber=1117 | title = History of plastics, Society of the Plastics Industry | work = plasticsindustry.org | archive-url = https://web.archive.org/web/20090706054409/http://www.plasticsindustry.org/AboutPlastics/content.cfm?ItemNumber=670&navItemNumber=1117 | archive-date = July 6, 2009 }}
* {{cite web | vauthors = Knight L | date = May 17, 2014| url = https://www.bbc.com/news/magazine-27442625 | title = A brief history of plastics, natural and synthetic | work = BBC Magazine }}
* {{cite web | url = http://www.tangram.co.uk/TI-Polymer-Timeline.html | title = Timeline of important milestone of plastic injection moulding and plastics | date = June 27, 2014
| work = Tangram Technology Ltd }}

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[[Category:Plastics| ]]
[[Category:Dielectrics]]

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