How do we replace plastic?
In a very short period of time, plastic has earned popularity in various aspects of packaging and other many engineering applications.
The utility of single-use plastic (SUP) in packaging has emerged due to its excellent preservation capabilities, protection abilities and low prices. It is a unique solution for the application in packaging food items to maintain the freshness of the food items.
However, it has drawbacks.
The plastic like PVC, PS, Celluloid were discovered in the nineteenth century and later on PE, PP were commercialized. From the beginning of the twentieth century, it readily replaced the other packaging materials made of glass or paper due to its synthetic nature, high production rate, excellent barrier properties, high mechanical durability and versatility.
Low density polyethylene (dispensing bottles, wash bottles, tubing, etc.), linear low density polyethylene (plastic wrap, stretch wrap, pouches, toys, covers, lids, pipes, buckets and containers, etc.), polypropylene (Plastic containers, Reusable water bottles, Medical components, Outdoor furniture, Toys, Luggage, Car parts, etc.), cellophene, polyvinyl chloride (window frames, drainage pipe, water service pipe, medical devices, blood storage bags, cable and wire insulation, resilient flooring, roofing membranes, stationary, etc.), are few examples of SUP which are completely non-biodegradable and remains as it is in the nature for more than 450 years [1]. Then it is disposed directly to the nature by the most of its users.
SUP is defined as the product whose life cycle is less than few hours, non-biodegradable under domestic composting or landfill conditions, non-retrievable and which loses more than 95% of its economic value after single use.
Huge amount of plastic waste is generated due to our ‘‘throw away culture’’ [2]. Most of the plastic waste goes to either landfill or various water bodies like ocean, river, lake, pond etc. According to the prediction of Dr. Lebreton [3], ‘‘at least 79 (45–129) thousand tonnes of ocean plastic are floating inside an area of 1.6 million km2 ’’. This directly affects marine life as well as raises the pollution in nature. Dr. Nelsen, stated that ‘‘An estimated 8.3 billion tons of virgin plastics have been produced to date, of which 4.9 billion tons have ended up in landfills or natural environment’’ [4].
In Europe, ‘‘25 million tonnes of postconsumer plastic waste is generated every year’’ [5]. In order to find effective remedy to mitigate the ever increasing pollution anti-single-use plastic movement has been initiated all over the world.
According to Dr. Maguire [2], 2018 is the year which is marked as turning point in the history of ‘‘plastic pollution’’. In this year, U.S.A., The European Commission, The UK, Chile, banned the use of SUP products.
With the immediate effect, supermarkets and many companies phased out lightweight plastic bags. Many transnational companies have restricted plastic straws and replaced it with paper based straws. But the fact is SUP has become an important part of our life today and it is very difficult to find a suitable replacement for it.
Rather than replacing it, a solution or strategy or a roadmap to mitigate the hazards of plastic waste is required to control the pollution generated from plastic waste. Biopolymers, bio-based polymers, edible polymers are under focus in recent days but its many drawbacks limits its usage.
Prime limitations include:
high process cost,
low production rate,
brittle characteristics and
inferior barrier characteristics.
Recycling is another thought to control the plastic pollution through converting the waste into meaningful products which are also drawing attention of the researchers as an effective solution to the plastic waste. Consequences of the ban imposed by government bring about development of several products by simply mixing the non-biodegradable plastics with biodegradable plastics by industries.
Mixing or blending processes limits its recyclability and exhibits partial degradation. Even after degradation, the non-biodegradable part is fragmented into microplastics which have notable ecological impact [5].
It has come to light that micro plastics present in oceans are also being consumed by marine organisms such as fishes and shellfish species which disturbs the marine life extensively. Hence, finding right strategy to mitigate the plastic waste related issues has becoming inevitable today.
It can be proposed that replacing nonrecyclable SUP and controlling the misuse of single-use packaging materials are able to bring positive changes in this context. In spite of many attempts to create a replacement of SUP in the last decade, it still remains a problem.
The development of biopolymer-based edible packaging system is one of such alternative to SUPs.
Biopolymers may help in the reduction of dependence on conventional plastic made from petrochemicals, minimizing the global pollution caused by the use of non-biodegradable SUPs, thus helping in moving towards a green economy. But the myth of bio-degradation of such materials in nature poses a great challenge in dealing with the pollution by plastic waste.
Edible materials on the other hand come with a great potential to be used as packaging materials. The use of many biopolymers is highly efficient in reducing global plastic debris because of its biodegradability, palatability and environmental friendliness. At the same time, partially biodegradable polymers are equally dangerous as it forms microplastics which indirectly affect human health due to its deposition in various organs. Hence, it may be beneficial to use plastics that are either 100% recyclable or completely edible.
Biopolymers can be one of the best alternative for developing packaging materials, cup, water bottles, spoons, and edible circuits etc. but has their own limitations.
However, at the moment, the best way to reduce plastic waste is to reduce the use of plastic items in the first place.
As consumers, we have the power to change the market by making sustainable choices every day. Do not buy food wrapped in plastic, buy from environmentally friendly companies, use reusable cups and bottles, and so forth.
Little changes can make the real difference!
References
[1] Hahladakis JN (2020) Delineating the global plastic marine litter challenge: clarifying the misconceptions. Environmental Monitoring and Assessment 192(5)
[2] Maguire R, Johnson H, Taboada MB, Barner L, Caldwell GA (2019). A review of single-use plastic waste policy in 2018: What will 2019 hold in store?, Faculty of Law Blog, Queensland University of Technology, https://eprints.qut.edu.au/127711/. Accessed 16 April 2020.
[3] Lebreton L, Slat B, Ferrari F, Sainte-Rose B, Aitken J, Marthouse R, Hajbane S, Cunsolo S, Schwarz A, Levivier A, Noble K (2018) Evidence that the great Pacific garbage patch is rapidly accumulating plastic. Sci Rep 8(1):1–15
[4] Nelsen TD, Hasselbalch J, Holmberg K, Stripple J (2020) Politics and the plastic crisis: a review throughout the plastic life cycle. Energy and Environment, Wiley Interdisciplinary Reviews. https://doi.org/10.1002/wene.360
[5] Dey A, Dhumal CV, Sengupta P, Kumar A, Pramanik NK, Alam T. Challenges and possible solutions to mitigate the problems of single-use plastics used for packaging food items: a review. Journal of Food Science and Technology. 2021 Sep;58(9):3251-69.