Written by Deepak Pant
From the time the first synthetic polymer was invented in the 1800s for substituting ivory, to the early 1900s when Leo Baekeland invented Bakelite for substituting shellac, until the present day when plastics have replaced almost all traditional materials, they have become a part of our lives. However, while we continue to depend on plastics for different tasks, our understanding of this material remains low.
Although there are concerns regarding the hazards of the use of plastics on human health and environment, it is imperative to understand that plastic itself is not harmful. It is our irresponsible behaviour of littering and poor attention to safe disposal of waste generated in cities that is the elephant in the room. This brings to the fore, the importance of knowing different types of plastics and their use for various functions. For example, PVC is used for making cables and pipes; polyethylene terephthalate (PET) is used for bottles, jars, clamshells and trays; high-density polyethylene (HDPE) is used for making bottles and carboys; low density polyethylene (LDPE) is used for making milk bags, cling films, etc.; polypropylene (PP) is used in microwave containers and sheets; and polystyrene (PS) is used for making test tubes, thermocol etc. For domestic use, PET packaging is preferred for containers, water bottles, bottles for packaging dishwashing liquid, liquid hand soap, mouthwash, household cleaners. It is also the most preferred material for medicinal and pharma packaging as it does not interfere with the drug or its properties.
Polyethylene terephthalate (PET) also addresses the many gaps in other forms of packaging such as brick cartons. Brick cartons are multi layered, multi-material packaging, popularly called tetra packs. They are used to pack long-life milk, juice and various other liquids. These containers help in retaining the shelf life of products by protecting them from being contaminated by ingress of air and other contaminants. It is made of three materials which are layered. The outer layer is paper (made from wood) which constitutes 75 per cent of the product, the middle layer or 5 per cent of the container is aluminium and the innermost layer, which comes in direct contact with the food item, is plastic.
This multi-material composition makes it difficult to recycle these cartons. The opaque packaging of the boxes makes it difficult for consumers to gauge the quality of liquid from outside, resulting in purchase of a product that can be hazardous to consumer health safety, at times.
On the other hand, PET is high-quality plastic and the containers are made from just a single polymer, hence, it can be recycled eminently. PET bottles, which are being used predominantly today, are highly recyclable with a recycling rate of 90 per cent in India, one of the best in the world.
PET is an energy-efficient packaging material and even when its raw materials are derived from natural gas or crude oil, it has a favourable sustainability profile compared to paper, aluminium, glass and other materials. It is a strong, clear, transparent and lightweight plastic that is used globally for packaging foods and beverages, especially soft drinks, juices and water. It has an efficient gas barrier performance against carbon dioxide and oxygen. Therefore, PET is considered as the best polymer for water bottles and beverage bottles.
Recently, the National Green Tribunal (NGT) declared that the use of PET bottles for packaging of pharmaceuticals is safe. An expert committee led by former Secretary of the Department of Biotechnology, the late MK Bhan, set up by the Health Ministry in 2015, submitted a report to the NGT stating that there is no substantial evidence to prove that the use of PET can leach substances beyond limits that pose threat to human safety.
The NGT then appointed an Expert Committee of CPCB, BIS, DGHS and FSSAI (The Food Safety and Standards Authority of India) as the nodal agency to finalise the regulations to address the packaging issues in a more comprehensive manner. The FSSAI has now framed draft regulations. The expert committee suggested that transparency requirements be prescribed in FSSAI’s packaging regulations. It has also decided that the appropriate amendments be published by the Bureau of Indian Standards (BIS) in harmony with their national regulations as soon as a notification to this effect was issued by FSSAI.
The committee further decided to recommend that the alternative food grade packaging materials such as paper-based multi-layer packaging and metal cans suitable for drinking water may be considered for incorporation.
The pandemic has reaffirmed the importance of PET. The packaging is being used in several products such as blood collection tubes, bottles for sanitisers, Ayurvedic preparations, water food containers, among others. Its light weight makes it a more feasible packaging product for take away foods.
As most people struggle to understand the environmental footprint plastics leave, many turn to brick cartons for a more sustainable alternative. The big question is— can brick cartons replace plastics as a sustainable packaging material?
As per a report by the National Chemical Laboratory, about 70 per cent of PET bottles get recycled into polyester fibres in India while an estimated 15 per cent get converted into straps and films. The PET recycling business in the country stands at Rs 3,500 crore annually. Interestingly, the Indian cricket team’s apparel for the 2015 world cup was made from recycled PET bottles and their current jersey is made from the same material. In view of these studies, it should be possible to educate people about the benefits of PET and the reasons it is one of the world’s most widely used and trusted type of plastic
In any case, the government and the food packing industry need to work in tandem to create sustainable waste management models for packaging materials. One such strategy is the extended producer responsibility (EPR), an environmental protection initiative that aims at decreasing total environmental impact from a product and its packaging. This is done by ensuring producers take complete onus for the entire lifecycle of their products including recycling, final disposal and packaging. We need to introduce cost-effective and scalable waste management systems to recycle plastic, as well as other waste. There should be strict laws to combat the crux of the problem — the irresponsible behaviour of littering. India should adopt executable waste management processes like incentivised recycling. The policy is already implemented by several countries like the US, UK, and Singapore.
The writer is Professor of Chemistry, Dean and Head, School of Chemical Sciences, Central University of Haryana