Plastic Bag Alternatives: Bio-degradable, Compostable or Reusable?

Author: Zero Waste Volunteers

Let's look at all the facts that discuss the environmental impacts of plastic bags and the various alternatives at our disposal so you can make an informed decision regarding your pick.

Plastic Bags:
Propylene plastic bags are made from limited fossils fuels and their manufacturing releases contaminant by-products into the atmosphere and the end product does not biodegrade for hundreds of years.

We currently use 500 billion bags every year worldwide. It takes twelve million tons of petroleum to meet the production of plastic bags for the country each year. Polyethylene, polyvinyl chloride, and polystyrene are the composition base in the manufacture of plastics, these synthetic polymers have high chemical resistance because of which they are non- biodegradable. It also requires a significant amount of money and resources to clean up and dispose of these plastic bags like clean up and landfill costs for plastic bags each year. Polypropylene bags require only 14 uses before they become more eco-friendly than plastic bags. They get buried in landfills may take up to 1,000 years to break down, and in the process, they photo-degrade, becoming microplastics that absorb toxins and continue to pollute the environment. Moreover, in landfills, or elsewhere, plastics survive the harshest conditions, such as floating around in a marine environment under blistering, unrelenting sunshine or frozen into arctic ice for years before finally floating away and landing on some faraway shore. The production of plastic bags consume millions of gallons of oil that could be used for fuel and heating. The problem is worsening as the average human in India uses 3 kg of plastic per person per year. Build ups of huge quantities of plastic bags are well known to block local drainage systems and they also pose health risks to human populations as they leach toxins into water supplies. It takes 500 (or more) years for a plastic bag to degrade in a landfill.

Only 1 percent of plastic bags are returned for recycling. That means that the average family only recycles 15 bags a year; the rest end up in landfills or as litter. The situation worsens as many plastic bags that are collected by recycling companies cannot really be recycled. Most of these bags actually end up in landfills and sit there for hundreds of years.

It comes at a huge cost to our biodiversity as at least 267 different species have been affected by plastic pollution in the ocean and around 100,000 marine animals are killed by plastic bags annually. One in three leatherback sea turtles have been found with plastic in their stomachs.

Bio-degradable Bags:
Biodegradable plastic is plastic that’s designed to break up when exposed to the presence of microorganisms, it is usually made from natural byproducts, and follows rigorously controlled conditions of temperature and humidity in industrial environments. Most biodegradable and compostable plastics are called bioplastic and they are generally made from plants (such as bamboo or sugarcane) rather than fossil fuels. To fully break down, biodegradable plastics require the right environment, which usually means commercial processing. If biodegradable plastic is left to break down in a natural environment – such as in landfills or the sea – it often only breaks down into micro-plastics. These micro-plastics can create ‘plastic smog’ in parts of the ocean and accumulate in soils.

Compostable Bags:
Instead of using plastic made from petrochemicals and fossil fuels, compostable plastics are derived from renewable materials like corn, potato, and tapioca starches, cellulose, soy protein, and lactic acid. Compostable plastics are non-toxic and decompose back into carbon dioxide, water, and biomass when composted.

Don’t get confused- compostable plastics are not the same as biodegradable or bio-based conventional plastics. Some of the first alternative plastics were hybrid plastics made of both petroleum-based and plant-based resins. These hybrid plastics were not truly compostable because they contained petroleum.

In theory, bags labelled as 'compostable' are made from vegetable matter like potato or corn starch which fully break down. However, the conditions have to be right for them to break down and often it isn't hot enough in a home compost situation. It might need centralised composting facilities where the compost is guaranteed to reach high temperatures.

Some retailers are heralding the use of compostable packaging as a solution to landfill problems. However, sceptics argue that most compostable packaging will be put in the normal waste for disposal in a landfill, with the result that, as with any other organic matter in a landfill, as it degrades it will give off methane.

A key worry about the use of compostable packaging is that it promotes recycling, rather than reducing the amount of waste produced in the first place. It is always better to reduce and reuse than to recycle.