Good To Know: Biodegradable Bags

As New Providence continues to feel the effects of the recurring fires at the landfill, as well as a general increase in litter throughout the island, columnists Laura Paine and Julia Tomlinson will take turns in hopefully inspiring readers to do their part in reducing the country's waste. This week, Laura takes a look at biodegradable bags.


Are biodegradable bags really biodegradable? Do they really biodegrade away to nothing? Are they the solution to our plastic pollution problem?

Green and appealing biodegradable bags are quickly taking over the white lightweight plastic bags. Stores such as Solomon’s Fresh Market are at the forefront with many other businesses following, including Super Value that has just recently made the switch to biodegradable bags.

The import duty rate for biodegradable bags is now five per cent as opposed to 60 per cent for regular plastic bags, so it makes sense for businesses to become environmentally friendly by switching, which also allows consumer to be more guilt-free when using the stores’ bags. Biodegradable is perceived to be a silver bullet solution: you buy a product and when you throw it away it will disappear. But Is this really the case?

Let’s break it down:

  1. The definition of “biodegradable”

Merriam-Webster defines “biodegradable” as capable of being broken down especially into innocuous products by the action of living things (such as microorganisms). To be truly biodegradable, a material should break down into carbon dioxide (a nutrient for plants), water and naturally occurring minerals that do not cause harm to the ecosystem.

Every resource made by nature eventually biodegrades and returns to nature. Even raw crude oil will degrade when exposed to water, air and the necessary salts. The problem arises when our natural resources are altered by industry in such a way that they are unrecognisable to the natural microorganisms. So, for example, once crude oil is turned into plastic, it will eventually (after approximately one thousand years) degrade into a sludge of toxic chemicals becoming an unsustainable pollution problem.

  1. How long does it take for each material to break down?

Different materials biodegrade at different rates. Any material will ultimately biodegrade, even if it takes centuries. An orange peel takes approximately six months to biodegrade, while a glass bottle will take a million years.

  1. Types of biodegradable bags.

There are two types: bio-based and petrochemical-based.

Bio-based bags are produced from natural origins (for example corn, grains and vegetable oils) and renewable resources and are therefore mostly biodegradable by nature. These plastics are also compostable, breaking down 60 per cent or more, within 180 days or less. Compostable plastic doesn’t just break down: as it decomposes, it will create humus, which adds valuable nutrients to the soil.

Petrochemical-based plastics instead are produced from non-renewable (petrochemical-based) resources. This is the case of Solomon’s Fresh Market and Super Value’s bags, which are made of plastic #2. Most of these bags are manufactured with an additive that results in more rapid fragmentation. Different additives create different conditions for biodegradability such as:

• Thermal plastic requires extremely high temperatures to break down.

• Oxo-biodegradable plastic requires oxygen to break down.

• Hydro-biodegradable plastic requires high humidity to break down.

Many traditional petrochemical-based biodegradable plastics leave behind toxic metals and traces which can contribute to soil and water pollution.

  1. Conditions for biodegradability

Biodegradation of plastics depends on the environment in which they are placed. For a bag to biodegrade, oxygen, light and heat are required, which means that the conditions in a properly managed landfill (such as the one in Freeport) are extremely hostile to the biodegrading process. Nothing is actually meant to decompose there: air, moisture and sunlight – the three factors most necessary to decomposition – are purposely kept out of landfills in order to reduce greenhouse gas emissions. In a dump site like the one in Nassau bags won’t biodegrade either, they just burn from time to time during the dump fires, thus releasing toxins in the air. Lastly, in the oceans bags degrade very slowly as the water reduces UV and oxygen exposure.

Even the bio-based bags won’t decompose easily unless they are discarded in industrial composting systems.

So it would seem that biodegradable bags are not the solution after all unless they are 100 per cent bio-plastic, and even then promoting biodegradable plastics will most likely increase our nation’s plastic consumption as people who currently litter may litter more, and those who brought their own bags to the stores may be less strict about doing so if they believe that the store bags will degrade.

Ultimately, the real solution goes back to our behaviour and the three famous ‘Rs’ (reduce, reuse, and recycle), which are still the most important ways we can protect the health of our planet.

Reducing the amount of plastic we use and throw away whether biodegradable or otherwise is the most impactful choice we can make. Choosing long-lasting products instead of disposable ones helps keep plastic out of our environment. Bringing your own reusable bags to the supermarket will save an average of 30 to 50 plastic bags a week (whether biodegradable or not) from being produced and then released into the environment – approximately 3,000 bags a year. That’s a big difference that requires minimal effort on the part of the consumer.


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