Know what you’re buying
There has been a huge boom in plastic alternatives and, with it, confusion about which products are genuinely eco-friendly. Here’s a quick run-down on common bag/packaging materials:
Conventional plastic bags:
Plastic bags are made from polyethylene (PE) - typically either high-density polyethylene (HDPE) or low density polyethylene (LDPE). Single-use plastic bags have been criticised (and ultimately legislated against) because their useful life is short yet take considerable resource to produce. Polyethylene is derived from natural gas and petroleum, and after being disposed of the bags hang around for hundreds of years clogging up landfills, polluting waterways or blowing into the bush. Mass production of soft plastic has left us with many billions of tonnes of waste - over 90% of which has never been recycled.
Compostable plastic bags:
Often called bio-plastic, these bags contain PBAT, PLA and a plant-based polymer (such as corn-starch or sugarcane). Compostable materials are designed to degrade in moist conditions and return to carbon dioxide and water without leaving harmful residues in the process. Please note that all compostable products are not equal – some are only suitable for industrial/commercial composting and won’t break down adequately in your backyard compost. Look for home composting certifications to ensure you’re getting the real deal.
Degradable plastic bags:
These are made from conventional plastic with a chemical agent added to speed up the degrading process. Degradable plastics have been legislated out in many states. They break down into small particles in sunlight and oxygen in approximately 2 – 4 years (dependent on environment) but have been attributed to microplastics.
Recycled plastic bags:
How ‘sustainable’ a recycled product is depends on where the raw material has comes from. Some “recycled” products simply have a little post-consumer plastic added (Ie. virgin plastic offcuts or by-product, which is a great waste-efficiency measure, but arguably not true recycling). When WE talk about recycling we mean post-consumer trash that’s been collected and given a second life. When plastics are reused, and made into new products, the production does not require additional fossil fuels for raw material, making it much less intensive on the environment. Recycled plastic production is improving quickly and it’s now possible to produce recycled products with comparable strength and performance as their virgin plastic counterparts. And they’re able to be recycled over again.
Ocean plastic bags:
Like regular recycled bags, these are made with raw material that’s been collected and recycled. What’s different about it is that the post-consumer trash has been collected comes from shorelines, waterways and coastal communities. This is referred to as ocean bound plastic (OBP). It’s important to collect OBP, before it washes out to sea, because we now know that 80% of plastic in the ocean comes from land.
Humble and traditional, paper bags are made from the pulp of wood and were used for toting groceries long before the rise of single-use plastic bags. Paper bags have made a come-back because they’re recyclable and biodegradable. But they also use a massive amount of water to produce. Where possible, buy kraft paper bags that have been made from recycled paper and sourced from sustainable forests; look for the Forest Stewardship Council (FSC) mark.