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Know what you’re buying

Know what you’re buying

In the wake of the single-use plastic bag ban 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 the materials you’ll commonly see being offered as alternatives to traditional plastic and what to look out for:

Conventional plastic bags:

contain polyethylene (“PE”), typically either high-density polyethylene (HDPE) or low density polyethylene (LDPE). An incredibly useful product that, unfortunately, takes hundreds of years to degrade. Single-use plastic bags have been criticised (and ultimately legislated against) because their useful life is short yet it takes 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 it has never been recycled. It’s predicted that, without significant change, by 2050 there will be more plastic in the ocean by weight than fish.  

Compostable plastic bags:

typically contain a mixture of polymers including 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 (which is limited in NZ) and won’t break down adequately in your backyard compost. Look for home composting certifications like those you’ll see on all ecopack compostable products. Ecopack compostable/biodegradable products are made with GMO-free corn starch and designed to break down in 90 – 180 days (depending on compost environment).

Degradable plastic bags:

conventional plastic with a chemical agent added to speed up the degrading process. Degradable bags, with the help of their TDPA agent, will break down into small particles in sunlight and oxygen in approximately 2 – 4 years (dependent on environment). Please beware that some companies will use the term “biodegradable” when “degradable” would be more appropriate (compostable products may be accurately labelled as biodegradable).

Recycled plastic bags:

made from soft plastic that has been reclaimed 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 than creating virgin plastic. 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. Note whether the recycled product you’re buying has been manufactured from post-consumer plastic content (such as food wrappers, bread bags, courier packs and bubble wrap) or post-consumer waste. And how much recycled content it contains. Please beware that some companies will use the term “recycled” when they’ve simply used their virgin plastic offcuts and by-product, which is a great waste-efficiency measure, but arguably not true recycling. 

Paper bags:

made from the pulp of wood and used for toting groceries long before the rise of single-use plastic bags. Paper bags are now making a come-back. And they are recyclable and biodegradable. 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.