Compostable vs degradable bags: What’s the difference?

If you’ve ever stood in the supermarket or scrolled online wondering whether to choose compostable vs degradable bags, biodegradable, oxo-degradable, or plant-based bags… you’re not alone. The packaging world is full of confusing terms, and unfortunately, some of them are more about greenwashing than being genuinely green.

At Ecopack, we want to keep things simple and clear. So, let’s unpack the differences; we’ll also explain why microplastics are such a problem, and how to spot the real deal when you’re shopping for eco-friendly bags.

Compostable vs degradable bags: What’s the difference?

Compostable bags (like our compostable bin liners and resealable snaplock food bags) break down completely in a compost environment. Microbes turn them into carbon dioxide, water, and biomass. They leave behind nothing nasty — and definitely no microplastics.

Degradable or oxo-degradable bags, on the other hand, use regular plastic mixed with a chemical additive. That additive makes the bag break apart faster when it’s exposed to sunlight, heat, or oxygen. It sounds fine at first, but instead of disappearing, they crumble into tiny plastic fragments. Those fragments become microplastics and remain in soil, waterways, and even food chains for decades.

When comparing compostable vs degradable bags, the compostable option wins every time. It’s safer for people and for the planet.

Why microplastics matter in the compostable vs degradable bags debate

Microplastics are now found almost everywhere — in rivers, oceans, the air, and even in our bodies. They’re so small that marine life often mistakes them for food. Once they enter the food chain, they stay there.

Scientists have found microplastics in more than 1,300 animal species. One recent study even detected them in human carotid artery plaque. This widespread contamination threatens human health, marine life, and the environment.

That’s why compostables are such a game-changer. When you use a certified compostable bin liner in your kitchen caddy, or one of our compostable ziplock bags for snacks and leftovers, you can be sure it won’t leave behind a trail of plastic crumbs. Instead, it breaks down naturally, just like food scraps.

Plant-based bags vs compostable options: what’s the difference?

You might also come across plant-based bags—these are made using renewable plant inputs (like sugarcane) instead of fossil fuels. That’s a positive step because it usually means a lower carbon footprint in production.

But here’s the catch: plant-based doesn’t mean compostable. Unless the bag carries proper compostable certification (like AS 4736 or AS 5810), it will behave just like a regular plastic bag at the end of its life.

So, while plant-based plastics can claim reduced CO₂ emissions in manufacturing, they won’t break down safely in compost unless they’re tested and certified. The only green tick you can truly give them is for the renewable inputs—not for end-of-life outcomes.

Certifications: The gold standard

Not all bags labelled “eco” are created equal. The most important thing to look for is both home and commercial composting certification.

For Australian customers, that means checking for:

• The Australasian Bioplastics Association’s seedling logo and AS 4736 (commercially compostable)
• The Australasian Bioplastics Association’s biodegradable logo AS 5810 (home compostable)

These standards guarantee that the bag really will break down in a compost system, and won’t leave toxic residue or microplastic pollution behind. At Ecopack, our compostable bin liners, compostasble postage bags, and compostable food packaging products are all home and commercially compostable certified…so you can go ahead and compost them with confidence.

Everyday compostable options

We know that making sustainable swaps can feel overwhelming, so we keep our product range practical and easy to use:

• Compostable Bin Liners – From small kitchen caddy bags right up to big 240L wheelie bin liners, all made from GMO-free corn starch and printed with non-toxic water based inks. Perfect for keeping food scraps, organics and green waste contained before they head to compost.
• Compostable Ziplock Bags – Just like the resealable snaplock bags you know and love, but made to safely break down after use. Ideal for snacks, lunches, storing leftovers, portioning, freezing fruit, or even organising stationery and craft items.

Both product ranges are a simple, everyday way to cut down on single-use plastics without sacrificing convenience.

The bottom line

If you want to make a genuine difference, steer clear of degradable or oxo-degradable plastics. They may sound green, but they just add to the microplastics problem. And don’t be fooled into thinking all plant-based plastics are compostable.

Instead, choose certified compostable products—that are designed to safely return to nature. Little swaps really do add up, and when we all pitch in, the planet wins.