There is no such thing as an eco-friendly landfill, since most landfill sites are essentially very large plastic containers. But if you're trying not to put contaminants or plastic items into landfill, it makes no sense to line your bin with a plastic bag.
Maistic are one of my favourite brands (along with Loofco); they have some very sensible, easy swap items for Plastic Free July, and their compostable bin bags are a good example. They look and behave like normal bin liners but are made from 'bioplastic', which contains material from plant by-products and food waste (which is pretty cool).
Maistic compostable bin bags will break down in a few years, compared to the hundreds of years that regular bin bags will hang around. They have that smooth, soft feel of food waste caddy liners, but they are a fair bit bigger (although not as big as a regular black refuse sack).
If you buy any compostable or biodegradable bags, note two important things:
- Some items have a 'best before date' -- either an implied one, or a specific one printed on the box. Most degradable bags start to break down after about a year, although they can remain intact for longer, depending on where and how they are stored. Providing you've stored your degradable bin bags in a cool, dark place, they should survive past the best before date, but it's a good idea just to check them for weak spots if they've been in warm or wet storage.
- Items that are labelled 'compostable' should meet certain standards, like EN13432 (these bin bags do). If bags look like plastic and are labelled 'biodegradable' but not compostable, or they aren't tested to these standards, it's best not to put them in a compost bin -- just because you can't be absolutely sure that they'll break down in a short enough time to use the compost.