What type of bin liner is best for waste heading to landfill?

Question

I found myself recently needing to purchase something to line my waste/landfill bins with. Up until now, I've been relying on a tub of single-use plastic bags that I've collected over the years, but they've (finally!) run out. When I went to the supermarket, I was quite surprised to find multiple options all claiming to be green or eco friendly. There were:

• 100% virgin plastic (i.e. 'new' bags)
• X% recycled plastic (unknown source)
• X% recycled plastic (sourced from the ocean)
• X% plant-based (unknown source)
• 100% plant-based (made from sugarcane, not compostable)
• Biodegradeable (i.e. compostable, conforming to AS 4736-2006)

The percentages varied between brands: with recycled plastic usually between 80-95% and plant-based between 40-60%.

Which is the right choice for containing things headed for landfill? Or is there a better option?

Notes

• The majority of my household waste usually ends up in either green (garden/food waste) or mixed recycling, but there are a handful of items that still can't go in either of those. We normally fill a small under-sink bin in about a week.
• The waste stream in my local area goes to a managed landfill, where it is buried.
• I have read Alternatives to garbage plastic bags and while I agree that ideally we shouldn't need them at all, or make do on the odd plastic bag that enters the home through other means, unfortunately this doesn't fit everyone's use case, and in the event that garbage bags MUST be purchased, it would be helpful to have these comparisons to make the best (or least-worse) option.

Answer 1

New plastic bags (if you can still find them in your local shops -- I can't anymore) are best for purchasing once and then using maybe 10 times. In contrast to recycled plastic bags that generally break on the first use, new plastic bags stay useful for long because they're very strong. Don't throw such valuable items out with garbage!

Recycled plastic from oceans would be my choice. It's clearly better than recycled plastics from unknown source, because most of recycled plastic is from plastic waste stream that wouldn't go into the oceans if unused. Also once you have used a recycled plastic bag once, it's generally so damaged that you can't use it multiple times after that. Best to throw them to the garbage.

A tip: if the bag you use may contain holes, and you may throw something wet into the garbage can, put four consecutive paper towels bent into "M" as the first thing into the bag. It will capture a minor amount of liquids, meaning the liquids don't stain your garbage can. Of course many wet items should go to biowaste if you create enough biowaste to warrant treating it separately.