Australians spend billions of dollars on beauty products every year, but the leftover packaging mostly ends up in landfill.

It's estimated that more than 10,000 tonnes of cosmetic waste goes to landfill every year in Australia, because make-up products aren't generally accepted in kerbside recycling.

That's because they are too small to be sorted at a regular facility and often contain complex and mixed materials as well as remnant product, which makes them tricky to recycle alongside regular glass and plastics.

So what should you be doing with your old make-up and perfumes?

What are companies doing?

More Australian and international beauty brands and retailers are now offering take-back schemes where you can return used beauty products in-store so they can be recycled.

The products, including skin cream tubes, plastic and metal eyeshadow palettes, foundation and fragrance bottles are sorted into different waste streams like glass, metal, soft and hard plastics.

They are then sent off for processing to be transformed into other products.

What the waste ends up as depends on the company that is doing the recycling and what the packaging was made out of.

Australian recycling company Close the Loop turns plastics into an asphalt additive used in roads.

It said some hard plastics could be shredded and used as a concrete additive, while glass could be crushed and used as a sand replacement for buildings in the construction industry.

Other companies like TerraCycle say their recycled plastic waste can be used in garden beds, outdoor playgrounds and fences.