These pastel-toned cabinet handles may look like solid marble, but they are actually made from recycled ocean plastic.

Australian homeware brand Spark & Burnish collaborated with Andrew Simpson of Sydney-based industrial-design studio Vert Design to create the Ocean Plastic Knob, a collection of small handles that can also be used as wall hooks.

The project is helping to raise money for two non-profit organisations working to rid the oceans of plastic waste.

"The premise was simple," explained Priyanka Rao of Spark & Burnish. "So much waste is created by household consumption, why not create an attractive and functional object for the home to remind the occupant to rethink their consumption of plastic packaging?"

"We are lucky in Australia to have such rich diversity of marine life and marine access, and it's our role to carefully consider our impact on it as the health of our reefs and oceans affects the world's ecosystem," she told Dezeen.

The handles are manufactured using plastic collected by ocean conservation organisation Sea Shepard Australia. The funds this organistion raises by selling the ocean plastic goes towards its Marine Debris collection programme, which is working to clean up the Australian coastline.

In addition, a percentage of the proceeds from sales of the Ocean Plastic Knob are donated to the Great Barrier Reef Foundation, to help fund large-scale projects developing solutions to the many threats facing the world's largest coral reef.

"By purchasing even just one item, you can contribute to the work of great not-for-profit organisations working tirelessly to protect our ocean," said Rao.

The handles are made by breaking down the waste plastic into pellets, which are then heated and poured into moulds. They are made to order and, thanks to the nature of the technique, each one has a unique appearance.

There are four colours available: pink, black, grey and green. But the handles can also be ordered in custom colours. They measure 50 millimetres in diameter, with a 35 millimetre projection.

The Ocean Plastic Knob is the latest in a series of new products made using recycled ocean plastic, as people becomes increasingly aware of the environmental impact of virgin plastic.

Other recent products that incorporate ocean plastic include a footwear collection from Spanish fashion brand Ecoalf, which is made using a yarn spun from old plastic bottles, and a Hawaiian shirt by Spanish designer Adolfo Correa.