a pair of flip flops on the beach

Known as “plakkies” in South Africa, “slippers” in Hawaii, and “thongs” in Australia, the flip-flop is universally cherished around the world. The flip-flop is the oldest form of footwear we know of, dating back to Ancient Egypt around 4,000 B.C. Nowadays, the flip-flop is the world’s most popular shoe by a landslide, with over 3 billion pairs sold per year around the globe. 

Flipping the Script on Flip-Flops

Shoes are a major pollutant in our oceans and landfills. The best thing you can do with the shoes that you no longer want is to give them a new pair of feet to call home. Donate your old and worn out shoes to your closest non-profit store or shelter. Goodwill is a popular choice with locations across the nation. Another great option is to recycle your old pairs. Soles 4 Souls accepts used shoes and redistributes them to those in need globally. You can even mail them your old shoes free of charge. 

Algenesis Materials, a technology and material science company, is collaborating with major shoe manufacturers and expects to have their biodegradable algae flip-flops, along with other algae-based products, on the market by January 2021. Currently, other options include the fair-trade, natural rubber “Ollieworlds,” the 100% recycled wine cork “Soles,” and many more. There are so many great flip-flop options.

corals under water

A Solution for Clean Oceans

Unfortunately, being the most popular shoe means that the flip-flop is also one of the most widespread pollutants. Flip-flops are responsible for an enormous amount of plastic waste, which threatens marine wildlife and the ocean’s overall health. It is estimated that by 2050, plastic pollution in the ocean will outweigh the total amount of fish, and 90% of our coral reefs will be dead. 

But there is hope! The Earth’s oceans are resilient and by taking action, we can help prevent further damage to our oceans. Dr. Stephen Mayfield, a biology professor at U.C. San Diego, stated that flip-flops account for almost 25% of plastic pollution in the ocean. In an effort to combat the troubling effects of flip-flop pollution, Mayfield and a team of researchers have been working on an eco-friendly alternative.

Microplastics Create A Macro-Problem

Shoes today are made of traditional polyurethane. Traditional polyurethane is difficult to recycle, contains cancer-causing materials, and is not biodegradable. The polyurethane in flip-flops can last over 500 years in the environment. “The life of material should be proportional to the life of the product,” Mayfield says. 

Flip-flops made of traditional polyurethane that end up in the water break down into microplastics. The U.S. National Oceanic and Atmospheric Administration defines microplastics as any plastic that is less than 5 mm in length. When a flip-flop made of traditional polyurethane wears down into microplastics, they can easily end up in the ocean through our waterways, even those with filtration systems.

rocks with algae

Reinventing The Shoe

In collaboration with Algenesis Materials, Mayfield’s team developed biodegradable flip-flops using algae-based polyurethane materials. Growing their own algae in shallow ponds, Mayfield’s team eventually found a formulation of algae oil combined with synthetic material that met required standards for soles of shoes and flip-flops. 

Their goal is to eventually use exclusively organic materials in their shoes. “After hundreds of formulations, we finally achieved one that met commercial specifications,” Mayfield said, “These foams are 52 percent bio-content – eventually we’ll get to 100 percent.”

They hope to achieve a material that is 100% renewable within five to six years. His team found that the new flip-flops can biodegrade and fully decompose in under 18 weeks. The material is not exclusive to flip-flops, and can be used as a polyurethane alternative in a number of practices, opening up the gates to algae based materials in numerous industries and products.

What will be the fate of your future footwear? When in the market for a new pair of flip-flops, consider ones that are eco-friendly and made of natural or recycled materials. Always try to repair the ones you have before purchasing a new pair. If that’s not possible, there are many eco-friendly options to choose from.