How Floral Foam Harms the Earth—and What to Use Instead

Those familiar green blocks aren't exactly earth-friendly.

You've probably seen those green blocks known as floral foam or Oasis in flower arrangements before, and maybe even used it yourself to hold your blooms in place. Though floral foam has been around for decades, recent scientific studies have found that the product can be harmful to the environment. Specifically, it breaks down into microplastics that can contaminate water supplies and hurt aquatic life. Plus, the foam's dust may cause respiratory issues for people. For these reasons, major floral events such as the Royal Horticultural Society's Chelsea Flower Show and the Slow Flowers Summit have sworn off floral foam. Instead, florists are increasingly leaning into floral foam substitutes to design their pieces. Here's why you should too, and what you can use instead to arrange your flowers.

florist using floral foam to create floral arrangement
Africa Studio / Adobe Stock

What is floral foam?

Floral foam is a light-weight, water-absorbent material that can be placed in the bottom of vases and other vessels to create a foundation for floral designs. According to Rita Feldmann, founder of the Sustainability Floristry Network based in Australia, "both florists and consumers have long believed the green, crumbly foam to be a natural product." But in fact, floral foam is a type of plastic.

The green foam product wasn't originally invented for flower arranging, but in the 1950s, Vernon Smithers of Smithers-Oasis patented it for this use. Feldmann says Oasis floral foam quickly gained popularity with professional florists because it's "very cheap and it is very easy to use. You simply cut it, soak in water, and poke the stems in." The product is especially useful for arranging flowers in vessels that would be hard to handle without a sturdy base to place the blooms inside. "Its invention made floral design very accessible to inexperienced arrangers who couldn't get the stems to stay where they wanted them to," she adds.

green floral foam blocks on white background
Hopkins Studio

Is floral foam safe?

Although floral foam is made from ingredients that are known carcinogens, such as formaldehyde, only trace amounts of these toxic chemicals remain in the finished product. The biggest concern with floral foam is what happens when it's disposed of. The foam isn't recyclable, and while it's technically biodegradable, it actually breaks down into tiny particles called microplastics that can remain in the environment for hundreds of years. Scientists are becoming increasingly concerned with the health risks posed by microplastics in the air and water, both to humans and other creatures.

For example, a study published by the RMIT University in Science of the Total Environment in 2019 is the first to show that microplastics from floral foam is impacting aquatic creatures. The researchers found that the microplastics both physically and chemically harmed a range of freshwater and marine species that swallowed the particles.

Another recent study, by researchers with the Hull York Medical School, is the first to discover microplastics in human lungs. The results indicate that breathing in microplastics is a significant source of exposure. Along with floral foam, airborne microplastics come from products such as bottles, packaging, clothing, and cosmetics. However, exactly how these microplastics may affect humans and other animals isn't yet known.

Until further research can hopefully provide more insight into the dangers of microplastics from floral foam and other sources, florists like Tobey Nelson of Tobey Nelson Events + Design, LLC., are concerned about inhaling dust released when working with the product. Although Oasis recommends that florists use masks while handling their product, many don't. "I just hope that in 10 or 15 years they don't name a syndrome foam lung or something like that, like coal miners have black lung disease," Nelson says.

How to Dispose of Floral Foam

Properly disposing of floral foam can go a long way toward preventing more microplastics from contaminating air and water. Feldmann notes that in a survey of professional florists conducted by the Sustainable Floristry Network, 72% of those who use floral foam admitted to disposing of it down the drain after the flowers die, and 15% said they add it to their garden and soil. Plus, "floral foam has found its way into the natural environment through different routes: buried with coffins, through the water system in vase water, and disposal into green waste systems, gardens, and composts when intermingled with the flowers," says Feldmann.

If you need to dispose of floral foam, experts agree that placing it in landfill garbage is much better than washing it down the drain or adding it to compost or yard waste. When dumping out water with floral foam fragments in it, Feldmann's advice is to "pour it through a tight weave fabric such as an old pillowcase to capture as many of the foam fragments as possible."

Floral Foam Alternatives

According to Nelson, florists may choose to use floral foam because it's familiar and convenient, "Yes, it's inconvenient to remember your reusable grocery bags in your car," she says. "But we all need to let go of the convenience mentality to have a more sustainable future, and just work a little bit harder to create less of an impact on the earth." Nelson adds that many florists also may not be aware that better alternatives exist.

Oasis itself now offers a fully compostable product called TerraBrick. The new product is "made from plant-based, renewable, natural coir and a compostable binder." Like Oasis floral foam, TerraBricks absorb water to keep flowers hydrated while supporting the stems in an arrangement. Then, the coir-based product can be composted and used in the garden safely. Another new option is Oshun Pouch, created in 2020 by CEO Kirsten VanDijk of New Age Floral. The pouch is filled with a compostable material that expands in water to support even the largest casket spray, says VanDijk.

There are even more ways to help support flower arrangements, including floral frogs, chicken wire, and decorative stones or beads in the vase. Or you can get creative with whatever is on hand, as VanDijk proved when she made her first sustainable design for a garden club. Instead of floral foam, "I cut a watermelon in half and put a couple of birds of paradise in it." A watermelon obviously won't last as long as floral foam, but that's kind of the point. VanDijk says it worked perfectly for a design that only needed to hold up for a day.

With more alternatives like these at your fingertips and a growing awareness of floral foam's negative impacts, it's clear that getting on the #nofloralfoam trend is a no-brainer. Perhaps that's why, as the floristry industry works to improve its sustainability overall, TJ McGrath of TJ McGrath Design thinks that "eliminating floral foam is top priority."

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