What Floral Designers Don't Know About Floral Foam & Trays
Floral foam may be green in color, but it's certainly not green in practice!
WHAT IS FLORAL FOAM?
Floral foam is that ubiquitous damp green block you'll find at the bottom of floral arrangements at weddings, flower shops, funerals, grocery store floral/gift departments, horse races, auto races, and anywhere else cut flowers are used as decoration. It's super effective and convenient, and is central to the floral designing process. It stabilizes and supports flowers, and provides enough water for arrangements to last as long as 2 weeks. It comes in all sorts of shapes, sizes, and densities, allowing floral designers to let their imaginations and creativity soar. That's the good news. Here comes the bad news!

Floral foam is a type of phenol-formaldehyde foam, meaning that it's produced by reacting phenol with formaldehyde. Bakelite, a material created in the early 1900s and the first commercially viable plastic, is also a phenol-formaldehyde material. Phenol-formaldehyde foams ('phenolic' foams) are also used as building insulation.
Floral foam can absorb many times its weight in water because it is an open-celled foam Open cell foam is full of cells that aren’t completely encapsulated. In other words, the cells are deliberatly left open. This makes the foam a softer, more flexible material.
Closed cell foam is made up of cells that are, as the name suggests, completely closed. The cells are pressed together, so air and moisture are unable to get inside the foam. Because of this, closed cell foam is much more rigid and stable than open cell foam.
IS FLORAL FOAM TOXiC?
Floral foam is created with carbon black, phenol, and formaldehyde, which are all known carcinogens. However, less than 0.1 per cent of those chemicals remains in the finished product. (Sodium hydroxide (lye) is used to create bar soap, but none of it remains in the final product).
In my research, I found that activists and environmentalists argue that this product is awful and shouldn't be used by anyone, but the manufacturer counters that the research is shoddy and sensationalist, and there's nothing harmful at all about their product. But that's pretty much the case with most products that have received backlash due to their toxicity or environmental footprint - people complain about it, and the manufacturer dismisses the complaints as frivolous and inconsequential.
If you'd like to read more about the toxicity of floral foam, here's some suggestions.
'Foaming at the Mouth: Ingestion of Floral Foam Microplastics by Aquatic Animals' by C. Trestrail et al., published in Science of the Total Environment
The manufacturer's rebuttal to the above study: Oasis Floral Products Response to Publication by C. Trestrail et al.
The MSDS (Materials Safety Data Sheet) for the most commonly used floral foam: https://docs.wixstatic.com/ugd/898205_195723f870af4af5babdd47c476f79d2.pdf
Yvette Wolf on Medium, 'The Unknown Danger of Floral Foam (Oasis)'
IS FLORAL FOAM ECO-FRIENDLY AND SUSTAINABLE?
No. Not at all. I'll let you decide for yourself as to whether or not it's toxic to your health and if you want to wear gloves when handling it. However, its environmental foot print is unequivocally not good, and as a waste diversion professional, that's the topic I'm going to zero in on.

IT'S LANDFILL FODDER
You can't reuse it, you can't recycle it, and you can't compost it. Flowers and stems from weddings can be composted completely, but the damp floral foam block must be removed first, as it's essentially plastic soaked in various carcinogenic chemicals - we certainly don't want that in our compost. However, the block is fragile and often starts to crumble, making it difficult to remove it completely. That's a huge pain for waste diversion staff.
IT'S EVEN SCARIER WHEN IT STARTS TO BREAK APART
As a fine-celled phenolic foam, floral foam breaks easily into a green powdery microplastic. You're probably already familiar with the dangers of microplastics in our environment. From the Medium article we referenced earlier:
"(Oasis floral foam) is still being marketed as being bio-degradable. On the Oasis website, the product is 100% certified biodegradable within 567 days. Just a quick look at the MSDS will tell you this is not true.
It states that “this formulation has not been tested for environmental effects. It is a thermoset plastic and is not biodegradable.” It is not evident if this information has changed since the document was prepared in 2005. They suggest recycling the floral foam and using it as a soil conditioner (!!!), however this doesn’t seem like it would be a safe or healthy option, given the amount of hazardous chemicals it contains.
THE U.K.'s ROYAL HORTICULTURAL SOCIETY HAS BANNED FLORAL FOAM AS OF 2021
"Floral foam uses micro-plastics and is currently non-recyclable; with this in mind we have come to the decision to ban the use of floral foam at RHS Shows from 2021 and have asked that floral designers at RHS Shows this year trial alternative products where possible," says Helen Pettit, Director of Shows at RHS.
FLORAL FOAM TRAYS ARE ALSO NOT RECYCLABLE

Floral foam trays, at least in the United States, are made of #6 polystyrene, which is not commonly recycled in the vast majority of curbside bins or drop-off centers. It must be thrown away. It CAN be reused, but this is often not done. Most floral arrangement are tossed right after events, along with the foam and trays. Even if guests take the arrangements home, that just delays the inevitable. Instead of the venue throwing away the floral arrangement foam and trays, it gets thrown away at home.
SO, WHAT CAN BE USED INSTEAD?
If you want to steer clear of Oasis products altogether, Good Housekeeping Magazine has the following suggestions on floral foam substitutes:
Use pebbles, sand, gravel, clay, marbles, wood aspen, compact moss or even fruit to support floral arrangements.
Re-trim floral bouquets and change the water regularly to prolong flowers life.
Use a kenzan or flower frog – metal devices that sit in a vase or bowl and secure stems with metal needles or guide them into holes – vintage ones are available on Etsy.
Pliable twigs also make a good supportive lattice for flowers to be propped against.
Chicken wire or metal pins are fantastic for securing stems and act as a supportive grate when arranging straight into vases or planters.
OASIS NOW OFFERS TRULY COMPOSTABLE FLORAL MEDIA
The #1 producer of floral foam now has a product called TerraBrick that's plant-based, renewable, natural coir, and made with a compostable binder. Check it out here: https://www.oasisfloralproducts.com/pages/terrabrick-oasis-floral-media
And finally, make sure all those flowers from your event make it to a compost pile. Don't landfill them!
Flowers can be composted as yard waste and in backyards and home compost piles.