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Floral foam: How bad is the stuff at the bottom of your roses?

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If you are lucky enough to receive flowers this Valentine’s Day, you may also get something not so rosy: a chunk of wet green foam.

Floral foam is widely used because it’s extremely useful.

By anchoring flower stems in it, florists can build enormous and sometimes gravity-defying arrangements.

The foam also soaks up water which improves the longevity of the flowers.

The problem is the foam has a longevity of its own.

Plastic takes hundreds of years to break down – some experts even suggest they may not break down at all in landfill. If you put the foam in the bin, that is where it will end up, and likely stay.


But many florists put the foam down the sink, according to Melbourne florist Rita Feldmann.

University of Adelaide molecular pharmacologist Dr Ian Musgrave said like putting any plastic in the waterstream, washing away floral foam was a bad idea.

"I would not flush it down the sink," he said.

"It’s probably not going to be very toxic, but you’re just adding more inert materials to the waterstream which can potentially have averse effects. Not because they are toxic, but organisms can eat this stuff."

Ms Feldmann and a growing number of florists, congregating around the Instagram account @nofloralfoam, are concerned about the health and environmental impacts of the foam - which is used in enormous quantities every year, and then promptly thrown out.

"It’s everywhere. You go to a supermarket, grab a block of flowers, it’s in the bottom. At races, weddings, it’s all foam," she said.

"Unfortunately it is very hard indeed to find any scientific research to either allay or confirm our suspicions about floral foam," said Shane Connolly, who is a florist to the British royal family and made arrangements for the Duke and Duchess of Cambridge’s 2011 wedding.

"What we do know is that it is not biodegradable - and that it contains known carcinogens."

The material itself is called phenol-formaldehyde foam, and it’s one of the oldest types of plastic. It’s made by reacting phenol and formaldehyde with each other to produce the plastic.

Air is then added to turn it into foam.

That foam is treated with detergents to give it the unique ability to soak up water.

The foam is made with two toxic chemicals, but is not necessarily harmful.

There is almost no phenol or formaldehyde left in the finished product – less than 0.1 per cent of each chemical.

“The foams are not particularly toxic. Formaldehyde is used in the make, but unlike household insulation where there are large chunks that could potentially leak formaldehyde, these blocks of foam are usually very small," Dr Musgrave said.

You probably should avoid eating the foam, and florists should avoid breathing in any dust generated when cutting it - but those were normal safety precautions for any plastic, he said.

Professor Ian Rae, a chemist at the University of Melbourne, suggested the foam might pose a risk if large amounts were kept in a sealed area for a long time.

“But the material safety data sheet (supplied to florists with the foam) said specifically keep it in a well-ventilated area. I had a sniff and couldn’t smell any formaldehyde,” he said.

Ms Feldmann said it was up to consumers to ask for foam-free flowers.

“I do huge aerial installations, and I’ve just invested in simple bits of [framing] and reused them for weddings. And I’ve probably saved hundreds of kilos of foam.

“There are certainly some designs that couldn’t be done without it – but we had flowers before we had foam.”