How sustainable is it to replace polystyrene with this mushroom packaging?

We all read the news some two years back: “Mushroom material are the new polystyrene. A great victory for nature!”

Dell and a bit later Ikea jumped on the Ecovative train. But now, in 2019, the dust seems to have settled a bit and it’s time for some perspective.

How sustainable is this replacement?

Below are a few questions you’ve probably been asking yourself.

1. How big is the original problem?

There is no doubt that polystyrene is a huge problem. It is a lightweight plastic which gets washed into the oceans easily and once there, photodegrades into smaller particles like the infamous ‘microplastics’. Such particles can be found in all the oceans and in fat tissue of humans, animals and in land-based aquatic environments.

Reducing the amount of polystyrene in the environment by developing a replacement is definitely a good idea.

2. Eco-friendliness: is the global footprint smaller than the footprint of the original?

Maybe…

How is mushroom packaging material produced industrially?

You need to grow so-called “substrate”. First, you need to moisten agricultural waste and put it in a plastic bag. Second, you heat treat the bag, at least at 65°C for a number of hours. Immediately after, cool down the hot bag and inoculate with strictly axenic inoculum under a Laminar Air Flow. You could attempt to combine all above steps in bulk, but don’t try it at home. It’s complicated. Then, for a number of days, incubate the bags under controlled temperature. At the end of this incubation phase, transfer the bag content to a plastic or silicon mold, again under cleanroom conditions and initiate the second incubation phase under controlled conditions. Finally, when the substrate is fully incubated, dry your object in an oven. Now you can sell it.

Each one of the above steps requires a high level of technical and technological knowledge. We can teach you most of it in our school, but not everything.

How is polystyrene packaging material produced?

This refined oil derivate results from a polymerisation of styrene. This is industrially made by alkylation of benzene and ethylene and it is expanded to ‘grains’. These are then expanded and molten together.

Which one consumes less energy?

We didn’t make the calculation, but you would expect someone to come up with numbers. But we can already tell you that according to our 40 years of experience, making substrate is a high-energy industry, making end products high value. Nobody just discards substrates as a waste product.

3. So how about CO2?

Are mycomaterials a carbon sink?

They are, but with a footnote.

During growth, fungi release CO2 and consume O2, just like animals. However, quite some carbon remains trapped within the mycomaterial itself. The total balance is positive, but not as a result of fungal growth. The fungal growth actually has a negative net impact on carbon storage in these materials. But we need to consider the complete picture:

a lot of carbon remains trapped in the plant materials
when replacing products such as polystyrene, there is a large CO2 benefit
using fungi as an advanced binding agent relieves us from using glue

4. How achievable is the solution?

In other words: can this product be produced industrially, in sufficient numbers?

The answer would be ‘yes’, but it will take a huge amount of R&D investment. Solid state fungi are notoriously difficult to cultivate. Anybody serious who has ever been involved will agree: if you thought tomatoes were hard, try fungi and think again.

There are also still loads of unknowns such as:

Ideal mycelial culture – Ideal substrate composition
Bulk inoculation and incubation method development
Sterility and corresponding production losses
Product flow
Energy savings

In other words: a pilot plant like Ecovative’s will have to overcome huge obstacles in order to become financially independent. Most of these obstacles can be overcome, but it would take between 5 and 10 years to do so. There are few companies that are prepared to take such a financial risk.

5. How affordable is the solution?

Too bad for the mycelium materials, but it will most likely never beat polystyrene, unless if oil becomes much, much more expensive. Again, there are many reasons why:

Cost of raw materials, especially spawn
Cost of the production facility
Incubation time = rotation time of a few weeks
Energy needs
Labour intensive

No matter how clean, considerable losses are commonplace in the production of fungi. They are living organisms and have to deal with a very well adapted and omnipresent competition. Losses of 5% are not unusual and this has a huge effect on cost.

There is a need for a proper LCA (Life Cycle Analysis) in order to address the ecological value of the product. Some attempts for such LCA’s have already been made, but we are still not entirely convinced.

6. So what is the final balance?

Mushroom materials are definitely a promising product type.

Mushroom materials as such have existed for a very long time, but only recently, people have started searching for alternative applications. One of these many applications could be packaging, but is this the most promising one? Most likely not, unless we start thinking differently about packaging. Right now, it is a disposable and is treated as such. But this could change if packaging was not made to be thrown… just a thought.

By Kasper Moreaux, Mycelia