Biomaterials have the potential to significantly cut carbon emissions but designers should approach them with caution to avoid creating a whole new set of problems, warns Sioban Imms.

The vision of a civilisation based on biomaterials is compelling: products, clothes and buildings made from materials that have been "grown", rather than derived from polluting, extractive fossil industries. The promise is not only lower emissions, but products that are more in tune with the environment – manufactured objects that are part of the natural cycle of life. And consumers are willing to pay a premium for such ostensibly "sustainable" products – 12 per cent more, according to a recent study by Bain.

However, in a bid to gain competitive advantage, marketing narratives surrounding biomaterials are regularly inflated or gloss over important details. Prefixing "bio" to a material name conjures a sense of being natural, compostable, and better all round for personal and environmental health.

Marketing narratives surrounding biomaterials are regularly inflated

But these claims can unravel, or at least become complicated, when researching a little deeper than the material classification, product name and strapline. A report from RepRisk found a 70 per cent increase in incidents of greenwashing between 2022 and 2023. Incoming legislation in the EU is specifically targeting this issue.

The definition and terminology around biomaterials is still evolving. For clarity, we're not talking here about biomaterial designed for implanting into the body, but biologically derived materials used in product, fashion and architecture.

Often grown using living micro-organisms like yeast, bacteria, cellulose and mycelium, they can be finely tuned at the nanoscale by engineering DNA sequences to produce specific properties. For example, UK company Colorfix tweaks the DNA of bacteria so that they excrete coloured pigments for dyeing textiles. Microbial manufacturing organisms like these tend to be fed, fermented and modified in controlled environments.

The substitution of fossil-derived, high-carbon materials for biomaterials is urgently important. A recently published study by Radboud Universiteit in the Netherlands concluded that biomaterials reduce greenhouse-gas emissions by an average of 45 per cent compared to fossil-based materials.

But biomaterials are not a magic bullet to the multi-faceted nature crisis industrial civilisation is causing. Especially important is avoiding what are sometimes called "regrettable substitutions" – whereby one material is replaced with another that merely introduces a new set of problems.

For example, BioCane disposable food packaging is an alternative to plastic food packaging made from bagasse – pulped sugarcane-fibre, a waste product from the sugar industry. The design is geared to express its natural origins and circularity, from the subtly flecked, neutral colour and matte finish to the embossed logomark featuring a plant within a gradated circle.

Biomaterials are not a magic bullet to the multi-faceted nature crisis

However, for BioCane to be grease repellant (so it doesn't fall apart before you've consumed the contents) it needs an oleophobic coating, unlike plastic packaging. BioCane uses a polyfluoroalkyl substance (PFAS) for this coating. PFAS are termed "forever chemicals" due to their damaging long-term persistence and accumulation in the environment – not to mention our own bodies.

BioPak, which produces BioCane, transparently publishes information about this on its website, highlighting it as an industry-wide problem. The company also includes a timely pledge to phase out PFAS-containing packaging by June 2024, which happens to coincide with a move to phase out PFAS by the Environmental Protection Agency in the US.

Not all manufacturers are as responsible; it's common to find unlisted additives – or perhaps a fossil-based lamination to improve a material's durability – under a headline claim of biological origins.

Bioplastic is another material experiencing significant growth, partly driven by high oil prices making fossil-fuel-derived plastic less competitive. Most bioplastic is made from ethanol, commonly sourced from corn, wheat or sugarcane. Sugarcane, for example, is planted in monocultures in tropical and sub-tropical countries like Brazil. The sugar is extracted, fermented and distilled to produce precursor chemicals for bioplastics.

But to assess the environmental value of using this bioplastic, we need to know about how the crops are managed – for example, the pesticides and synthetic fertilisers used to increase crop yield, the land-clearance practices, and the effect on food prices if the bioplastic became widely adopted. At the end of the product's life, specialised infrastructure for disposal will need to be in place, further complicating the picture.

Biodegradable bioplastic would seem to offer a solution to the worst ravages of plastic – the alarming buildup of microplastic pollution across the world. How much better if the material could be absorbed back into the environment?

Biodegradable doesn't mean a material will break down in the environment over useful timescales

The market opportunity for biodegradable plastics is alluring, and forecasts predict that they will account for the majority of the bioplastics market – 62 per cent, by 2028. This opportunity is attracting investment and also the potential for greenwashing as companies vie for a competitive advantage over others.

But biodegradable doesn't mean a material will break down in the environment over useful timescales. A 2022 UCL study of supposedly "home compostable" bioplastics revealed that 60 per cent did not fully degrade within the tested timespans – a finding that unravels the whole purpose for investing in compostable packaging.

Claims relating to bioplastics were at the crux of a recent legal case brought against US biotech firm Danimer Scientific Inc. The manufacturer of biodegradable products had claimed that its proprietary plastic material Nodax PHA is able to biodegrade not only in industrial composting facilities but in landfill and in the ocean.

Danimer's share prices rocketed, sparking an investigative report in the Wall Street Journal, which stated that "many claims about Nodax are exaggerated and misleading, according to several experts on biodegradable plastics". Danimer refutes this statement, but what came out in court was that the company performed biodegradability tests on Nodax in a powdered form, which doesn't relate to real-world product formats like bottles that have variable thickness.

The legal case was eventually dismissed, but nonetheless the alleged greenwashing spiked Danimer's share price, shaking investors' trust in the company and having knock-on effects for the wider industry.

Going forward, manufacturers will need to be transparent about what goes into their products. In the EU, legislation tackling greenwashing in product labelling will come into effect in 2026. The new law is a direct response to the rise in misleading claims that companies use.

When specifying a biomaterial, it's important to dig into its provenance

It comes after a study commissioned by the bloc found that 53 per cent of green claims on products and services are vague, misleading or unfounded, and 40 per cent have no supporting evidence. In the UK, the Competition and Markets Authority has published the​​ Green Claims Code – a six-point guide to help businesses ensure they are not unwittingly misleading customers.

These two initiatives highlight the importance of using the right language when promoting products and materials, and as the impact of the EU's legislation ripples through the industry, there will be a natural calibration to more transparency.

The takeaway for designers is that, as ever, the picture is complex. When specifying a biomaterial, it's important to dig into its provenance, as well as to look at the material use and disposal. The allure of the "bio" prefix from an ethical – and marketing – perspective may be strong, but must be taken along with some healthy scrutiny.

Sioban Imms is a colour, material and finish (CMF) and sustainability strategist with a background in design and manufacturing. She is co-founder of consulting agency Substance and a contributing editor at trend forecasters Stylus and WGSN.

The photo, of MarinaTex designed by Lucy Hughes, is courtesy of the University of Sussex.

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