Greening the Red List: Nature-inspired chemistry innovations for the building sector
By Mark Dorfman, Biomimicry 3.8 Senior Principal and Chemist
PVC. Flame retardants. Epoxy. They’re materials we’ve all heard of, and live around every day. The problem? They’re top offenders when it comes to toxins used in the building sector. In fact, they’re on the International Living Future Institute’s (ILFI) top five chemical categories most in need of new, life-friendly,* innovative alternatives.
PVC siding protects from environmental factors, but there are environmental and public health issues associated with the manufacture and post-consumer management of PVC.
Lady bug exoskeleton protects from environmental factors yet the processes and materials involved in its production, use, and post-use management are life-friendly.
Conventional wood adhesives off-gas toxic chemicals that contaminate indoor air.
A natural adhesive strategy that is life-friendly (except to bugs caught in the sticky trap) throughout its life-cycle.
Toxic flame retardants are applied to furniture. They contaminate indoor spaces as furniture materials degrade.
Natural flame retardant strategy: Tinder mushroom smolders but won't burst into flame.
That’s where biomimicry comes in. For more than 3.8 billion years, organisms have developed chemical strategies that solve for the same functions our toxic chemicals serve in the built environment (e.g., waterproofing, light-weighting, adhering, protecting from environmental factors, etc.), but they do so without introducing unintended toxicity. And that’s by design—organisms have to make, use, and manage chemical resources where they survive and thrive. Biomimicry taps into the design principles and deep patterns underlying nature’s elegant, life-friendly chemistry to inform innovative and effective solutions.
Red List chemicals | ILFI is a nonprofit working to build an ecologically-minded, restorative world for all people. ILFI runs the Living Building Challenge, which is the world’s most rigorous green building standard. ILFI’s Living Product Challenge takes the robust concepts of the Living Building Challenge and applies them to manufactured goods. Manufacturers are using the Living Product Challenge framework to rethink the way products are made. Instead of trying to be “less bad,” they are creating goods that have a positive impact. Developed by ILFI and one of the Imperatives of the Living Product Challenge, the Red List contains the worst in class materials prevalent in the building industry. More information on each of the 20 Red List chemicals and chemical categories listed below is available here; a list of 800+ specific chemicals within these 20 categories can be found here.
Alkylphenols
Asbestos
Bisphenol A (BPA)
Cadmium
Chlorinated Polyethylene and Chlorosulfonated Polyethylene
Chlorobenzenes
Chlorofluorocarbons (CFCS) and Hydrochlorofluorocarbons (HCFCS)
Chloroprene (Neoprene)
Chromium VI
Formaldehyde (Added)
Halogenated Flame Retardants (HFRS)
Lead (Added)
Mercury
Perfluorinated Compounds (PFCS)
Phthalates
Polychlorinated Biphenyls (PCBS)
Polyvinyl Chloride (PVC), Chlorinated Polyvinyl Chloride (CPVC), Polyvinylidene Chloride (PVDC)
Short Chain Chlorinated Paraffins (SCCPS)
Volatile Organic Compounds (VOCS) in Wet Applied Products
Wood Treatments Containing Creosote, Arsenic or Pentachlorophenol
The Biomimicry and Chemistry blog | ILFI has identified five Red List chemical categories most in need of innovation: PVC, flame retardants, bio-based material alternatives, composite wood or agrifiber products, and epoxy. This series will focus on the five Red List chemical categories, reporting on one category in each blog post. Each post will describe:
how and why these chemicals are used in the building industry (i.e., the function they serve),
the public health and environmental issues associated with their manufacture, use in the built environment, and post-consumer management, and
thought-provoking strategies in the living natural world that organisms use to solve for the same function.
Chemistry’s starring role in the natural world | Many people misconceive “chemicals” as man-made entities that contaminate an otherwise chemical-free natural world, but nothing can be further from the truth because nature is literally alive with chemistry!
Every color, flavor, fragrance, fiber, remedy, nutrient, and material we value from the natural world has its basis in chemistry. After 3.8 billion years of life on Earth, all living organisms—from amoebas to zebras—use sophisticated, elegant, life-friendly chemistry to thrive in the face of challenges posed by their surroundings.
What might seem surprising is that the functional challenges faced by organisms living in age-old ecosystems align with the functional challenges faced by humans living in modern surroundings. These functional challenges include:
building structures that maximize strength while minimizing material,
forming coatings that protect from moisture, fire, heat, cold, ice, wind, UV radiation, and other environmental factors,
adhering materials,
lubricating or otherwise protecting from abrasion,
resisting or fighting infection,
protecting from oxidative stress,
managing materials after intended use, and
communicating through sending and receiving signals.
The toucan’s beak is an example of light-weighting in nature (i.e., maximizing strength and resilience while minimizing material).
Chemistry plays a vital role in solving for each of these challenges, but the chemical strategies developed by organisms over the eons is, by necessity, life friendly. After all, organisms have to make, use, and manage chemicals, chemical processes, and resulting materials in the same place they raise their young. Polluting the surroundings, or generating life-unfriendly heat or pressure, is simply not an option for organisms. Nature does make toxic chemicals, but unlike many man-made chemicals that carry unintentional toxicities along with their primary function, nature’s chemicals are toxic only when toxicity is the intended function, such as for protection and predation. Even then, the toxins break down in relatively short order.
Comparing nature’s chemical strategies to ours | With 3.8 billion years of R&D under it’s collective belt, Life on Earth has developed a remarkable array of innovative problem-solving strategies. Humans, on the other hand, have only had several hundred years since the beginning of the industrial revolution to develop the chemical technologies in use today. Don’t get me wrong—going from stone tools to iPhones within a handful of centuries is no small feat. But imagine where our technology will be after a thousand, million, or hundreds of million years. That’s the level of technological development that can be found in nature.
More than 3.5 billion years ago, colorful bacteria developed photosynthesis—the process of using sunlight, water, and carbon dioxide at ambient temperatures and pressures to knit carbon atoms together into sugars. It’s a process that cascaded into the development of every other biological compound we value today. If 3.5 billion years ago, nature “invented” a chemical process as sophisticated as photosynthesis, magine what chemistries nature has developed since then to solve functional challenges.
Take solid structures, for example. Coral is a hard, cement-like material that is produced at ambient temperatures using dissolved minerals present in the marine environment. Specialized biological molecules facilitate the gathering, concentrating, and precipitation of orderly arranged mineral crystals into hard coral. Man-made concrete, on the other hand, requires mineral mining, transport, and prolonged, intense heat to form cement. The living natural world has something to teach us about the chemistry of making hard materials to meet structural challenges.
Conventional cement production requires prolonged heating at over 1,000 oF (photo © Walter Baxter (cc-by-sa/2.0))
Hard corals are produced at ambient temperature and pressure.
The living natural world also has something to teach us about innovative approaches to protecting from mechanical wear, as shown in this example of an organism protecting itself from abrasion. The sandfish skink buries itself and slithers around while immersed in dry sand. It resists abrasion under these harsh conditions by decorating the polymers making up its scales with sugar molecules. This chemical intervention reduces the attraction between the scales and the abrasive sand crystals by reducing “van der Waals interactions”—an attractive force that only comes into play at very close, submicroscopic distances. Conventional means of reducing abrasive forces, such as between the moving parts of machinery, is achieved through lubricating fluids that are often petrochemically-derived compounds.
Sandfish skink “swims” through dry sand without abrasive wear. (photo: FinnHK)
Biomimicry is a powerful problem-solving tool | Biomimicry is a systematic approach to solving problems through innovation inspired by nature. It’s a process designed to reduce a given problem down to its core function and then filter-feed through scientific literature to pull in all relevant natural strategies. For example, PVC siding protects a building from harsh environmental conditions. The biomimetic approach to finding alternatives to PVC siding would be to investigate the strategies organisms have developed to protect themselves from the same conditions. The scientific principles underlying those natural strategies spur novel design ideas for innovative solutions.
Biomimicry is uniquely suited to identifying the key chemistry principles underlying strategies in nature around a given function because it looks across species to tease out deep patterns. This is critical because most biological chemicals and materials are multifunctional--they fulfill more than one need--so biomimicry is able to tease out, and home in on, the principles associated with the specific function of interest. Click here to download a description of the research methodology developed at Biomimicry 3.8.
*life-friendly innovations rely on chemistries that, throughout their life-cycle, do not adversely disrupt the biochemical processes of living organisms.