Designing for the environment—sustainability in plastic products
There are many different aspects to consider in guiding the individual to suitable oral hygiene products: the patient’s oral status, abilities, preferences and motivation, as well as the design and efficacy of the device. Where does environmental impact fit into the equation?
All dental professionals are aware of the importance of plaque control for sustaining periodontal health; successful prevention, treatment and maintenance are all dependent on control of the biofilm. To enhance patient compliance and achieve positive results, it is central to recommend hygienic, safe, durable and user-friendly products, efficient in reducing plaque without damaging either soft or hard tissue. Apart from the factors mentioned, there is another critical aspect to consider, the sustainability of the product. A high-quality product lasts longer and contributes to less waste. However, the material used, often plastic, has a decisive role from an environmental perspective. Let us look further into this matter.
Assessing the environmental impact
Plastic products and their environmental impact, also known as the carbon footprint, are currently high on the agenda. However, designing a product with a small and long-term sustainable environmental footprint is not merely about using recycled material or stopping plastic use altogether. All too often, initiatives to reduce the footprint of a product—using paper or fabric bags instead of plastic bags for instance—focus on one single aspect, disregarding other factors which may affect the environment even more.
A useful tool for evaluating the impact is life cycle assessment (LCA), which is a way to systematically analyse the environmental effects of different materials and energy throughout their life cycles. LCA can provide a more accurate picture of the carbon footprint that a product leaves behind on its journey from cradle to grave.
The greenhouse effect
LCA results in suggested measures to reduce the footprint, together with an analysis of the impact expressed as the global warming potential (GWP). As different materials are incinerated, greenhouse gases are released into the atmosphere, where they absorb energy and warm the earth like an insulation blanket. The GWP is a calculation of this effect. Reducing the emissions of greenhouse gases can be a question of using limited amounts of materials or materials with lower impact; in either case, it is essential to see the big picture.
Like many methods of analysis, LCA has its limitations. Not every factor can be translated into a number or fitted into a model, and LCA does not generally account for social implications. Despite this, LCA is the closest there is to an efficient instrument for comparing the environmental effects of materials or processes. The GWP provides a standard unit of measure and is used by a growing number of suppliers and manufacturers.
Changing from fossil to bio-based resources
Plastic materials are still supreme in terms of hygiene, safety, quality, malleability and cost-effectiveness. However, as fossil resources are becoming scarcer and more expensive, the world of plastics is shifting towards alternative resources which can be generated quickly enough to keep up with the demand. There is a wide range of bio-based resources that can be turned into bioplastics, for example cellulose, castor oil plant and sugar cane; however, a bio-based plastic does not necessarily generate a smaller footprint than does a fossil-based plastic, which LCA shows. For example, a conventional plastic wrapping in the form of a toothbrush flow pack made from fossil-based polypropylene has a GWP of 3.3 kg CO2 eq/kg. The same wrapping can, without any technical changes, be made from bio-based cellulose film, which has a higher GWP, 5.05 kg CO2 eq/kg.
In many industries, it will take significant investments as well as innovative techniques to shift towards renewable raw materials. Different materials behave differently, and sometimes existing machines and moulds can be utilised, but in many cases, the development and purchase of new devices will be needed.
Another factor to consider is the relatively high difference in price between fossil and renewable materials. The renewable option of polymer polyethylene is almost double the cost of fossil polyethylene, a common material in products and packaging. However, with rising demand for bio-based plastics, both accessibility and affordability will increase.
Recycled and biodegradable plastics
Why not just use recycled plastic? It is applicable in many cases, for example in packaging materials, but is problematic to use in oral hygiene products. Strict regulations dictate 100% control over product contents by the manufacturer, and recycled plastic that comes from different sources runs the risk of containing hazardous chemicals. A varying standard of plastic also affects the product quality.
Could biodegradable plastics be an option to reduce plastic waste? Biodegradable plastics can be degraded by microorganisms, but are not necessarily bio-based; they are often made from oil in the same way as conventional plastics. These kinds of plastics should be used only when there is a specific need for decomposition after use, like in certain kinds of food packaging, or for agricultural and medical use (e.g. sutures and capsules).
The best way to help save the planet is to save energy and improve methods of recycling and recovering all plastics. It would be a mistake to focus on making it easier to discard plastic products irresponsibly in the name of the environment.
Designing for a sustainable future
Renewable plastics are the future, but as you now know, true sustainability can only be achieved by looking at the full life cycle of a product. Let us take another example from the world of oral hygiene: a toothbrush handle made from bio-based polyethylene.
Bio-based polyethylene made from sugar cane, a neverceasing resource, has a footprint that is nearly negligible: firstly, because the sugar cane is cultivated and the plant absorbs CO2; secondly, owing to the processes involved in turning the sugar cane into ethanol and then into polyethylene; after that, because of how the plastic is transported, how the toothbrush is manufactured (using green energy from solar panels, for instance) and then transported to the end user. After use, it is disposed of in the household waste, which is ultimately incinerated (and ideally turned into district heating). Throughout the toothbrush handle life cycle, 95% of the carbon is recycled, meaning that its contribution to global warming is minimal. A step towards a sustainable future has been taken—without compromising on quality.
A mutual responsibility
Of course, these conclusions regarding the footprint of bioplastics assume safe and responsible disposal of the products after use. Producers who assume environmental responsibility are dedicated to working towards constant environmental and social improvements and taking measures to minimise the use of energy and materials in their products and packaging. However, it does not end there. Dental professionals advising their patients have the opportunity to influence patients’ choice of high-quality and long-lasting products and what happens to the product when their purpose is fulfilled. Waste that does not belong in our oceans should be prevented from ending up there by any means—and that is everyone’s responsibility.
Editorial note: This article was published in prevention—international magazine for oral health vol. 4, issue 2/2020.