What is the Best Material for Your Lunchbox? This Technical Article Explains All

December 10, 2020

A Technical Comparison of Plastic, Stainless Steel & Bamboo Materials when used to make Food Containers

What is the Best Material for a Lunch Box?

Why do we use stainless steel in our lunchboxes and bottles? We recognise it as the best material to make a useful product that will last a long time and have the least impact on the environment and our health.

Here we take a more in-depth look at the main contenders for materials for food containers and consider their merits and drawbacks. We are under no illusion, there is always a certain amount of resources required to make anything and the choice you make is dependant on the application.

What follows are summary points of a very large and difficult subject, simplified to give an overview to help educate and inform. It consists of research that has been done by others and shared in the public domain. If you would like to dig deeper on any of the points, the references are given below.

We focus in the following three areas:

1) Energy impact of the material creation, production and distribution
2) Recyclability
3) Lifecycle

What is your lunchbox made of?

Plastic

1. Energy Impact of the material creation, production and distribution

* “In order to produce plastic products, energy resources are consumed. Currently such energy resources are almost entirely obtained from nonrenewable sources and by using them, greenhouse gas (GHG) emissions are produced. Nevertheless, even more energy would be consumed and more GHG emissions emitted, if plastic products were to be substituted by alternative materials.”[1]

* “In addition, some plastic products enable energy savings to be made during their life-cycle, even without being compared with other materials. Examples are insulation materials (valid in fact for all insulation materials), wind-power rotor blades, plastic packaging materials that reduce food losses or help avoid damage to durable goods (valid to some extent for other packaging materials), new products substituting heavier plastic products, and products that incorporate improvements by ongoing innovation, concept changes and dematerialisation.”[2]

* “In all fairness, no plastics are made from crude oil. They are made from feedstock that is derived from crude oil, for sure, but not straight from oil. Of course, this does not have any bearing on their environmentally unfriendly properties: whether its derived from crude oil or from a crude oil feedstock, plastic still takes centuries to degrade, and in the meantime, thanks to wind and rain, they shed tiny particles that enter the food chain.”[3]

* “Interestingly enough, many plastics are actually made from natural gas feedstock. In the United States, for example, the most common feedstock for plastics, be it for packaging or anything else, is natural gas liquids, liquid petroleum gases, and natural gas.”[4]

* “Plastics production accounts for about 4 percent of global oil production. That’s according to figures for 2012, so now it may well be higher.”[5]

* “A 2017 report on global plastics found that plastic production in the United States was growing at an annual rate of 1.6 percent, while China was producing 3 percent more plastics every year on average. According to the same report, plastics for packaging constituted 19 percent of the total plastics production in 2016--the second largest segment after “Other Plastic Products”.[6]

* “Until we find a reliable and cost-competitive alternative to these sorts of plastic packaging, the point of how much oil—or gas—goes into plastic packaging is moot.”[7]

2. Recyclability

* “Plastics take an awfully long time to decompose naturally, and only a small amount of the plastics used on a global scale gets recycled. The problem is serious.”[8]

* “The problem with recycling plastic is that it doesn’t really happen. For example, plastic litter is not separated during collection in The Netherlands. It can’t be used to make the same products again; for example, food packaging that is recycled cannot be used again as food packaging.”[9]

* “ Until recently, some of the western world’s plastic waste was exported to China to be recycled. China, however, no longer wants our plastic rubbish. The flow of rubbish has shifted to other Asian countries, but they, too, are beginning to implement restrictions or are closing their borders to foreign plastic waste. Countries need to deal with their own plastic waste. In theory, all plastic can be used again. The suggestion, however, that the issue of plastic pollution can be solved through recycling is a myth. In reality, only 9% of all plastic in use worldwide is recycled, and the majority of this recycled plastic is of inferior quality. The process of recycling is, for the time being, downcycling, which results in an undiminished use of new or ‘virgin’ plastic.”[10]

3. Lifecycle and Lifespan

* “About half of all plastic on earth has been produced in the last thirteen years. If the current trend continues, around the year 2050, there will be about twelve billion tons of plastic in landfills and in the environment. More plastic is being thrown away than we can clean up, even though we are doing our best. The only way to reduce and prevent plastic pollution is to produce and use much less plastic.”[11]

* “Larger pieces of plastic in the sea or on land, such as bottles and plastic packaging, become brittle and gradually break down. This is due to sunlight, oxidation or friction, or by animals nibbling on the plastic. This plastic break down process goes on forever, although the speed depends on the circumstances. There are beaches where you not only see large pieces, but also countless fragments, colored or faded — the smallest pieces can no longer be distinguished from grains of sand. Fragments become microplastics and microplastics become nanoplastics. The latter are so small that they are barely visible even under the most advanced microscopes.”[12]

* “All these small particles of plastic never fully decompose and are literally everywhere: in water, soil, and air. Because they are light, they are easily transported across long distances. In 2014, it was discovered by accident that polar ice appears to be full of microplastics. It was then assumed that microplastics were carried along with ocean currents and then caught up in the ice. It is now clear that microplastics are also carried by the wind. It ‘rains’ microplastics every day…”[13]

* “It has become evident that microplastics can no longer be completely removed from the natural world. This would not be a problem if we were sure that they are harmless in the environment. The point is that there are various indications that they are harmful. What we know is that all animal species, including humans, ingest them and that the smallest particles – the nanoplastics – can spread throughout the body and possibly reach the organs, including the brain. We also know that the concentration of these small particles in the environment is increasing, and it’s likely that the concentration of particles in humans is likely doing the same. There is no escaping it, and we can only hope that the consequences in the short and long term are better than expected.”[14]

Stainless Steel

1. Energy Impact of the material creation, production and distribution

* “Ferroalloy production and the fabrication of stainless steel in electric arc furnaces are energy-intensive processes. By examining the energy requirements to produce stainless steel throughout the entire life cycle, and isolating the effect of scrap recycling on energy use, one can understand the true energy needs and opportunities for conservation. The World Commission on Environment and Development (1987) found that a ‘‘low energy path is the best way toward a sustainable future’’. Determining the energy intensities of materials (i.e., the energy required per unit mass) under different scenarios aides in understanding and identifying this low-energy path.”[15]

* “Methods for manufacturing steel have evolved significantly since industrial production began in the late 19th century. Modern methods, however, are still based around the Bessemer Process, namely, how to most efficiently use oxygen to lower the carbon content in iron.

* Today, steel making comes from both recycled as well as from raw materials. Two processes:
Basic Oxygen Steelmaking (BOS)/ Basic Oxygen Furnace (BOF) and
Electric Arc Furnace (EAF) account for virtually all steel production.”[16]

* “Steel production has a number of impacts on the environment, including air emissions (CO, SOx, NOx, PM2), wastewater contaminants, hazardous wastes, and solid wastes. The major environmental impacts from integrated steel mills are from coking and iron-making.”[17]

* “The stainless steel industry has proven to be extremely environmentally friendly. This is because it uses primary energy sparingly, saves non-renewable sources and limits the waste stream.”[18]

* “During production, stainless steel uses scrap metal as its primary raw material , with up to 70% of the product coming from recycled material. Increased efficiency in process technology has also decreased the amount of energy required to manufacture stainless steel.”[19]

2. Recyclability

* “A product which is made from stainless steel such as stainless steel wire or stainless steel banding will never become useless at the end of its life and this is because stainless steel can be separated systematically and thus can enter the recycling system.”[20]

* “Recycling is deemed viable when applied to stainless steel because within the stainless steel is iron, nickel, chromium all which are raw materials and so the process of recycling stainless steel is carried out globally all over the world.”[21]

* “Production and recycling are not separate stages in the life of stainless steel it is important to notice that they are one and the same process. Any stainless steel object has about 60% recycled content within it.”[22]

* “Stainless steel therefore isn’t consumed but is rather sustained; although it is recycled and thus produced it is important to note that it does not degrade in any way once recycled.”[23]

3. Lifecycle and Lifespan

* “Stainless steels have traditionally been specified in applications where the primary requirement is for corrosion resistance. However, since their invention over 100 years ago, stainless steels have also been recognised for other attributes such as durability, versatility, quality, sustainability, hygiene and aesthetic appeal.”[24]

* “Even if stainless steel is not recycled and it does find its way to a landfill or disposal site, it will have no detrimental effect to the soil or groundwater.”[25]

* “Stainless Steel is the preferred material for green building throughout the world. Its impact on the environment is minimal when compared to other materials and its life impact reduces significantly as it used and recycled.”[26]

* “Stainless steel may not always be the cheapest candidate material for an application when considering upfront costs. However, its durability and ease of maintenance compensate for the sometimes higher initial purchasing costs and it is often the least expensive choice in a life cycle costing comparison. This ability to provide long-term performance with a minimum of downtime and cost associated with maintenance is determined by calculating the material’s life cycle cost (LCC). Life cycle costing (LCC) is a technique developed for identifying and quantifying all costs, initial and ongoing, associated with a project or installation over a given period.”[27]

Bamboo

1. Energy Impact of the material creation, production and distribution

* “Bamboo is truly a wonder plant. It is a symbol of strength, flexibility, and sustainability. For many reasons’ bamboo, is often called ‘the world’s most renewable material’. It can grow up to one meter a day. This fast grower absorbs five times more carbon dioxide and produces 35% more oxygen than trees.”[28]

* “To grow like this, bamboo requires little water and neither pesticides nor fertilizers. When bamboo is harvested, the plant regenerates itself from its roots system. These root systems also prevent erosion and nourish the soil with potassium and other nutriments.”[29]

* “This renewable “Superhero” remains impressive when crafted into products. Its strength makes it the first choice to create scaffold in Asia. Bamboo has also natural anti-bacterial properties, which makes it an excellent choice for cutlery or straws. Improved techniques make it possible to create textiles from bamboo. Bamboo fibre is extremely soft, light weighted and a more sustainable alternative to cotton.”[30]

* “Why is it that then a plant is able to grow most places we still impart of Asia? My guess is because labour is cheap, just like with fast fashion, and actually lots of bamboos are not certified from third-parties which makes the production of it rather untransparent.”[31]

* “Bamboo can grow in places that would otherwise not have been fit for vegetation, like rocky hills and slopes, so ideally bamboo production would not have to replace natural forests. Bamboo also grows fast, much faster than trees. Where a tree can take 30-50 years to become big enough to be used as timber. Whereas bamboo will take about 3 years to get established, and then it will take the new shoots 60 days to grow to a proper size.”[32]

* “Bamboo has a lower carbon footprint than FSC certified tropical hardwood. Bamboo products imported to Europe have more eco-costs than local European softwood.”[33]

* “Because of the increased production of bamboo, as a result of higher demand from new consumers in Northern America and Europe, bamboo generates higher profit for farmers than trees, and that, although it sounds good, is actually a problem. In China, it was reported that many farmers where turned natural forests, fields, and farmland into bamboo forests. As a result that could be a problem for China’s food supply, as well as a problem for the environment. When you cut down natural forests, in order to produce a certain product you create a mono-culture, in this case, it’s bamboo and a mono-culture can have devastating effects on natural habitats for animals, diversity, soil quality, and microbial activity, all elements that need to thrive in order to have a functioning ecosystem. On report found that between the late 80’s and the late ’90s 23-30% of China’s national forests were converted into bamboo production.”[34]

* “(an) investigation revealed many environmental concerns associated with growing, harvesting, and converting bamboo to useful products. Problems reported throughout bamboo-producing regions included clearing of natural forests for the establishment of bamboo plantations; creation of monoculture plantations; loss of biodiversity; substantial use of fertilizers and pesticides despite claims that bamboo crops required neither of these treatments; and unsustainable harvesting of natural stands of bamboo. We concluded our earlier report with the observation that the unquestioned green status accorded bamboo products needed serious re-evaluation and that, at a minimum, third-party certification should be required before awarding any kind of green status to bamboo products.”[35]

* “not any bamboo product is as sustainable as it could be, and going tons of aesthetically pleasing bamboo products from cheap suppliers or eBay/Wish like shops are properly produced very poorly. So when buying a bamboo product find companies and suppliers that seem transparent about their products or that offer details like if they use fertilizer, if it’s organic, where it’s grown etc. But if we buy a bamboo spoon as use that hundreds of times rather than a disposable plastic spoon, it’s still more sustainable, because reusables products always beat a single-use product.”[36]

2. Recyclability

* “Bamboo products can be sustainable if they are reused and cared for, but disposable bamboo products that are just thrown away actually has a higher carbon footprint than plastic, and if it ends up in landfill it won’t biodegrade. The only upside is that it does not release microplastic and it is not based on fossil materials, but that’s a relatively low bar for sustainability. So reuse above all. At least to me, zero waste living is not only about refusing plastic but also refusing other single-use products, especially if they can be replaced with a reusable one.”[37]

3. Lifecycle and Lifespan

* “Processed bamboo fiber products are not always free from plastic and can make the materials harder to compost and they are not necessarily free from harmful chemicals just because there is bamboo in it.”[38]

* “The durability of bamboo is directly related to how well it is treated at all stages of its use, including how it is grown, harvested, dried, stored, transported, and installed. Well grown and harvested bamboo, protected from excessive rain, sun and ground contact can last for 10’s of years, while poorly treated bamboo may only survive a year or two at best.”[39]

* “At end-of-life, it is assumed that 90% of the bamboo products are incinerated in an electrical power plant and 10% will end-up in landfill, a realistic scenario for Western Europe.”[40]

* “Bamboo has an astounding strength and lifespan whilst remaining light and easy to carry around. With proper care, your bamboo goodies can be used time and time again without the worry of them deteriorating.”[41]

Summary

* Plastic is problematic in multiple ways. When it is recycled it cannot be used for food packaging, which greatly limits how it can be recycled. It is totally non-biodegradable, returning into our eco-systems in harmful ways.
* There is contradictory information regarding how much energy it takes to make stainless steel and how environmentally friendly the production is and will vary according to specific practices in place with different foundries. However, it is made from recycled materials, is sustainable and durable, making it a great reusable alternative to plastic.
* Bamboo is a great material in theory. But there is not enough regulations on the manufacturing of it yet. It is often used as a single-use plastic alternative due to its biodegradability – but it must be composted to do this, which few people actually do. This results in more energy consumption than plastic. Reusable bamboo products are a useful alternative – although the sourcing of the bamboo must be carefully tracked. The finished products are not as durable as stainless steel and will need replacing sooner.