It’s Plastic-Free July, and at Aqua Libra Co, we’re thinking about some of the ways we can reduce single-use plastic. We’ve already had a look at chewing gum, teabags, and carrier bags. We’ve also talked about the innovative Refill app, which connects consumers with a growing number of businesses that provide unpackaged goods.
This time, we’re exploring the matter of plastic wrap – also known as cling film or cling wrap.
If you’ve ever completed a food hygiene course, you will have been told never to reuse cling film, due to the risk of cross-contamination. At home, you make the rules. However, even if you try to reuse cling film, it doesn’t perform terribly well after the first use.
Cling film is one of those plastic products that really is for single use.
In the UK, cling film is typically made from either polyethylene (also known as polythene) or polyvinyl chloride (better known as PVC). In the US, polyvinylidene chloride (PVDC) is the traditional cling wrap material.
Polyvinyl chloride is created via the polymerisation of vinyl chloride (C2H3Cl), a monomer that’s derived from petroleum. In the vinyl chloride molecule, the two carbon atoms are held together by a double bond. When this double bond is reduced to a single bond, each carbon atom bonds with a carbon atom from another vinyl chloride molecule, and so a polymer is formed – a molecule that comprises a long, repeating chain of C2H3Cl.
PVC was first synthesised by a German chemist, Eugen Baumann (1846-1896) in 1872. Due to its brittleness, it wasn’t a useful material. Then in 1926, an American inventor, Waldo Semon (1898-1999), found a way to plasticise polyvinyl chloride, which resulted in a more easily processed and more flexible material.
In 2018, 44,300,000 metric tonnes of PVC were produced globally.
Polyvinylidene chloride is a petrobased polymer synthesised from the monomer vinylidene chloride (C2H2Cl2), which was accidentally discovered in 1933 by John Reilly, an employee of Dow Chemical Company (based in Michigan, US). With his colleagues, Reilly went on to develop PVDC into a commercially successful material, which he called ‘Saran’, a portmanteau of Sarah and Ann, the names of Reilly’s wife and daughter. Saran wrap – still the best-known brand of cling wrap in the United States – was introduced to consumers in 1953.
Since 2004, Saran wrap has been made from low density polyethylene.
Cling film is commonly made from polyethylene, also known as polythene. The polyethylene molecule is a polymer of the gaseous monomer ethylene (C2H4). In the presence of polymerisation catalysts, the double carbon bonds are broken, and polymerisation occurs, resulting in a solid polyethylene resin.
Biobased polymers are plastics produced from biomass rather than from fossil resources.
Bioplastics’ renewable sources and capacity for degradation are positive features. However, the environmental advantages of biobased polymers are somewhat countered by the inability of our existing refuse-handling infrastructure to cater for these new waste materials. Biobased polymers are designed to decompose aerobically, under industrial composting conditions, but in an ambient environment, they can take a very long time to biodegrade. Just like their petrobased counterparts, biobased polymers could still be hanging around in landfill sites and the Earth’s oceans a hundred years from now.
A 2011 Government initiative to apply a century-old sewage-treatment process to food waste management has effected a major change in the way biological waste is decomposed. Anaerobic digestion (AD) is the bacterial breakdown of organic matter in the absence of oxygen. One of the by-products of AD is a biofuel – a sustainable alternative to fossil fuel.
Because biobased polymers can’t be decomposed without oxygen, these materials must be separated from food waste by refuse services. And in the main, they’re unsuitable for recycling. So, our fantastic, sustainable, environmentally friendly bioplastics are very likely destined for a landfill grave.
Today, in 2021, facilities for industrial aerobic composting are not available. It seems reasonable to suppose that this kind of waste management will be introduced at some point. But it would be naïve of us to expect vast, complex, and expensive industrial processes to keep up with fast-changing trends.
Let’s have a look at three alternatives to plastic cling film.
Cellophane, invented by Jacques Brandenberger (1872-1954) and patented in 1912, is made from wood, cotton, or hemp cellulose. This biobased polymer will biodegrade within months, and under certain conditions, within days. There are, however, other environmental issues associated with cellophane, such as the energy consumed, and gases emitted, during production.
A disadvantage of cellophane wrap is its inability to cling to itself and to other surfaces. It’s not quite as convenient as cling film. However, single-use cellophane food bags (‘cello bags’) are widely available.
Please note that ‘cello’ is pronounced sello and shouldn’t be confused with the musical instrument. If you’re looking for a cello case, you probably won’t find one in Tesco.
The word ‘cellophane’ is a portmanteau of cellulose and diaphane (French, ‘translucent’).
Aluminium foil is a good substitute for cling film. Having made its debut appearance early in the 20th century, aluminium foil soon took the place of tin foil, which had been around since before the turn of the century. Malleable and versatile, aluminium foil acts as a barrier to moisture, light, bacteria, air, odours, and flavours – and, unlike its predecessor, does not contaminate food with its own metallic taste and smell.
Not only is aluminium foil a useful household product – it’s also infinitely recyclable. Like steel, aluminium can be recycled over and over, never losing the properties of the fresh product. Recycling scrap aluminium consumes just 5% of the energy required in the production of new aluminium from raw ore.
Beeswax wraps are made from cotton or linen, infused with jojoba oil (from the seed of Simmondsia chinensis), coconut oil (from the fruit of Cocos nucifera), rosin (resin from trees of the genus Pinus), and beeswax (cera alba, made by honeybees of the genus Apis).
Softened by warmth from your hands, these tacky wraps can be moulded around a piece of food or over a dish. Beeswax wraps are designed to be washed in cool, soapy water between uses, and when they become worn and cracked, they can be revitalised by exposure to gentle heat – under hot sun or a moderate grill – which softens the wax content, allowing it to reset evenly.
At the end of their useful life, which could be a year or more, beeswax wraps can be composted with other organic material.