Environmentalism is very much the zeitgeist today; whether in terms of the climate protests that have struck the globe’s cities in the past months or in growing consumer trends, being environmentally friendly has never been so high on the global agenda. Sustainability is part of this, and the desire to protect the environment by only taking what we can afford to from it has driven many to question how eco-friendly their purchases really are.
Producing frames for spectacles and sunglasses can be both unsustainable and incredibly wasteful, especially where cheap plastic sunglasses are concerned. But what are the alternatives to plastic, and what are frame manufacturers doing to respond to the growing call for sustainable materials in eyewear?
Cellulose Acetate
As one of the most prominent materials used for making spectacle frames, cellulose acetate can often slip under the radar, being thought of as just another sort of plastic. While it does qualify as a plastic cellulose acetate is a natural material manufactured by purifying the cellulose found in cotton linters and wood pulp. The material was first used for spectacle frames in the 1940s and ever since has been utilised for its high flexibility, low weight and hypoallergenic properties. However, just because a material is derived from natural, renewable materials such as cotton it does not automatically qualify as sustainably sourced.
Tree pulp and cotton linters are two materials which have the capacity to be very harmful to the environment when grown and harvested. Cotton is the most prevalent non-food crop globally, and its production employs almost 7% of all labour in developing countries. The crop is incredibly water intensive, with more than half of global cotton production taking place in areas under high or extreme water stress. While 30% of global cotton production comes from rain-fed farming, the rest relies on irrigation which can have dramatic consequences; the Aral Sea, formerly the fourth largest lake in the world, has shrunk to just 10% of its original size since the 1960s when Soviet irrigation projects began to divert its water towards cotton production in Uzbekistan. Tree pulp too, can degrade the environment through deforestation and its manufacture, which sometimes involves the use of chemicals to process wood chips into the finished product. Most pulp mills do make use of sustainable forest management techniques in harvesting trees, however.
Producing acetate of suitable quality for frames also requires the addition of a plasticiser to the material, which improve acetate’s flexibility and durability. The industry standard plasticiser is diethyl phthalate (DEP), which releases the harmful chemical phthalic acid when acetate biodegrades. The premier manufacturer of acetate in Europe, Mazzucchelli 1849, uses DEP for its standard formulation. However, other natural and non-toxic plasticisers are seeing increasing usage, with Mazzucchelli opting for a vegetable derived plasticiser in its eco-friendly M49 formulation.
Bio-acetate
The above does not write off cellulose acetate as an eco-friendly frame material. Its raw materials, cotton linters and wood pulp, can be harvested sustainably and increasingly are. That it is derived from natural materials means that, unlike plastic, acetate will bio-degrade in under a year if submerged in water or compost. In bio-based acetate, which contains naturally derived plasticisers, this biodegradation is an entirely toxin free process allowing for the natural materials used to return to the earth cleanly and without harming the environment.
Acetate can be produced sustainably
Bio-based acetate has received high-profile endorsement and attention recently. Earlier in 2019 the luxury brand Stella McCartney released its bio-acetate eyewear campaign championing the sustainable credentials of the material. Mazzucchelli’s M49 product, which the company markets as 100% eco-friendly, biodegradable and recyclable is also popular with frame manufacturers. Robbert Wefers-Bettink, one of the founders of sustainable sunglasses and spectacles manufacturer Dick Moby, told Optician: ‘We source our acetate at Mazzucchelli, and check all of the material claims from the factories we work with to make sure they act sustainably. Bio-acetate is an oil-free plastic which can bio-degrade in an industrial compost environment. It’s not the perfect sustainable material, but it is the most sustainable material currently on the market without losing any properties that are needed for a pair of high-quality eyewear.’
Recycled
When discussing materials for frames and their sustainability, identifying a perfect solution is impossible; every manufacturing process taxes the environment in some way. Recycling or salvaging otherwise wasted materials can present an effective solution to the problem of manufacturing though, since the process of creating a material has often already taken place. Dick Moby impressively includes environmental impact statistics on its website. For the recycled acetate used in some of their frames, which is swept from the floor of Mazzucchelli’s factory, the impact per frame is 0 litres of water compared to 2.56 litres in new acetate, 0.014kg of CO2 compared to 0.034kg and 0.07mj of energy used compared to 0.89mj. Wefers-Bettink explained that this recycled acetate is composed of the waste from non-bio acetate, since there is not enough waste from producing bio-acetate to collect and use. Since this material would otherwise be wasted though, this non-bio acetate has negligible environmental impact.
While companies like Dick Moby utilise material that would otherwise be wasted, other manufacturers make use of already wasted resources. Sea2See designs and produces optical frames and sunglasses entirely made from recycled marine plastic waste which is collected via a partnership with thousands of fishermen. The company’s trucks collect around a tonne of waste per day from ports and then transform it into an environmentally certified recycled polymer used to produce 100% of the company’s glasses. The plastic Sea2See use is oil-based but if their frames are discarded in the sea the environmental impact on ocean contamination is non-existent, since the salvage process cleans the oceans.
Other companies, such as Retrospecced, eschew production entirely for a simpler solution. Retrospecced purchase select frames which have been donated to optical charity Vision Aid Overseas and refurbish them for sale, removing the need for anything but rudimentary procedures such as cleaning and reglazing. This model of providing frames to a consumer does not harm the environment because the frames already exist, and customers have the added benefit of knowing they are contributing indirectly to a good cause in the form of Vision Aid Overseas.
Wood and bamboo
Acetate, bio-acetate and plastic frames can all be sustainable if sustainability is made a focus of their production. Wood and bamboo, however, have more natural sustainable properties than plastics and are seeing increasing use as eco-friendly frame materials. For starters, trees sequester CO2 from the atmosphere and store it as wood while simultaneously producing clean oxygen. On average, one acre of new forest can sequester about 2.5 tonnes of carbon annually, and this is only released back into the atmosphere if the wood is burnt. Bamboo, which is actually a type of grass, also produces oxygen and sequesters carbon during growth and can be harvested in one to five years depending on the species.
Bamboo is a sustainable frame material option
Unsustainable forestry can present problems for wood and bamboo’s sustainable qualities. The recent Amazon fires which captured global attention have been linked to illegal logging and deforestation; while wood may be a sustainable material, its harvest can often do more harm than good to the environment if not sustainably managed. Companies which utilise wood and bamboo in their frames tend to have environmental motivations however, and make sure to source their materials from sustainable sources. Founder of sustainable eyewear brand Bird Sunglasses, Ed Bird, told Optician: ‘Wood and bamboo are extremely sustainable when sourced sustainably.
Sustainability and ethical considerations are the core of our business and these considerations apply to the materials we use in production. We source our wood from a reputable company that carries FSC certifications and work closely with our suppliers to confirm their providers and supply chains as much as possible.’
JP Janvier, co-founder of bamboo focused eyewear brand Fresh For Pandas echoed these sentiments: ‘Bamboo is only really commercially grown in China, which is where we source ours from. The wood is from FSC certified stock, which we have independently and directly verified with our suppliers. When you compare the manufacture of wood eyeglasses to plastic or metal, there’s very little comparison. The industrial byproduct of our wood eyeglasses is quite literally sawdust – significantly less damaging than acetate production or the production of the frames themselves.’
Wood and bamboo do seem to edge out acetate in terms of their sustainable qualities, but in assessing eco-friendly eyewear the quality of the frames must also be considered. Wood does not necessarily provide the durability or flexibility of acetate, especially in its untreated form. Bird commented: ‘It’s a beautiful material to work with, but wood’s not as robust as plastic or acetate. We try to create the right mix, which is why in our Strata range we incorporate layers of aluminium into the core to strengthen the frames.’ Janvier added: ‘There’s no question that bamboo’s a viable material for frames, but it has its downsides. Bamboo isn’t as strong as acetate for intricate frames so users need to take extra care to use a hard case. Our frames are treated with a plant-based finish to preserve the wood and provide water resistance, but no artificial chemicals are used in this process.’
Other natural materials
Wood and bamboo may be sustainable materials, but they require some processing to take on the qualities usually looked for in frames. Other natural materials require less processing but also run into problems. Tortoiseshell is a word seen often in relation to frames and describes a dappled colour mix, but its origins lie in the past use of Hawksbill sea turtle shell to make frames. These animals are officially endangered today and use of their shells to make products is illegal. The shell of a turtle is an organic material composed of keratin, a fibrous structural protein found in many animals. The horns of mammals are also composed of the material, albeit a less hard version than that found in reptiles, and some luxury brands make use of water buffalo horn to produce elegant frames.
Asian water buffalo horn is a sustainable frame material option
German brand Hoffman Natural Eyewear is known for its use of horn and values the animal product for its sustainable qualities alongside its heritage as one of the oldest frame materials in the world. Like most horn used in frames Hoffman gets this material from the Asian water buffalo, but only collect the horns upon the natural demise of the animal. As an otherwise unused by-product of an animal’s death, horn is eminently sustainable. Even the by-product of turning the horns into frames, horn shavings, are then used to make natural fertiliser. Horn frames are expensive however, and require more care than other materials to ensure they are not scratched or broken.
Experimental frame materials which emphasise sustainability have been explored recently. Hemp Eyewear, which produces frames made mostly from the quintessential eco-friendly material hemp, have recently launched a Kickstarter campaign to fund its handmade frames. Cubitts, the British ‘clicks-and-mortar’ optician, produced its Redux range of experimental frames in August to see whether innovative materials could present viable alternatives to options that already exist. Featuring natural frames made from wool, human hair, corn husks and even potatoes, the experiments are being tested for suitability and may end up appearing in Cubitts’ commercial range.
Verdict
In an era where more and more focus is placed on sustainability, environment-conscious consumers are somewhat spoilt for choice for eco-friendly frame materials. Cost and material properties are absolutely a factor, and those willing to splash more cash will be able to bag themselves frames in luxury materials like horn.
Environmental purists may find problems with any frame material but the majority should be happy with abundant options for style and shape in bio-degradeable materials like bio-acetate and wood, or in recycled plastics. And who knows, maybe soon we will all be wearing frames made from human hair.
