The elegance, the drape, the style… It seems impossible not to fall in love with silk, right? But would we still be in love if we knew its true cost?
Silk is one of the oldest and most luxurious fabrics in the world. However, its production appears to have a larger environmental impact than other natural fabrics. Indeed, according to the Sustainable Apparel Coalition’s Higg Index, it has a worse environmental impact than synthetic fabrics.
Let’s find out how sustainable silk really is!
The origin of silk
The origins of silk date back to ancient China where it was reserved for emperors. The oldest evidence was found buried in 8,500-year-old tombs[1]. From there, this fiber became a major element of the Chinese economy, so much so that it was one of the country’s most valued commodities. Over the years, its use became more widespread as it began to be used for musical instruments, fishing lines, bonds of all kinds, and even rag paper.[2]
Qualities
Silk is produced by silkworms that form the cocoon within which the larvae develop. Each of these little animals can produce over 900 meters (3,000 ft) long of 0.025 mm thick thread.[3] Impressive!
Silk is one of the strongest natural fibers in the world and is characterized by its beautiful drape and versatility. This luxurious fiber has good moisture absorption, stays cool in hot weather and warm in cool weather.
However, since this material loses a significant amount of its strength when wet, it needs to be washed delicately to ensure longevity. Another drawback is that it wrinkles easily and is not very stretchy.
The ethical dilemma: production process
For centuries, the production process of silk remained a Chinese well-guarded secret. Today that secret has spread and has presented us with a major ethical dilemma.
Sericulture, or silk-making, begins with cultivating silkworms (Bombyx mori). Silk moths are bred and lay eggs on specially prepared paper. When the eggs hatch, the caterpillars are fed mulberry leaves. After just over a month the caterpillars begin to spin their cocoon within which the silkworms metamorphosize into a moth. If allowed to continue naturally, the process continues with the secretion of a fluid by the moth that dissolves one end of the cocoon allowing them to emerge.
When it comes to silk production, the process takes a different course. Given that the mentioned secretion ruins the filament fiber by cutting it short, most silkworms get killed inside the cocoon before metamorphosis is complete (generally with steam). For purposes of breeding, some silkworms are allowed to metamorphosize. Then the cocoons are sorted by size, fiber quality, and defects, and the filaments are brushed to find their end.[4]
Once the filaments are brushed several of them are gathered to form a yarn and are twisted onto a reel in a process called “reeling”. After this, the “degumming” begins and the remaining sericin is removed from the silk. This causes the silk to weaken and to lose about 20% of its weight.[5]
The next step is “weighting”. Since silk is sold by weight, weighting is a practice that is peculiar to sericulture. It involves the application of metallic salts to add body, luster, and physical weight to silk fabric. Finally, the “dying” process begins, which tends to be chemical, water, and energy-intensive.[6]
How sustainable is silk?
Silk is often referred to as sustainable because it is biodegradable (when untreated) and uses fewer chemicals than many other fibers. Yet, things get a bit murkier when we take a look at the risks related to animal rights, water, and energy consumption, and their impact on workers and their communities.
Animal Rights
Conventional silk is not vegan. As explained before, most silkworms are killed in their cocoons before metamorphosis. Luckily, there are some more animal-friendly alternatives (though less luxurious): “Peace silk” allows moths to emerge from their cocoons, and “wild silk” is found in open forests and is harvested after the moths leave the cocoons.
Pesticides and chemicals
Although significantly less than cotton and other natural fibers, the growing of mulberry trees to produce conventional silk generally require chemical pesticides and fertilizers. One mature mulberry tree can produce enough foliage for 100 silkworms,[7] and it takes about 2,500 silkworms’ worth of filament to produce about a pound of silk fabric.[8] Do the math on how many trees are needed…
Toxic chemicals are generally used during the production process. Most conventional silk uses chemical dyes and finishes which can pollute local water, hinder the fabric’s biodegradability, and contribute to the toxic impact of the fabric.[9] Also, sometimes untreated wastewater is dumped directly into groundwater, which is hazardous to the ecosystem and nearby communities.
Chemicals are also present once silk garments reach the hands of consumers. Many silk garments require dry cleaning, which uses solvents that can harm the environment.
Water and energy usage
From the growing of mulberry trees to the transport of materials, silk production uses high amounts of water and energy.
Water-wise, the mulberry tree is a thirsty one and can stress freshwater supplies if the trees are planted in places where water is scarce.[10] Regarding energy usage, this is where silk causes the most environmental damage. Silk farms must be kept at a certain humidity and controlled temperatures. Also, harvesting and drying the cocoons uses both hot water and hot air.[11] Unfortunately, the most energy-intensive part of the process tends to be cooking the cocoons.[12].
Workers
Silk production is labor-intensive but can be an important livelihood for farmers[13], especially in Asian countries such as China and India (the silk industry employs around one million workers in China and 7.9 million workers in India[14]). However, it has been reported that some 350,000 children work in the silk industry.[15] Also, workers are generally exposed to chemicals through breathing and skin contact during production and material processing because proper equipment and safety precautions are rarely used.
Are there any sustainable options?
Yes! For a slightly higher price, customers can access more sustainable silk options, namely:
- Organic Silk – This is an excellent option as long as there are certifications! Look for silk that is certified organic by the Global Organic Textile Standard.
- Peace Silk – This comes from cocoons where moths were allowed to emerge from their cocoons. Unfortunately, the Bombyx mori moth used in most commercial silk production barely survives after emerging from its cocoon.[16] Over the time these moths have been domesticated, and so they aren’t able to survive long beyond cocoon stage (they have lost their ability to fly, see, camouflage, and fear predators). This makes us wonder how ethical is this silk…
- Wild Silk – This is made from cocoons found in open forests. It has shorter fibers and, given that the caterpillars eat a variety of plants and leaves, the resulting fiber is less consistent than the conventional one.[17]
- Vegan Silk – We know that silk garments are irresistible, even to vegans…so the industry has managed to create plant-based option. Stems of the lotus flower can be made into silk-like fabric, although it takes a huge volume of the stems to make a small length of the fabric.[18]
Final Verdict
It pains us to say it but, as much as we love it, conventional silk doesn’t have The Pomelade approval. The excessive consumption of resources and animal abuse cloud any goodness it may have.
Our recommendations? Try to choose one of the sustainable options, buy secondhand, or look for silk that is certified organic by the Global Organic Textile Standard.
What do you think about silk? Do you agree with our final comments? Let is know in the comments below!
