It is a somewhat well-known fact that fast fashion is quite detrimental to the environment and is fueled by our innate want as humans to often acquire something new and exciting. This industry, like most often do, encourage quite a high level of consumerism and contributes to landfills, a staggering amount of waste. It is said that only around 12-15% of clothes thrown out, are recycled. That aside, there remains an ethical issue rooted within this broader problem; and that is the use of animals to produce certain 'materials.'
Fur
According to Surge Activism, around 1 billion animals are killed annually for their fur. These include minks, foxes, rabbits, chinchillas and even cats and dogs.
To get the fur, workers will pull the animals from their small cages and proceed to skin them alive, often having to beat and bludgeon them before they can achieve their goal.
Cases of Covid-19 were even found among mink. In Denmark, humans passed the virus onto mink, which then mutated, and were passed back to the human handlers. In November the Danish government ordered the culling of 17 million minks at fur farms across the country.
Leather
Probably the most common material on this list, used to make clothes, shoes, bags, wallets, office chairs and many other products. Leather is a bit of an umbrella term, referring to the skin of animals such as cows, sheep, pigs, goats, even kangaroos and ostriches as well as dogs and cats. Leather often isn't labeled, therefore one cannot be sure about which animal it came from. One thing is for certain however, to get leather, animals have to die and this is completely unnecessary and avoidable in these modern times. There are now countless alternatives popping up on the market which are free from cruelty. In the image below you'll notice the number of the cow's ear; he/she is just merely a number to the industry, a commodity to exploit.
Wool
Some claim that sheep need to be sheared while others say that they do not. However, the fact is that factory farmed sheep have been domesticated to produce as much wool as possible, making it essentially mandatory for them to be sheared; and though this process should be usually good for the sheep who are relieved from excess weight, it isn't as simple as that. Because shearers, are paid for the amount of wool they 'produce' and not by the hour, they are encouraged to shear as fast as possible. The result of this is little regard for the welfare of these animals, with mistreatment like kicking and stomping commonly seen, as they attempt to hold down the sheep. They are also often cut in the shearers' haste and sewn back up without any pain relief. When the sheep stops producing as they are sent to slaughter, because they become unprofitable to keep around. This is usually when they are around 5-6 years old, effectively halving their natural lifespan.
Other animal-derived materials include silk where silkworms are boiled or gassed alive to produce the material. It takes upwards of 2500 silkworms just to produce one pound of silk.
Over 840 million duck and geese are used every year for their feathers, with China alone accounting for 80% of it. 'Down,' as the material is called, comes from these birds who are held down and plucked violently, sometimes tearing their skin and sewing it back with a needle and thread. They are then returned to their cages where they will be plucked again, once the feathers grow back in about six weeks. Like sheep and other animals, they will be slaughtered when they have been deemed unprofitable to keep around.
It is clear that these industries are far from animal sanctuaries, and the textiles industry in general is, for lack of a better word, complicated. Consumers are becoming increasingly aware of these practices and demand is thankfully falling, but there's still a ways to go.
Sources:
https://www.peta.org/issues/animals-used-for-clothing/fur/chinese-fur-industry/
https://poultrykeeper.com/blog/duck-goose-down-production/