fast fashion leaves a pollution footprint, with each step of the clothing life cycle generating potential environmental and occupational hazards. For example, polyester, the most widely used manufactured fiber, is made from petroleum... The manufacture of polyester and other synthetic fabrics is an energy-intensive process requiring large amounts of crude oil and releasing emissions including volatile organic compounds, particulate matter, and acid gases such as hydrogen chloride... The EPA, under the Resource Conservation and Recovery Act, considers many textile manufacturing facilities to be hazardous waste generators.
I discussed eco-fashion a little with my friend the other night who is a professor of business. His argument was that as long as the clothing is bio-degradable, it shouldn't matter if it's fast-fashion and if we consume a lot of it. As long as it doesn't leave a big impact after it's been used. I haven't found data yet on how long it takes clothing to deteriorate in landfills (OK I haven't exactly looked for it yet), but this EHP article made an interesting point about where clothing goes after we donate it to charities:
Only about one-fifth of the clothing donated to charities is directly used or sold in their thrift shops... charities find another way to fund their programs using the clothing and other textiles that can’t be sold at their thrift shops: they sell it to textile recyclers at 5–7 cents per pound... According to figures from [textile manufactures] about 30% of these textiles are turned into absorbent wiping rags for industrial uses, and another 25–30% are recycled into fiber for use as stuffing for upholstery, insulation, and the manufacture of paper products... About 45% of these textiles continue their life as clothing, just not domestically... Used clothing is sold in more than 100 countries.
Although it looks like a lot of used clothing is being re-purposed, I still disagree with my friend's opinion on fast-fashion not being "waste" after it completes it's life cycle (sorry Paulo). Even if it does get re-worn, or turned into a rag, I think it will eventually end up in a landfill. Also, separate from that we can't forget about the strain on resources caused during manufacturing.
Hmmm more research is definitely needed...