Ever wondered what happens to your disposable fashion once you’ve disposed of it? Who gets that Topshop T-shirt you posted in the Oxfam clothing bank, or the dress that was always too small for you that you donated to the charity shop?

“Disposability has caused an explosion of problems,” says Dr Lucy Norris, the co-curator of a new exhibition at the Horniman Museum in south London, which traces the odyssey of clothes dumped in Oxfam clothing banks and charity shops. “Clothing is now given in such huge quantities to British charities that they can’t sell it all in the shops. The volume is increasing, while the quality is decreasing.”

For charities to get a return on our tat, most of it is exported. But if you had visions of your old treasures being parachuted into Burma as aid, think again. Charities don’t give clothes away, they sell them. “It takes too long to ship things to disaster areas, and to air-freight them is too expensive,” says Rob McNeil of Oxfam.

Instead, the clothes end up in eastern Europe, Africa and Asia, where they are either sold whole or organised into great colour- coded mounds, as in Panipat, north India, then shredded, pulped and respun into what is known as “shoddy” yarn (recycled wool) and made into cheap blankets.

Before it gets to India, though, the charity shops nab the best. Wardrobe turnaround is so fast nowadays that donations are often just a season old and, increasingly, unworn. Anything that isn’t sold within two weeks is sent to Wastesaver, Oxfam’s clothes-sorting depot in Huddersfield. Here, clothing experts cherry-pick the best to sell on eBay. Specialist stuff — wedding gowns, fancy dress, wellies — is sold via Oxfam’s mobile shop, which tours festivals (this year, Glastonbury, T in the Park, Womad, V Festival and more). Many charities are reworking unsaleable stock into seasonal trends to sell in their shops: Oxfam is working with London College of Fashion students, Cancer Research UK with the ecofashion collective Revamp, and Traid with its in-house label Traidremade.

The problem is that much of what is donated is synthetic, which is the most difficult to recycle; cotton is also expensive to reuse. The easiest textile to recycle is wool, but the demise of knitwear over the past 15 years has seen the “shoddy” industry suffer. And while donation bins are being stuffed with synthetics, charity shops are struggling to stay competitive with the likes of £3 jeans.

Now that our castoffs are being shipped halfway around the world, what about the environment? Do the benefits of recycling outweigh the carbon cost of shipping? Oxfam hasn’t assessed that: the environmental benefit is only part of the story — cash is the rest. And it’s a difficult area. Second-hand clothing exports can damage the local garment trade — from 1985 to 1992, 51 out of 72 Zambian clothing firms closed, partly due to foreign competition. “If we sent stuff to where there is already a second-hand clothing market, it could undercut that industry,” says McNeil.

There are further complications. “From an environmental point of view, we need to be recycling more,” says Alan Wheeler of the Textile Recycling Association. Sales of new clothing in the UK have risen by 60% in the past decade — we now consume 2m tonnes of clothing and textiles a year. Of that, 1.1m tonnes go straight in the bin, while just 300,000 tonnes are recycled (the rest is probably still sitting in our wardrobes). “But double the amount would create a real economic problem with regards to the difficult grades.”

What to do? What to recycle, and what to chuck? Perhaps we should cut up our credit cards. No, our economy needs us. Or stop buying synthetics? But synthetics are more energy-efficient on the laundry front than natural fibres. “There’s no straight answer,” says Wheeler. He suggests buying more second-hand clothing and investing in fewer, more durable clothes. Oh, and please, don’t bin the remains of your Friday-night kebab in the clothing bank either.

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