Are your pants bad for the planet?

Pants, briefs, knickers, underwear: whatever you call them, we wear them every day and, sooner or later, they wear out.

There's not much of a second-hand market in undies (thankfully!) - or socks, bras, and other assorted lingerie, for that matter - so we usually buy them brand new. But once they turn an unappealing shade of grey or the elastic stretches out, they go straight into the bin.

So just how polluting are our pants, and is there a way to buy better bloomers?

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What's the problem with pants?

In 2020, Statista reported that the UK underwear market was worth about £3.4bn, and forecast to reach £4.3bn by 2025.

On a global scale, lingerie is expected to hit $250bn by 2022, according to Allied Market Research. That's an awful lot of pants.

Unfortunately, underwear manufacturing works in much the same way as the rest of the clothes industry. Some luxury brands design and make their own underwear, but most retailers rely on imports made quickly and cheaply in overseas factories.

Find out more: our recent investigation into fast fashion and greenwashing

The same problems that arise from fast fashion also apply to our undies. Unsustainable fossil-fuel-based fabrics, polluting chemical dyes, excessive water use and ever-increasing carbon emissions all plague the industry, together with human rights issues such as forced labour and unsafe working conditions.

Don't worry - we're certainly not going to suggest you go commando. But we have found some helpful ways for you to up your underwear game:

1. Buy less and buy better

No matter what you're buying, a sustainable choice is usually to buy less of it at a better quality. Longer-lasting items are generally less harmful to the planet and give better value for money in the long run.

So, if you're able to, invest in high-quality underwear that is comfortable and well-made, instead of opting for a 10-pack of cheap briefs.

Find more top tips: our latest sustainability advice

2. Choose sustainable fabrics...

The most eco-friendly fabrics have low environmental impacts during their production. Ideally, that means they'd have low water and energy use, no harmful chemical use, and be biodegradable when you're finished with them. Some are also made from waste or renewable resources.

Unfortunately, there's no perfect choice. However, organic cotton, linen, hemp, and ramie (a fibre similar to linen, made from nettles) are good plant-based choices, while lyocell and sustainable viscose are good semi-synthetic options (plant-based but with additional processing).

Recycled fabrics made from waste materials can also be a good option, such as recycled polyester, nylon, cotton, and wool. Petroleum-based fabrics, such as polyester and nylon, aren't biodegradable, however, and can break down into microplastic fragments.

If you're really going for luxury, then silk is both renewable and biodegradable. However, conventional silk uses chemicals for processing, so organic silk is a better option. Conventional silk farming also kills the silkworm, so look out for peace silk, which allows the moth to escape before the cocoon is processed.

3. ...and avoid unsustainable ones

The manufacture of synthetic, petroleum-based fabrics such as acrylic, nylon, and polyester harms the environment, releases chemical pollutants, and requires large quantities of water for processing and dyeing.

They are also among the least biodegradable fabrics. When they break down, they form microplastics, which pollute the planet and are a danger to humans and wildlife.

Find out:how to stop plastics from your clothes polluting the planet

Other petroleum-based fabrics such as elastane, also known as Lycra or spandex, are often mixed with other fibres to give added stretch. Mixed or blended fabrics are very difficult to recycle, as the different fibres can't be separated.

Some plant-based fabrics are less sustainable than they appear. Bamboo, for example, grows very quickly and easily, and doesn't need pesticide or fertilisers. However, it's processed with strong chemical solvents that are potentially harmful to the health of manufacturing workers, and for the environment when chemicals are released into watercourses.

Standard, or conventional, cotton also comes with problems. Cotton farming represents 10% of the pesticides and 25% of the insecticides used globally and uses up to 20,000 litres of water to produce 1kg of cotton. Organic, recycled, Fairtrade or cotton produced under the Better Cotton Initiative (BCI) scheme are better choices.

Our recent investigation into jeans explains how to look out for more sustainable cotton.

4. Look after your lingerie

We tend to wash underwear more frequently than other clothes, so it pays to treat it right. Check the care label and follow the instructions.

Delicate lingerie may need handwashing. Don't wring it out too forcefully to avoid stretching, and dry flat.

For machine-washable underwear, use the recommended settings. To prevent whites turning grey, wash them separately from coloured clothes.

Put delicate items and bras inside a mesh bag for protection, and use a mild detergent. Avoid fabric softener and tumble drying, which can both affect the elasticity of clothes.

Use our expert laundry guide to keep your lingerie looking good for longer.

5. Donate old underwear

Although you're unlikely to see much pre-loved underwear in your local charity shop, there are ways to donate lingerie.

• Marks and Spencer encourages customers to drop bras (of any brand) into its in-store 'Schwop' recycling boxes or at an Oxfam store. The bras are then either sold in Oxfam stores or processed at its recycling facility. From there they are sent to Oxfam's social enterprise project in Senegal, Frip Ethique - 'Frip' is the local term for second-hand clothing, while 'Ethique' means ethical. The bras are sold on to local traders who sell them in their local communities.
• Smalls for All is a Scottish charity that collects new and lightly worn bras, plus new, unworn pants, to give to adults and children in need both in Africa and the UK.
• The charity Against Breast Cancer takes unwanted bras through a network of bra banks and raises vital funds for breast cancer research.
• Swedish Stockings will recycle old tights to make fibreglass tanks. Send three or more pairs of synthetic tights, and the company will give you a 10% discount.
• Sock Shop's #socksforacause campaign encourages people to donate socks to homeless charities, who report that socks are one of the most needed but least donated items.

Most charity shops are only able to sell underwear that is unworn and still has the labels on. Worn items can still benefit the charity by being sold as 'rag' - as can any unsellable clothing. Many large charities will accept rag but it's best to check first, and donate them specifically as rags rather than mixing them up with sellable clothes.

6. Upcycle underwear to use around the house

Yes, you really can repurpose old underwear! We've found some creative uses for your cast-offs.

1. Turn old undies into rags or cleaning cloths. They're good for washing the car or wiping down surfaces around the home. Cut off any buttons or zips first, and cut out elastic - which gardeners can use as plant supports in place of plastic ties.
2. Cut into strips or squares and use to stuff (or restuff) cushions, soft toys or pet toys.
3. Make a draught excluder by stuffing old tights or long socks with old knickers.
4. If you're the crafty type, there are plenty of sewing projects that repurpose old lingerie. There are online tutorials for hair ties or scrunchies, lavender sachets, cloth bags and, if you have a seriously large stash of undies, patchwork quilts.

Whatever you do, don't bin it

There's no need for your undies to end up in landfill. Check with your local council whether you can put textiles in your kerbside recycling. If so, underwear can go in there too.

All clothing, even bras, pants and socks, can be put into textile recycling banks. Recycle Now has an online recycling locator to find your nearest options.

You can compost 100%-cotton items. Other natural materials, such as linen, hemp, bamboo and silk, are also biodegradable; however, check that no harmful dyes or other treatments have been used. Remove any non-compostable elastic or trim and chop fabric into small pieces before you put it in the compost bin.