Why synthetic fabrics smell faster

Short answer: Odour forms when bacteria on the skin get moisture and warmth. Synthetic fibres keep moisture on the surface, which is exactly where those bacteria do best. Skin oils also bind to synthetic fibres and stay put, so the smell can return sooner, even after washing.

Where the smell comes from

Sweat is almost odourless when it leaves the skin. The smell only appears when the bacteria that naturally live on the skin get moisture and warmth to work with. The longer moisture stays close to the skin, the better their conditions. So odour in clothing is less about how much you sweat and more about where the moisture ends up.

Moisture on the surface, not in the fibre

Polyester absorbs almost no moisture, so sweat stays between fabric and skin. It is warm and damp there, which is the setting bacteria need. A fabric that draws moisture into the fibre moves it away from the skin instead. See the most popular pieces for women for everyday wear.

Oils bind to synthetic fibres

Skin oils settle into synthetic fibres and stay there, even after a normal wash. The oil holds on to the smell, which is why a top can smell again soon after you put it on, even though it came out of the machine clean. It is most noticeable in sportswear. See our most popular pieces for other materials.

Why regenerated fibres last longer

Bamboo viscose draws moisture into the fibre, away from the skin, so odour appears later. The skin stays drier and the bacteria have poorer conditions. That does not mean the clothing never smells, but it can usually be worn longer before it does. Natural fibres such as cotton behave in a similar way, since they also absorb moisture.

Feet are a special case

Feet sweat, and in closed shoes the moisture struggles to escape. That makes socks one of the places where material matters most for odour. A sock that absorbs moisture keeps the foot drier through the day. Change socks daily and let shoes dry for a day before wearing them again. See our bamboo socks for women.

Air clothes before the laundry basket

A damp garment scrunched up in the laundry basket gives bacteria time and warmth. Hang it up instead, so it dries before it goes in the basket. This applies especially to sportswear and socks. Avoid leaving wet clothes in a closed bag for hours if you can. The faster they dry, the less they smell.

Wash promptly and properly

Wash clothes soon after wearing, before the smell sets in. Use the amount of detergent given on the pack: too little will not remove the oils, and too much can build up in the fabric. Do not fill the machine to the top, so the water can reach everything. Wash synthetic sportswear inside out.

What to avoid

Fabric softener smells nice but coats the fibres, which can hold on to oils and odour. Scented sprays cover the smell without removing it. Also avoid wearing synthetic sportswear several times between washes. It is better to have a few extra pieces and wash them regularly, so the smell does not build up.

Frequently asked questions

Is it the sweat that smells

No. Sweat is almost odourless. It is the bacteria on the skin that cause the smell when they get moisture and warmth over a longer period.

Why does the smell stay in synthetic clothing

Because skin oils bind to the fibres and are not fully rinsed out in a normal wash at forty degrees, so the smell comes back.

What can you do about it

Wash soon after wearing, let the clothes air before they go in the basket, and use the amount of detergent stated on the pack.