Scientists have found why dirty laundry stinks

Researchers at the University of Northumbria have discovered which chemical compounds are responsible for the unpleasant odor that worn clothing has. They found six volatile organic substances produced by bacteria living on our skin. The study should help in finding the most effective and least harmful to the environment means for washing clothes.

Human sweat does not have a pronounced odor - the waste products of bacteria living on human skin smell unpleasantly. They process the organic matter released from the sweat, skin particles and the secret of glands, and in turn release other substances.
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In the experiment, the subjects wore socks and T-shirts, which the researchers then studied. They were sniffed, put odor odds on a scale from 1 to 10, took samples, then washed and sampled again.

Collected samples were studied using a gas chromatograph and a process for analyzing volatile substances known as SHS-MCC-GC-IMS . The researchers analyzed the composition and smell of the obtained chemical compounds, compared them with estimates of stinkiness and chose those that smelled most unpleasant.

A total of six compounds were determined - butyric acid, dimethane disulfide, dimethane trisulfide, 2-heptanone, 2-nonanone and 2-octanone. As the scientists note, butyric acid has an unpleasant, bitter-fat smell, sulfur and methane compounds smell like onions, and the three ketones resemble grass, banana peel and apples by smell.

Interestingly, although the concentration of these substances on the washed things has decreased, it did not become zero. Scientists hope to pick up such substances for washing, which effectively eliminate the listed substances from clothes, causing minimal damage to the environment .