US scientists have developed a self-cleaning cotton fabric that can kill bacteria and break down toxic chemicals such as pesticide residues when exposed to light - opening up new applications in biological and chemical protective clothing.

Researchers at the University of California, Davis have found a way to incorporate a compound known as 2-anthraquinone carboxylic acid, or 2-AQC, into cotton fabrics.

The chemical bonds strongly to the cellulose in cotton, making it difficult to wash off, unlike current self-cleaning agents.

Also, unlike some other experimental agents that have been applied to cotton, it does not affect the properties of the fabric.

When exposed to light, 2-AQC produces so-called reactive oxygen species, such as hydroxyl radicals and hydrogen peroxide, which kill bacteria and break down organic compounds such as pesticides and other toxins. Although 2-AQC is more expensive than other compounds, the researchers say that cheaper equivalents are available.

"The new fabric has potential applications in biological and chemical protective clothing for health care, food processing and farmworkers, as well as military personnel," said Ning Liu, who conducted the work as a doctoral student in the UC Davis division of textiles of clothing.