Ironing out underarm odor. (Hygiene).

Many bacteria, including the skin-dwelling ones responsible for stinky armpits, require iron for their growth. Andrew Landa of Unilever Research and Development Laboratory in Port Sunlight, United Kingdom, and his colleagues plan to exploit that reliance by including iron-sequestering additives in their company's personal-hygiene products. The team added to deodorants a chemical called butylated hydroxytoluene, which releases iron bound in sweat, and diethylenetriamine pentaacetic acid. This agent mops up free iron, keeping it away from microbes. Human underarms coated with the reformulated deodorant had many fewer bacteria than those receiving a conventional deodorant did. More importantly, the armpits protected by the experimental deodorant smelled less strong, the team reports.--J.T.