Again.

The market for antimicrobial doorknobs, hospital fixtures and other products that kill germs on contact may be about to take on a coppery sheen.

The Copper Development Association, a trade group for copper companies, said Tuesday that federal regulators had approved its application to market a group of copper alloys, including brass and bronze, as capable of killing bacteria and microbes effectively enough to protect human health. . .

Researchers who worked on the concept expect hospitals and other public institutions to be the initial market for the product, based on the approvals gained by the trade group. The tests showed 99.9 percent kill rates within two hours against the leading antibiotic-resistant bacteria now plaguing hospitals, said Harold T. Michels, senior vice president for technology and technical services at the trade group.

“This is very, very solid data,” said Mr. Michels, who said that the tests involved more than 3,000 samples and included a requirement to reinfect a surface eight times in a single 24-hour period to prove the results were durable. Mr. Michels said clinical trials were under way to test how copper bed rails, arm rests and other hospital fixtures can reduce the numbers of bacteria in hospitals.

It seems that they would be good in the kitchen and loo too.