As company spokeswoman Miyuki Nakayama claimed Tuesday, plasma-cluster ions also proved effective against 26 other kinds of harmful airborne substances, including bacteria, mold fungi, viruses and allergens.

``The device is the first in the world to have been proven effective against the avian virus,'' she said.

Plasma-cluster ion technology, developed in 2000, is an air-purification technology that disables airborne micro-organisms by releasing positive and negative ions into the air.

The Osaka-based company began five months of experiments, testing the technology on bird flu in collaboration with British research institute Retroscreen Virology in January before announcing the results.

The virus was sprayed into a one-cubic-meter box, then plasma-cluster ions were turned on. Samples were then taken at 10-minute intervals and injected into cell cultures. The experiment showed that 99 percent of the H5N1 virus was eliminated.

According to a company report, ``four days after injection, the cells injected with the virus that had not been exposed to plasma-cluster ions were deformed and damaged [by the virus].

``In contrast, cells injected with the virus that had been exposed to plasma-cluster ions retained their normal condition with almost no change in evidence.''

The technology can be adapted for use with air-conditioners, dehumidifiers and air-purifiers in home, office and industrial settings.

The H5N1 virus has been identified as a strain of flu that could prove devastating if it genetically mutates and develops the capacity to be transmitted from human to human.

``People's concern about bird flu is still high, especially in Asia,'' Nakayama noted. ``We hope our product can help eliminate the virus.''