China Electric Manufacturing Corp., Taiwan's No. 1 lamp manufacturer, recently rolled out the island's first tri-wavelength fluorescent lamp coated with titanium dioxide (TiO2)--a photocatalytic material with anti-bacterial functions.

China Electric originally planned to introduce the lamp in October, but the outbreak of SARS (severe acute respiratory syndrome) in Taiwan earlier this year encouraged it to move up the rollout date by several months, says Simon Wu, the company's executive vice president. In May alone, the company sold 100,000 TiO2-coated tubes, as demand for sterilizing devices soared among SARS-spooked consumers.

Wu emphasizes that the new lamp has not been proven to be effective in eliminating the SARS coronavirus. "But we have proven that the lamp can kill staphylococcus aureus and escherichia coli," he says.

According to an anti-microbial test conducted by certification company SGS Taiwan Ltd., China Electric's TiO2 tri-wavelength lamp destroys over 99.99% of the staphylococcus aureus and the escherichia coli contained in separate culture containers after six hours of exposure to the light.

TiO2 is also known for its ability to deodorize, purify and sterilize the air by giving off hydroxyl free radicals (-Ohs) that catch airborne impurities and bacteria.

While other UV-activated TiO2 lamps are sold in Taiwan, China Electric's is unique in that the TiO2 material is coated directly on the surface of the bulb.

Late last year China Electric's nearest rival, Taiwan Fluorescent Lamp (TFL), debuted a UV with a TiO2 adhesive coated on a fiberglass net encircling a circular UV fluorescent lamp. The TFL lamp has a 400-nanometer wavelength, making it unsuitable for general lighting, so the company installs the lamp on electrical fans to disperse the air-purifying -Ohs.

Tricky Process

"Coating the material over a lamp requires sophisticated technique since you have to make sure that the coating is even and durable," says W.S. Ferng, an assistant manager in charge of technology development at China Electric. He says the material tends to wear out easily unless it undergoes a special treatment. His company blends materials into the glue to increase its adhesion and bakes the coating to enhance its retaining power.

China Electric licensed the coating technique from the Center for Environmental Safety & Health Technology Development of the government-backed Industrial Technology Research Institute (ITRI). "We chose to cooperate with the center because it has been developing TiO2 techniques for a while in cooperation with a Japanese company," Ferng notes. Japan's long-term dedication to developing TiO2 techniques and its world- leading applications of the material is well known.

China Electric coats the TiO2 glue on tri- wavelength fluorescent lamps with wavelengths ranging from 380 to 780 nanometers. The special treatment on the lamp lets part of the UV beam penetrate through the lamp wall to activate the photocatalytic material. "We followed Toshiba's example by coating the material on fluorescent lamps," notes Ferng.

At its Taoyuan factory in northern Taiwan, China Electric can turn out 10,000 TiO2 lamps a day. In addition to standard 20-watt and 40- watt tubes, the company has coated TiO2 on globe-shaped compact fluorescent lamps, 3U- shaped compact fluorescent lamps and spiral compact fluorescent lamps.

Not that any of this comes cheap. A 20W TiO2 UV lamp will set you back NT$369 (US$10.5 at US$1:NT$35), or more than six times the cost of China Electric's standard 20W fluorescent lamp. On the other hand the TiO2 lamps are more durable than average lamps. A 20W TiO2 lamp can last up to 7,500 hours, while the 40W version has a 10,000-hour lifespan.

China Electric is marketing the lamp to both corporate and individual users. The lamps are currently available in Taiwan at major retailers, such as B&Q, Onking Chainstore Co., and Tsann Kuen Enterprise Co., as well as directly from China Electric itself.

Corporate Version

For corporate users, the company has developed a lighting fixture with a powerful UV lamp, TiO2 net, TiO2 tri-wavelength lamp and two fans. The fans suck in air through the TiO2 net, which disintegrates and deodorizes organisms in the air. The UV lamp kills remaining bacteria in the air flowing through the net with its 253.7-nanometer wavelength. The TiO2 tri-wavelength lamp also performs a sterilizing function.

The UV lamp is completely concealed inside the fixture. China Electric points out that UV beams with wavelengths ranging from 250 to 260 nanometers are the most effective for killing bacteria. Although tri-wavelength lamps also give off UV beams, the lamps have a special treatment that only permits a safe 1.4% of the UV radiation to penetrate the bulb. The 20W tri-wavelength lamp emits 1,400 lm of brightness, making it an ideal for general lighting purposes.

The complete lighting fixture set is available at around NT$5,000 to NT$6,000 (US$143 to US$171 at US$1:NT$35) per system. Due to the high cost, China Electric has targeted the new product at organizations such as hospitals, schools, government agencies, and public buildings. It donated 40 sets of the lighting fixture to the Taipei Municipal Yang-Ming Hospital and the Taipei Municipal Wan-Fang Hospital during the SARS epidemic.

Asia is China Electric's major market for the lamp as the region was hit the hardest by SARS. Outside Taiwan, most shipments are to Hong Kong, mainland China, Vietnam, Singapore and Thailand.