Are LED lights safe? Experts were defeated by this question at an international lighting semiconductor technology application forum on Wednesday. For Shanghai Illuminating Engineering Society’s President Yu Anqi answering this question is just as difficult as answering whether the sun is safe. The sun is generally safe, but staring at the sun for long periods can result in eye burns. In the same way, LED lights are not any more dangerous than traditional lamps if the purchased lamp is certified and used properly, said Yu.

Chips in the widely used white-light LED for interior lighting emit blue light before triggering the phosphor coating to radiate white light. A previous experiment proved blue light can be damaging to the retina, but can it be concluded from these two factors that LED lights can harm the eye? “Of course not,” said Sun Xinghuai, President, The Five Sense Organs Hospital of Fudan University Shanghai. “LED lights are not the only ones that contain blue and white light, cellphones and computer monitors also incorporate blue light. Our hospital has never encountered a case where a person’s eyes were injured because of LED lights.”

Determining whether blue light can damage the eyes retina is in fact highly important to the medical community, and many experiments have been conducted as a result. It is believed macula degeneration, a common eye disease that occurs in middle to old aged people, is caused by over exposure of blue light; but the amount required to trigger the disease remains unknown.

To judge whether LED lights are safe, it might be worthwhile to see if it is any more dangerous than traditional lights. Traditional fluorescent light tubes use low pressure mercury and inert gas to illuminate, giving off ultraviolet (UV) rays during the course of discharge, said Yu. Perhaps we should be more concerned about the potential harms that UV rays bring upon the human body. However, by applying an even phosphor coating, UV ray leakage can be contained to the point that it is barely detectable by equipments. Applying the same logic, as long as the LED light spectrum and surface brightness is controlled within a certain range, it should be a very safe light source.

Yu is often asked about LED safety in the last two years, as LED lamps quickly entered the Chinese market during this period. As 10 percent of China’s interior lighting are currently replaced by LED lights, people are increasingly paying attention to LED safety, said Yang Weiqiao, Deputy Director, Shanghai LED Engineering and Technology Association.

Another worry is blue light’s high color temperature can affect the human brain’s secretion of melatonin, and long periods of exposure to high color temperature can induce insomnia. The effects of blue light on circadian rhythm varies among individuals, and is difficult to spot in the short term, said Yu. If blue light LEDs causes sleeping issues, switching to yellow light LED lamps can greatly improve the situation.

The issue is not LED blue light, but the lack of stringent standards, Yu pointed out. In 2006, the International Illumination Commission (CIE) released an international standard, “Photobiological Safety of Lamps and Lamp Systems,” but due to limited knowledge on the issue, the standard was listed as a recommendation. In contrast, almost all international standards regarding human safety are mandatory. “The application of the standard is clearly erroneous,” said Yu. As people’s awareness of light safety increased, related standards are now the norm, for instance mandatory standards are imposed on lights exported to Europe, however, these standards are not mandatory in the domestic market.

Internationally, the strength of LED blue light sources is classified into four categories ranging from type 0 to type 3. The human eye can only view blue lights with a classification below type 1, people cannot stare at type 2 lights for long periods, while type 3 is unsuitable for lighting. According to sources, a national photobiological safety standard will be implemented next year in China and made mandatory. Lighting products sold will be labeled as type 0 or type 1. Lamps with  light sources greater than type 2 will be stamped with the reminder “do not remove lampshade when cleaning” or with warnings, such as “children should avoid direct eye contact with the light source.”