Despite many recent stories to the contrary, Soraa's CTO Mike Krames writes in his blog that LEDs are safe for lighting and that recent research on dangers was based on unrealistic eye exposure. Soraa also has restated its belief that the US Environmental Protection Agency (EPA) should adjust Energy Star efficacy requirements for solid-state lighting (SSL) products, now asking that 80–90-CRI lamps be held to a higher efficacy requirement.
Over the past few weeks there has been a flurry of stories, including many in the mainstream media, that cite recent research from a Madrid, Spain university that projects potential retina damage associated with LED lighting. Indeed, news sources such as MSN Now posted news of the Madrid Complutense University research as if it were fact. Apparently, however, the research didn't rely on eye exposure scenarios that are realistic.
The paper entitled "Effects of light-emitting diode radiations on human retinal pigment epithelial cells in vitro" was published in the Photochemistry and Photobiology scientific journal. The paper concludes that LED light, especially in the blue spectrum, can damage the retina cells and that those cells will not regenerate. The paper questions the safety of LED-backlit TV and computer displays and of LED lighting in homes, businesses, and street lights.
Soraa's Krames refuted the conclusions in a blog post entitled "Top ten myths of LEDs #10 – LEDs are dangerous." Krames points out that the experiments exposed eye cells to light intensity of 5 mW/cm2 for 12 hours. He said that the intensity level "corresponds to staring directly into a 100W-equivalent light bulb from about four inches away for 12 hours."
The research also directly linked LEDs with blue light or excess energy in the blue band within the human visual sensitivity range. Phosphor-converted LEDs that use blue emitters do typically exhibit an energy peak in the blue band because some photons pass through the phosphor. But there has still never been conclusive research on how significant a risk blue light poses. Moreover, there are studies that show exposure to blue light in the morning can increase our productivity.
Krames took the commentary on the research as an opportunity to point out that Soraa uses violet LEDs and the company's MR16 lamps have relatively even power distribution across the visual range. In fact, the SSL industry is moving to product designs that more closely mimic a blackbody radiator such as an incandescent lamp through the use of new phosphors and mixes of LED colors.
EPA and efficacy
Meanwhile, on the regulatory front, Soraa continues to lobby the EPA to level the playing field in Energy Star efficacy requirements. Previously, the company had asked for a reduction of 5–10 lm/W in lamps with a CRI of 90 or above. The company first made the request along with researchers, utilities, and a prominent lighting designer back in January.
Last week, the group again went public with a plea in response to the fact that the EPA did not act on the prior request in the latest draft of the Energy Star lamps specification. The group is now asking the EPA to require lamps in the 80–90 CRI range to deliver 5 lm/W higher efficacy than lamps with CRI above 90, recognizing that high CRI is documented to reduce efficacy.
Soraa and the other petitioners are concerned because Energy Star recognition is essentially a de facto requirement for customers seeking rebates or incentives for investing in energy-efficient lighting upgrades. The group in general believes that if the efficacy requirements are left unchanged, that the lighting industry will generally deliver lower-CRI lamps that more easily meet the current efficacy requirements. Soraa believes that adding a second CRI tier would provide buyers a fairer choice of higher efficacy or higher CRI.
Soraa and the loosely formed coalition believe that lower-CRI lamps will lead to poor buyer experiences and a slowdown in the adoption of LED lighting much like what occurred with compact fluorescent lamps (CFLs). They had argued that a slight reduction in efficacy requirements could actually broaden adoption of high-quality products and boost aggregate energy savings. Now they are simply asking for what they consider a level playing field for higher-quality lamps.
"Poor light quality ruined many consumers' confidence in compact fluorescents," said Soraa's Krames. "The Energy Star qualification must be associated with LED lamps that provide a better quality of light; otherwise, the program will start to lack credibility with end users and the low adoption rate history of CFLs will be repeated by LED lamps."
The EPA has said that it would still welcome comments on the issue. But with the release of the latest draft it also said that there were plenty of high-CRI products on the market already that met the requirements.