EDINBURGH – Physicians may want to avoid exposing their photosensitive patients to single-envelope compact fluorescent lamps. Better to use the double-envelope variety, Dr. Harry Moseley suggested.
“Ultraviolet emissions from single-envelope compact fluorescent lamps can be harmful to patients with light-sensitive skin disorders,” Dr. Moseley said at the 15th World Congress on Cancers of the Skin.
Compact fluorescent lamps (CFLs) contain small amounts of mercury that, when stimulated, produce ultraviolet radiation. Double-envelope CFLs encase the standard twisted CFL bulb in a glass or plastic shell, thereby lowering the UV risk.
Extensive testing of 280 lamps, including 106 single-envelope CFLs, by Dr. Moseley and others revealed sizable variations in emissions below the 400-nm threshold in the UVC (280-100 nm), UVB (280-315 nm), and UVA (315-400 nm) wavelengths.
The average UVC, UVB, UVA2, and UVA1 milliwatts per square meter from double-envelope CFLs was 0.02, 4, 11, and 408, respectively, compared with 2, 99, 81, and 989 milliwatts per square meter for single-envelope lamps (Photodermatol. Photoimmunol. Photomed. 2014;30:153-9; Br. J. Dermatol. 2013;169;910-5; Photochem. Photobiol. Sci. 2012;11:1346-55).
“So now we have something we can take to our photosensitive patients,” Dr. Moseley, head of scientific services at the photobiology unit, University of Dundee (Scotland), said.
Newer light-emitting diodes provide an even safer alternative, with no UV emissions detected below 380 nm in the lab, he added.
In its most recent 2011 report, the Scientific Committee on Emerging and Newly Identified Health Risks (SCENIHR) also acknowledged the benefits of LEDs to reduce UV radiation exposure.
A preliminary case report by Dr. Moseley involving just four patients with chronic actinic dermatitis (Br. J. Dermatol. 2009;160:659-664) prompted SCENIHR to issue its first warning about single-envelope CFLs in 2008 and recommend the use of double-envelope CFLs.
“The lighting industry said we were being too strict, and the patient pressure groups said we weren’t being strict enough, so I’m assuming we must have been about right,” he recalled.
Subsequent testing in 200 patients, 154 of whom were actively photosensitive, produced 32 positive responses to exposure from single-envelope CFLs at a distance of 5 cm.
Because CFLs don’t emit heat like old-fashioned incandescent bulbs, however, patients frequently place these lamps quite close to their face or hands when reading or doing intricate work, Dr. Moseley observed.
In the United States, the Food and Drug Administration has worked with the lighting industry to require a caution label on general-purpose lighting that exceeds the Illuminating Engineering Society of North America’s radiation emission standards. The FDA states that CFLs carry no such warning because UV levels fall “below the level of concern” when used at typical-use distances by healthy individuals.
“The problem is that when you’re buying these lamps, you don’t know how much UV is coming out of them because there is nothing on the packet that will tell you this kind of information you may be interested in,” he said at the meeting, sponsored by the Skin Cancer Foundation.