Energy saving light bulbs can emit levels of ultraviolet radiation sufficient to damage the skin, the Government's public health safety watchdog warned.
The agency issued what it described as "precautionary advice" yesterday after measuring levels of UV light emitted by the bulbs at the request of patient groups. They have complained that they aggravate light-sensitive conditions such as the blood disease lupus, eczema and porphyria, which together affect tens of thousands of patients across the UK.
Energy saving bulbs, also called compact fluorescent lights, have been on the market for more than 20 years and come in two types – "open" with the glass coil clearly visible, and "encapsulated" where the coil is enclosed in a second layer of glass and looks more like a conventional light bulb.
The research showed that one in five of the "open" bulbs emitted UV light equivalent to that experienced on "a sunny day in summer" when in very close proximity (less than one inch) to the skin, which warranted "some precaution". When the light was moved further away, beyond one foot, the UV level was below the exposure on a sunny day in winter and was "not a concern".
Open bulbs should not be used where the user is closer than one foot for more than one hour a day, the agency said. Encapsulated lights with a double glass envelope did not emit significant amounts of UV light, the research found, and could be used in place of the open kind for close work.
The problem only occurs when the lights are used for close work, such as in desk lamps or reading lights. When the light is more than one foot away there is no danger, the Health Protection Agency (HPA) said.
Justin McCracken, the chief executive of the HPA, said it was calling for product standards to be tightened under EU legislation. Measurements made when the lights first came on the market in the mid-1980s had not disclosed a problem. In the meantime it was right that the public should be warned about the existing bulbs, especially if they suffered from light-sensitive conditions.
"People should not be thinking of removing these energy saving light bulbs from their homes. If you need to use one closer than one foot away, it's a simple adjustment – either move the light or replace it with an encapsulated bulb. I walked round my own home and found none of my energy saving bulbs were used closer than one foot. In situations where people are not likely to be very close to the bulbs for any length of time, all types of compact fluorescent light bulbs are safe to use."
He dismissed suggestions that close exposure to the UV light emitted by the bulbs could cause cancer. "That is not what we are saying. At the exposure levels that we are talking about, the worst is that you could have short-term reddening of the skin. We do not believe these lights pose any risk in terms of skin cancer." However, people with light-sensitive conditions "need to be careful", he added.