Lighting safety in the vivarium
With all the publicity about ultra-violet (UV) light and skin cancer from the sun, are there any risks associated with reptile lamps that are used in the home?
The danger of over-exposure of human skin to the sun is well-documented. But are the emissions from even the most powerful reptile lamps truly re-creating these upper UV indexes found in the wild and also, if fitted properly in the vivarium, is there any risk of UV leakage into domestic living environment?
Firstly, I must emphasise that there is no evidence whatsoever of any danger at all from UV lamps when used in a typical vivarium. All of the UVB would be totally blocked by the toughened glass and plastics, so there is no measureable leakage into the living environment. In fact, UV cannot travel very far from the lamp, and this is why Arcadia Reptile HO-T5 lamps have proved so revolutionary, as they double the effective safe fitting range from lamp to animal.
Even with these new powerful lamps, the UV emissions would not be able to travel far enough from the enclosure to be of any real concern. A T5 reptile lamp has an eff ective gradient of about a meter (3.2ft) from the lamp, but at this point the average index would be less than 0.25, which is similar to the reading in the south of England on a summer day immediately before the sun sets.
Having said that, you should minimise your risk anyway. Keep the doors of the vivarium shut, as is necessary anyway, both to prevent the occupants escaping, and in order to maintain the temperature here. Minimise the amount of time that you spend servicing the vivarium, and if this is going to be protracted, then switch off the UV lamps before you start.
In a typical setup where a lamp is fi tted inside an enclosure, or included within a canopy fi tted over a mesh topped vivarium, there is no chance of human exposure as the light is limited to the enclosure and is prevented from entering the living environment by the glass.
With tortoise tables where mercury vapour lamps may be used, it is a good idea to use a deep dome fi tting which will conceal the whole lamp and focuses the light down on to the reptiles, in addition to reducing light spillage into the living area.
Where there could be a risk
It is also worth noting that it is UVC wavelengths that are most dangerous, not UVB. The only reptile lamps ever reported to leak UVC into the living space have been cheap Asian lamps off ered on online auction sites and the like. These lamps have been shown to use old-fashioned phosphor mixes and do not have a grade of glass that inhibits UVC production. Such lamps obviously do present a very real risk both to animal and keeper.
This is just one reason that I still feel that reptile lamps should be classed as medical devices and not available for anybody to import from the far east and sell from home! The risks are just too high. If you stick with a recognised, branded product though, then you should have no problems in this respect.
Don’t get SAD lights!
The other question that comes up frequently is the use of SAD (seasonal affective disorder) lamps with reptiles. I have to say that most of these lamps are simply a gimmick in my view. They use the phrase “Full Spectrum” which just means in reality that such lamps produce an attractive, natural daylight colour.
But there is a world of diff erence between full spectrum lighting and full spectrum plus UV. One of the most commonly-used SAD lamps for humans only has half of 1% UVB which is totally useless for reptiles. So the advice is don’t waste your money, or take a chance with your pet’s health and well-being.
As in all things, common sense is required. Although there is very little risk indeed associated with branded UV lamps sold for use with reptiles, keep your exposure to a minimum, turn the lamps off when maintenance is carried out, and never look at a light source. Finally, if you are aware that you have any medical risks associated with exposure to sunlight, always ensure that the reptile lamps are switched off before the enclosure doors are opened.
© John Courteney-Smith
Taken from “Practical Reptile Keeping” magazine