Fluorescent tubes, energy-saving lamps and xenon lamps contain mercury. But car lamps are the only technology where you also get newer, mercury-free types. For environmentally friendly people there is the question of upgrading.
But before you get ahead of yourselves: it’s not possible. I’ll tell you later why that is. There would be good reasons for an upgrade. Mercury is a health risk. Therefore, in the European Union and other parts of the world its use was banned or at least extremely restricted for most applications. This also includes xenon lamps, although their beginnings in car lights were voluntary. Japan and its car industry was the driving force behind it. Tuna becomes particularly polluted with the metal which is already liquid at room temperature, and the fish is one of Japan’s favorite foods. But I’m getting sidetracked.
In the first decade of the 21st century, Osram and other major manufacturers of xenon lamps started developing and producing lamps without the shiny silvery metal. The results speak for themselves: the new D3 and D4 types produce the same great light as the older D1 and D2 versions. So there are no disadvantages. It would make sense to use these lamps when replacing the worn out ones.
Different operating voltage
That’s not going to work though. D1 and D2 work at an operating voltage of 90 volts. The mercury-free types are only supplied with about half that amount. There are physical reasons for that and it has to do with the composition of the gas and salts in the lamp. There are no other reasons. Otherwise the industry would have loved to offer like-for-like replacements. Upgrading an old headlight to the new operating voltage would mean replacing the control devices and converting the holder for the lamp – because the lamp bases are different so that no one can accidentally fit the wrong lamp. In any case, the cost for such a conversion would probably be in the same region as the price for a new headlight.
Many cars have long been available only with D3, D4 or the (rare) D5 and D8 25-watt versions which are all free of Hg. The abbreviation is the chemical symbol for hydrargyrum, which is Latin for mercury. The old types are no longer allowed to be fitted in new vehicles. Old xenon lamps can still be used as a replacement without restrictions. That’s the first good news.
The second involves the dangers of mercury in xenon lamps. They are very clearly below the ones for fluorescent and energy-saving lamps. For one, a D1 or D2 contains a lot less mercury. In addition, most xenon lamps are replaced in garages where the old ones are (hopefully) disposed of in an environmentally friendly way. Household lamps with mercury, on the other hand, very often end up in landfill. What’s more, Osram was able to reduce the amount of metal that is harmful to human health in the old lamp types. That’s the third good news.