Is mercury a mixture

Department of biology, chemistry, pharmacy

Some history got to be:

You have grown up with fluorescent lamps (fluorescent tubes, incorrectly also called "neon tubes") all your life. To your satisfaction, these lamps have always illuminated the interior of department stores, parking garages, public transport, cellars - even the chic mirror cabinet in your bathroom, living room cabinet or aquarium pleasantly without shadows or as a so-called "black light" in the disco for the right one Mood taken care of. Thanks to technical progress, these fluorescent lamps can now be made so small that you can mount them on the base of a lightbulb and replace the lightbulb with the energy-saving lamp obtained in this way.

So far this has not been a problem in anyone's eyes, only now, when consumers have been banned from the light bulb they have come to love, self-appointed experts suddenly appear who, as "light biologists", want to persuade us to produce unhealthy flickering light (which modern ballasts have long since eliminated has) or complain about color falsifications (artists complain about this and they may be right. As an everyday user, however, I have never experienced this as a problem.) In particular, there are also hysterics who brand the mercury it contains as the devil's stuff.

The mercury is the actual source of light in a fluorescent lamp, including every energy-saving lamp. So it doesn't work without it! To do this, the mercury has to evaporate in the lamp, which it does better when it is heated than when it is cold, which is why energy-saving lamps typically only reach their full luminous intensity after a while.

In the past, when you didn't care about the mercury in the "neon tubes", they contained up to 200 mg of mercury, which you could see back and forth in the curves of the car lights of the Berlin S-Bahn in the "GDR times" could see a rocking droplet. Nowadays, compact fluorescent lamps must not contain more than 2.5 mg of mercury. Modern light sources get by with 1.5 mg today. Already burdened with 8 maximum permissible Fish meals absorb more mercury than is in the broken lamp.

If you break an energy-saving lamp, however, the mercury will not flop out of the glass, but rather it is mainly finely distributed in the whitish coating on the inside of the glass wall, which is also responsible for the fact that the mercury actually generated hard UV radiation is completely converted into pleasant, visible light during operation. The fine distribution of the mercury is due to the fact that the mercury in the lamp has already evaporated many times and then condensed again. You know it from showering: Afterwards, the entire bathroom wall is damp and the condensed water unfortunately does not collect directly at the floor drain so that it can be easily disposed of with a push of a scrubber.

If an energy-saving lamp breaks, it has the disadvantage that the mercury evaporates quickly from the large surface. You are also familiar with this from the bathroom: if you ventilate the bathroom after showering, the water will evaporate from the wall much faster than if it were a puddle waiting for the scrubber blow. The energy-saving lamp therefore releases the most relevant amount of mercury immediately after it breaks - and afterwards it doesn't have much to offer. Measurements of the Bavarian State Office for Health and Food Safety, whereby under different conditions energy saving lamps in a 50 m3 large space was broken and the mercury content was observed for about 100 hours. So if you ventilate away the mercury released after the breakage, the box should be largely quiet again.

Because people are afraid of mercury, the manufacturers of energy-saving lamps are writing more and more clearly on the packaging that the lamp no longer contains any mercury, but an amalgam - a mercury alloy. It's a mixture of mercury and other metals. In fact, this has advantages: the amalgam is no longer liquid, but a small, solid globule. If the new lamp rattles when you shake it, it is probably the amalgam ball and nothing is broken. When the package says thickly "No mercury, just amalgam" and it rattles Not, then you have not bought the lamp from a fraudster, but the amalgam ball is in a small cage and can no longer rattle. If such an amalgam lamp breaks, there cannot be any free mercury in the lamp, only the white coating on which the mercury is adsorbed and the amalgam ball. Even if the amalgam ball gets into the vacuum cleaner: The mercury is immobilized there and cannot crawl into cracks or contaminate metal parts of your vacuum cleaner through amalgamation. The amalgam ball still emits mercury vapor, which the vacuum cleaner blows out at the back, but as soon as you have changed the dust bag, the ball is gone and everything is residue-free as before.

You know "amalgam" as a tooth filling. This shows that amalgams can be so harmless that you can even keep them in your mouth permanently. But not every amalgam is the same. Your tooth filling should, for example nothing Mercury vapor develops, but the amalgam ball in the fluorescent lamp does. According to the measurements of the Bavarian State Office for Health and Food Safety but it seems to be the case that an energy-saving lamp with amalgam releases less mercury when it breaks than an energy-saving lamp with pure mercury.

There are fluorescent lamps in which the glass bodies are in break-proof housings made of transparent plastic. The declared energy efficiency then often seems to be a little lower - perhaps because you then don't have that much space for the glass tubes into which they can emit their light - but there is a good chance that these lamps will both be a bit too brash Screwing in or plugging in as well as surviving a fall unharmed, or at least surviving without releasing mercury.

-> Back