Water and skin rash - stump care

[Artikel in Deutsch]

I return from holidays and my arm had been almost used up - wearing the prosthesis all day. The next working day, the people from the boiler service show up. They advertise as working without chemistry - so they mechanically remove calcification and replace some parts.

Now, what happened was that I got eczema on my stump. That is not normal as I usually have good success with the way I do my stump care.

Even after two weeks and with a dermatologist that prescribed various skin cremes, it only got better a little bit. It was burning, painful and red and bumpy.

I suspected a skin cream, some allergy, some overuse wearing the prosthetic arm maybe. But that turned out to be just a part of the issue.

I usually shower and wash myself outside from home (typically after sports) and so the only part that gets washed at home using luke warm tap water, that is my arm stump. But I did not notice anything peculiar at first.

Only two weeks later ...

... two weeks later, I got some vegetables ready in the kitchen, and when I cleaned the sink with hot water suddenly a strange smell alerted me that I may have to clean the sink.

I quickly found out that the hot water was opaque, foamy and stank heaps.

The whole 400L boiler tank turned out to be full of such stinking water that eventually turned yellow in the process of emptying the whole thing.

I had stinky discolored water run out of three taps at once for well over 1/2 hour.

What turned out to be the issue?

  • Two independent boiler / sanitary installation specialists agreed that it would be typical for acid usage to get a full 400L of such stinking water containing corrosion.  They said also it would be typical to use chemistry to decalcify boilers - in particular, formic acid (Ameisensäure), phosphoric acid (Phosphorsäure), hydrochloric acid (Salzsäure) and - left over at the end of the year - maybe hydrofluoric acid (Flusssäure). They also said that good practice requires to afterwards thoroughly rinse the boiler and add a neutralizer. Looks like that guy missed out on that.
  • The specialist that had decalcified the boiler said the discoloration was from rusty tubes but had no explanation to offer why there was yellow stinky water of almost 400L volume. I told him that discolored water did not just contain some 1/2 liter (or however little the tubes contained). but almost half an hour of water games running at full speed.
  • In my view, these guys definitely used chemicals. Maybe they rinsed the boiler a bit. Not very thoroughly but a bit. As I had only used minimal amounts of hot water over the two weeks followinng the boiler "cleaning" the remaining hot water must have gotten diluted with newly added fresh water only a little bit. So my arm stump was washed with that water.
  • The toxicologist at our local centre said that seeing as if my skin was already damaged previously (i.e., dry and sensitive) that it would be technically very hard to just look at it and distinguish allergy, infection and toxic reaction from some combined problem. But he said to consider another risk factor: not only would any acid damage my arm, also microbial build-up in the warm tubes could worsen my problems particularly in that situation.


  • If you get your boiler cleaned, stay there and watch them. If you don't know why you're doing it, they just may ;) If that is not possible, be careful afterwards and approach the situation as if you had a boiler filled with acid and corroded stuff. Rinse thoroughly.
  • Wash stump using cold water only. Due to less microbial build-up in the tubes and avoiding any heater system chemistry causing problems, that seems to be a better idea anyway. Rinse very thoroughly.
  • Rinse cold and hot water tubes regularly and sufficiently. That will allow the system to stay reasonably clean.

Cite this article:
Wolf Schweitzer: swisswuff.ch - Water and skin rash - stump care; published 26/12/2009, 05:01; URL: https://www.swisswuff.ch/tech/?p=249.

BibTeX: @MISC{schweitzer_wolf_1653033887, author = {Wolf Schweitzer}, title = {{swisswuff.ch - Water and skin rash - stump care}}, month = {December}, year = {2009}, url = {https://www.swisswuff.ch/tech/?p=249} }