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Cadmium, simple test for?

Cadmium plating was used for some tools

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Nicholas Farr17/12/2011 10:47:22
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Hi Peter, you can be/become allergic to anything at any time in your life, I don't believe toxicity has much direct connection with being allergic to anything, after all some foods which have no toxins in are allergic to some people. Toxins will make just about anyone ill or have a fatal outcome, either in a short or long term.
 
Regards Nick.
Billy Mills17/12/2011 12:57:04
377 forum posts
Very low level long term exposure can cause tolerance to develop to substances that are lethal in small doses but sometimes low level long term exposure can also lead to sensitisation to other substances, it is a very complex issue.

A very interesting study of the animals living around Chernobyl has shown that long term exposure to radiation levels way above normal limits has not lead to the expected DNA defects but to the development of a remarkable resistance to ionising radiation. Another major benefit to these animals has been the almost total exclusion of man.
 
Allergic reaction and food intolerance was just not around decades ago, either a very large proportion of the population has been sensitised or we did not recognise the problems.
 
I did A level Chemistry semi micro anl 40 years ago. I think the Cd test used dilute Hydrochloric acid to put the metal into solution then Hydrogen Sulphide gas was bubbled through to create a precipitate which was then nitrated then conc Sulphuric was used to produce a yellow precipitate, could be a bit out after 40 years. Not the sort of test easily done at home. The flame colour was light blue but you would not want to do that these days unless you were certificated insane.
 
Many of the nasty heavy metals tend to form insoluble white carbonates when weathered which is why lead pipes are not that dangerous.
 
Billy.

 
 
Mark P.17/12/2011 17:44:08
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I really wouldn't worry about cadmium,I for one will not loose any sleep over it. We are constantly bombarded with health and safety & food scares we are loosing sight of reality,eat more lard I say!
 
Pailo.
Paul Fallert17/12/2011 19:10:58
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Pailo:
The medical case (Lucas, 1980) mentioned above brought the issue to my attention by a friend.
 
The welder in that case only worked for 30 minutes with his (notably) high temperature torch on the silver soldering project. That's all it took to kill him. The silver solder only contained a minute amount of cadmium, but it was vaporized by the torch and he inhaled the fumes. Some are more susceptible than others to toxics.
 
One of our famous posters claims to down several pints per day and he's still with us ( I think )...come to thing of it, he has not posted for a while. I hope he is OK.
 
Paul
Stub Mandrel17/12/2011 21:26:40
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There's more than a minute amount in teh easyflo solders.
 
I have read about taht fatality, and if I recall correctly the problem was poor ventilation combined with use of an oxy-acetylene torch - result too hot so the cadmium boils out of the solder...
 
Neil
Ian S C18/12/2011 10:40:02
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A few years ago a bloke in NZ died after welding galvanised iron in the freezer of a fishing boat at sea, the effect of zinc in an unventilated space. Ian S C
KWIL18/12/2011 11:00:41
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Neil makes it quite clear, it is the lack of proper ventilation you should worry about.
 
I have used cadmium included silversolder for the last 58 years and also been around oxy-acetylene / oxy-propane and silver solder part of that time. Still here!!


Edited By KWIL on 18/12/2011 11:01:46

Paul Fallert18/12/2011 17:40:44
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Cadmium ID - an materials engineer told me today that cadmium platers can give the finish any color. He worked his for a multi-national switchgear company and was in the testing department. Visual will not be reliable.
 
On the other hand, I tried the fingernail test on some samples of nuts and bolts. I pressed a thumbnail as hard as i could into the surface and examined the results.
 
Nickel - no mark
Chrome - no mark
zinc - no mark
 
Cadmium - left a definite (but not deep) scratch that would not wipe off.
 
For comparison, I have a piece of world famous Stephenson-Blake letterpress foundry type metal (alloy of lead, tin, antimony). No mark.
 
Is that indicative?
 
Paul
John Haine18/12/2011 18:23:04
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Long ago in A-level chemistry learning qualitative analysis the test for cadmium was to look at the colour of a bunsen flame in which one held a little loop of wire with a drop of the salt on it. You could dissolve a bit of an unknown metal in some dilute acid. Bunsen had to be adjusted for a colourless flame first. IIRC cadmium gives a scarlet red flame. Our enlightened teacher encouraged us to set fire to small pieces of the metal on a gauze over a bunsen - lovely colour intense red flame. I don't think many of my chemistry classmates succumbed to anything nasty.
 
Anyway there's your answer. Rub a little acid (vinegar would probably do the trick) on the plating, then use the end of a bit of clean copper wire to pick up a little of the liquid and see if you get a red flame (before the copper gets too hot and gives you a green one).
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