What daHermit says
This is an indication of the level of complexity of the issue.
In an attempt to make myself more knowledgeable I put a call in to the tech manager at one of the larger wheel weight manufacturers. She was surprised to learn that I was not some tree hugging wacko. What I wanted was simple facts for my own use and not to crash the Republican National Convention.
I made this call about four years ago.
She said:
1. The proportion of lead in wheel weights is kept high for financial reasons. If there is much other stuff in the metal it is very likely something that is substantially more valuable than lead. She mentioned tin, antimony, bismuth and "others". My additional comment here is that it may also raise the smelting temperature which adds to the cost of the process.
2. The proportion can only economically go so high since the purification of lead or the acquisition of pure lead is expensive and so the price goes up for that reason. They don't purify the lead, they smelt what they get.
3. A given batch of weights will be somewhere above 95% pure lead. But the actual purity of that batch is hard to predict since it relies upon what they get. (Remember, this was four years ago.)
4. The picture goes more and more out of focus since a rising percentage of the weights in use come from China. In her words (four years ago) nobody knows what the Chinese are putting in their weights.
When I did this cursory inquiry there wasn't much information on the web about weights. Now there is.
Presently, eleven states have either banned lead weights, are considering a ban or ban the use on state owned vehicles. That was also four years ago.
Here is another thought:
You can conveniently write a law that controls lead proportion in three parts of the process. Manufacture, distribution and use.
In the manufacturing process you can test the materials that go into the process and the weights that come out of it.
In the distribution part you can make it illegal to sell weights that contain lead (or an excessive percent of it)
In the use part you can hold owners and operators of vehicles accountable.
When you think about it, enforcement of all of this is expensive and none of it is easy.
Ever have a regulator come to you and tell you he was confiscating the wheel weights from your car to test them?
Those regulations covering manufacture would not apply in China. Imported weights would have to be regulated either through distribution or use.
What about the distribution piece? Does the government confiscate samples of weights that are sold for example by Grainger or others and test them? Or do they require that the distributor state that the weights are lead free? And if that is the case, can the distributor cite statements by the manufacturer as to the lead content as happens with formaldehyde in laminate flooring?
When I was on active duty, my ship was in the yards for a maintenance period. We were required to lay plywood on the interior decks and flooring to prevent damage to the floor from equipment being moved around.
My division got hold of about forty sheets of plywood and stacked them for use the following day. An inspector happened by and looked at the plywood promptly and firmly declaring we could not use it since it was not "Flame Retardant".
My people were crushed since this setback would delay virtually everything we wanted to do.
"Not to worry." I declared. I had two Chiefs working for me. After the work day ended and all of the inspectors were gone, we made up a stencil that said "Flame Retardant" and marked the first five sheets of plywood in the stack.
The next day we found the inspector and showed him the plywood. Same plywood, same stack, same location, same inspector. He read the markings on the plywood (paint still wet from the evolution).
His ruling; "Well done sir, carry on."
