The other problem with saying there is no lead in something, is that what is meant by no lead. In analytical chemistry, we will say something like there is lead was below the detection limits of the method. Now that does sound legalistic, but it is really stating the fact that we were not able to measure any lead down to a particular concentration, so if there is lead it is below the concentration we can detect.
Up in the lab we have an instrument (Varian 820 ICP-MS) that will detect a lot of metals to better than parts per billion (ppb). I just checked the spec sheet and it should typically detect lead to 0.1 ng/L which is better than what I recall. That is 0.0001 ppb or one part in 10,000,000,000,000.(Hopefully I have the zeros right ... I always lose a few at the whiteboard teaching class)
What is an acceptable amount of lead? We have exposure in many places. The WHO (World Health Organization) has a limit for drinking water of 10 micrograms/Liter (or 10,000 ng/L to put it in the same units as the detection limits) , and the EU statutory limit is 50 micrograms/Liter. The same reference I found indicated that blood levels of lead in Europeans had fallen below 10 micrograms/deciliter in the 1990s. (that is 100 micrograms/L or 100,000 ng/L).
Point is: We can detect lead at a much lower level than would be biologically significant. So a company will state that they comply with the lead regulations, but will probably never say there is no lead in something. (or they may say there is no detectable lead, but run the risk of a crafty chemist figuring out how to improve the detection limits)
John
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