Supposedly, D-Lead soap contains a "chelating" agent...that is, a chemical agent added to the soap which binds with metals in order to assist in their removal. These agents accomplish this by binding with the metallic ions.
Soaps, in general, are ionic cleaning agents which are composed of long chain molecules which have polar hydrophobic and hydrophillic ends to them. One end rejects water and the other end attracts it. Thus the soap molecule can attach one end to dirt and oils while the other end attaches to water, with the result of removing and suspending dirt and oils in water, which is then rinsed away.
Adding other chemicals to the basic soap can increase it's effectiveness in removing a variety of different substances and compounds.
There are other soaps out there which are marketed to do the same thing as D-Lead, one of which is Clean-All.
http://www.buycleanall.com/faqs.aspx
The CDC has licensed technology to a manufacturer (Mk-IX Technologies Corp.) specifically targeted at lead removal from the hands of workers at battery manufacturing plants.
http://online.wsj.com/article/SB123491637222104303.html
This technology is centered around adjusting the pH of the soap compound to a range which most effectively breaks up lead ions in/on the skin and the addition of a chelation compound to bind to the lead ions.
The problem, however, is that there doesn't seem to be much well publicized research into the actual effectiveness of the various methods and products. Pretty much all you'll find are corporate marketing claims and not independent research/verification. The two are not the same.
Here's what I found in one link:
There are a number of posts on this topic. Assuming we are concerned with litharge (lead oxide) and not other forms of lead, the main questions are:
(1) Can, and to what extent, does Lead get absorbed directly through the skin?
(2) What is the most effective means of removal of lead from the hands or other contaminated skin?
(1) Although most occupational medicine texts describe inorganic lead absorption via skin as negligible compared to inhalation or ingestion, there is actually very little research on this subject. Most of the experimental research has been done with lead salts (e.g., lead nitrate) which is not relevant to litharge. Experiments performed on laboratory animals are unreliable in extrapolating to human occupational exposures (and are also inhumane). What is well established, however, is that lead contamination on skin (mostly hands) significantly increases the risk of secondary ingestion or inhalation when food, beverages, or cigarettes are consumed. Basic handwashing with soap and water has been shown to be relatively effective at reducing such exposures.
(2) The question of whether a chelating agent (i.e., one that chemically binds metals) or proprietary soap/detergent product such as D-Lead(R) is more effective than ordinary hand soap or standard industrial hand cleaner. The latter contain various ingredients to assist in the mechanical removal of contaminants from the outer layer of the skin. This important industrial hygiene and occupational medicine questions has not received the research attention it deserves. Esca Tech, Inc., the manufacturer of D-Lead, cites one published article from 1997 on its web site. The study was limited in scope and did not utilize a reliable set of control subjects or measure effects over time.
These are important questions for people employed in the fire assay and related precious metals industry. I plan to conduct further research on these two related questions and will post a more detailed response in the near future. Please continue to post your own thoughts and experiences on this topic.
- James Craner, MD, MPH
Source:
http://www.fireassays.com/vb/showthread.php?15-Soap-to-remove-lead-from-hands&
As for a personal test, this is what I would recommend:
Anybody who has handled lead with their hands for any appreciable amount of time will see the dark lead markings left on the skin. Removal of these markings is one mark of the effectiveness of the soap (and scrubbing) used to wash it off. One could test the effectiveness of D-Lead by comparing how effective D-Lead is at removing these lead markings as compared to the regular soap one routinely uses.
If D-Lead does, indeed, make removal of these lead markings easier, then it's almost certainly more effective than whatever soap you normally use.
