The matter is discussed openly and the various options are considered.
The Danger of Lead
Lead poisoning has been the subject of many investigations, from the danger to children of eating peeling lead based paint, to the jeopardy from handling lead products. The danger of poisoning from ingesting lead certainly exists and caution must be taken whenever lead is open to the environment. The danger however is often exaggerated, and with reasonable caution any jeopardy can be controlled. The main danger of lead poisoning comes from three areas.
1). Ingesting lead from contacting the metal with hands and fingers and then transferring the lead contamination to food, cigarettes or other items that contact the mouth or tongue. There is the less likely possibility of absorbing lead through the skin.
2). Breathing tiny particles of lead from dust in the air. These usually arise from such operations as grinding or sanding items containing lead. Molten lead which is violently disturbed as for example air blasting the solder from joints during repairs is also a source of danger.
3). Eating or drinking food or liquid contaminated with lead . For example water from pipes joined with lead bearing solders, or food prepared on lead bearing metal surfaces.
The Precautions
Simple precautions can virtually eliminate this danger. For example anyone exposed to lead must thoroughly wash their hands before any eating, drinking or smoking. If exposed to lead dust shower thoroughly immediately the work is finished. Good air filtration in the working place is absolutely necessary, effective for the particle sizes being generated. Grinding under a water spray, and similar techniques that are readily available should also be applied. Masks should be used when ever there is a danger of lead contaminated air.
Good housekeeping is mandatory including changing clothes at the end of a shift, showering and washing the hair to remove all lead particles. Item three is more complex but all water and food processing equipment should be checked for the presence of lead. Some old buildings still retain lead pipes, but in many cases hard water lines them with calcium and renders them harmless. Soft water on the other hand may be slightly acidic and can pick up a dangerous amount of lead from contact with lead pipes or lead bearing solders.
Lead Free Solders
There are no lead-free “drop in” substitutes for tin/lead solders, the process will usually have to be modified in such areas as soldering temperatures and techniques. The questions of strength, ease of use and cost must also be considered. It is pointless changing to lead-free solders if the products being worked on contain lead. For example one radiator repair shop was concerned at the high lead level found in the blood of their employees, as they had changed over completely to lead-free solders. They forgot that the radiators they were repairing had been made using lead based solders and therefore they could not relax their environmental precautions.
A Caution
The greatest jeopardy to the general health of the public lies in the disposal of lead bearing products in land fill which may eventually leach into the water supply. If we follow a recycling policy in our manufacturing plants we can avoid this danger. Any use of lead therefore must be sensibly controlled, using good housekeeping practices, and ensuring that any lead bearing materials are properly disposed of and not allowed to get into the environment.
Hirsch Metals is a top supplier of solders including ones that are lead free. Browse our site or give us a call at 800-521-0352.