IMPLEMENTING LEAD FREE SOLDDERING - EUROPEAN CONSORTIUM RESEARCH
Author: Dr. Malcolm Warwick Company: Multicore Solders Ltd. Date Published: 10/1/1999
Abstract: Lead is one of those materials that man has used throughout history because it is easily extracted and refined with relatively low energy costs, and it has a range of useful properties. The significant problem with the material however is its mammalian toxicity, and this has driven its elimination from applications where there is an effective substitute. It has been removed from food and water contact applications such as potable water distribution systems and food cans, and it has been largely eliminated from automotive fuel and paint formulations. In some countries, it has been replaced in PVC stabilisers, ammunition and fishing weights. Of course there are still very large applications for lead, particularly in the ubiquitous accumulator in every automobile and many stationary back-up power systems. However, this is not an acceptable justification for the continued use of the element in smaller applications if there is an alternative. Consequently, the relatively small use of lead in soldering in the electrical and electronics industry started to receive attention from environmentalists and legislators about ten years ago. The toxicity of lead towards its immediate users was not the main driver for elimination from soldering. However, the redistribution of the material into the environment via the landfill of “spent” electronic equipment was seen to present a long-term problem for groundwater purity. The table below gives some indication of the relative risks of lead ingestion by different routes.