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Lead scrap includes lead-acid batteries, cable coverings, pipes, sheets and lead coated, or terne bearing, metals. Solder, product waste and dross may also be recovered for its small lead content. Most secondary lead is used in batteries. To recover lead from a battery, the battery is broken and the components are classified.
The problem was addressed in 2004 by adding additional treatments to the water, preventing the chloramine from dissolving lead in the water mains, solder joints, and plumbing fixtures. In 2010, the CDC reported that 15,000 homes in the Washington, D.C., area might still have water supplies with dangerous levels of lead.
As hot water is more likely than cold water to contain higher amounts of lead, only cold water from the tap should be used for drinking, cooking, and making baby formula. Since most of the lead in household water usually comes from plumbing in the house and not from the local water supply, using cold water can avoid lead exposure. [223]
Lead-based house paint banned by the Consumer Product Safety Commission [9] 1986 Amendments to the Safe Drinking Water Act require new drinking-water waterpipes, solder, and flux to be "lead-free"; however, this is defined as less than 8% lead in pipes, and 0.2% in solder and flux. [10]
The fumes liberated during soldering have adverse health effects, and volatile organic compounds can be outgassed during processing; The solvents required for post-soldering cleaning of the boards are expensive and may have adverse environmental impact; In special cases the drawbacks are sufficiently serious to warrant using fluxless techniques.
In modern times, lead was still widely used in water distribution systems and plumbing hardware before the early 20th century, including lead pipes, leaded solder and leaded alloys. [8] One part of the system is the connections between the water mains and the water user locations.
The more common lead-free solder systems have a higher melting point, e.g. a 30 °C typical difference for tin-silver-copper alloys, but wave soldering temperatures are approximately the same at ~255 °C; [47] however at this temperature most typical lead-free solders have longer wetting times than eutectic Pb/Sn 37:63 solder. [49]
Thermal stress on the electronic assembly is kept as low as possible to prevent unnecessary contractions of the board which might cause immediate or future damage. In the 21st century, almost all soldering is carried out with lead-free solder, both on manufactured assemblies and in rework, to avoid the health and environmental hazards of lead ...