Solders, lead-based

Arsenic added ia amounts of 0.1—3% improves the properties of lead-base babbitt alloys used for beatings (see Bearing materials). Arsenic (up to 0.75%), has been added to type metal to increase hardness and castabiUty (21). Addition of arsenic (0.1%) produces a desirable fine-grain effect in electrotype metal without appreciably affecting the hardness or ductihty. Arsenic (0.5—2%) improves the sphericity of lead ammunition. Automotive body solder of the composition 92% Pb, 5.0% Sb, and 2.5% Sn, contains 0.50% arsenic (see Solders and brazing alloys). 

During the 1960s, Americans lived in a lead-drenched society. They fueled their cars with leaded, antiknock gasoline. They ate food and their babies drank milk from lead-soldered cans. They stored drinking water in lead-lined tanks and transported it through lead or lead-soldered pipes. They squeezed toothpaste from lead-lined tubes and poured wine from bottles sealed with lead-covered corks. They picked fruit sprayed with lead arsenate pesticide and served it on lead-glazed dishes in houses painted and puttied with lead-based compounds. 

Lead-based paint— Present on many surfaces in homes not recently rebuilt or remodeled Lead pipes— More common in older homes Lead solder— On pipes and water heaters Enameled or ceramic pots and dishware—Improper glazing can leach lead into foods Paper wrappings— Holiday paper and party decorations (10 g/kg)... 

The environmental impact of waste disposal and of chemical use in Europe has led to three legislative actions that, in today s global economy, greatly affect flame-retardant use and research. These actions go by the acronyms of RoHS (Reduction of Hazardous Substances), WEEE (Waste Electrical and Electronic Equipment), and REACH (Registration, Evaluation, Authorisation, and Restriction of Chemical substances). These actions are discussed in detail in Chapter 22, but need to be mentioned here as they are clear examples of how changing regulations affect flame-retardant use, selection, and new fire-safety developments. The first one, RoHS, refers to how new items are manufactured, and specifically bans chemicals and elements of environmental and toxicological concern in Europe. One fall-out item of RoHS is the move from a lead-based solder on circuit... 

Lead and lead-based solders Trichloroethylene Abrasion. Grit or vapor blast, or 100-grit emery cloth followed by solvent degreasing ... 

Byrne cell — This was a chromic acid-zinc -> battery where the inert electrode was made from copper with a lead coverage on which the platinum electrode was soldered. The copper and lead base was used to reduce the resistance of the, usually, thin platinum wires. 

A major problem in the analysis of lead-based alloys is the selection of a suitable solvent mixture. Price [7] has described a method based on hydro-bromic acid/bromine. The disadvantage of this method is that the solvent mixture is unpleasant to handle and precipitation often occurs on dilution. Hwang [8] has described a method for the analysis of trace and minor elements in lead/tin solders using a solvent mixture of fluoboric acid and nitric acid. 

Instrumental parameters for the analysis of lead-based alloys are shown in Table 7 and results obtained by Hwang [8] for the analysis of impurities in lead solder are shown in Table 8. 

The main anthropogenic sources of lead include lead-based paints, solder, and metallurgy. Even though utilization of the alkyllead compounds such as gasoline additives has already been regulated, the persistence of various lead forms in the environment is still an issue (Table 3). ICP-MS detection of lead has been used in hyphenation of GC, ion exchange, ion-pairing LC, and, to a lesser extent, SFC. The... 

EXPOSURE ROUTES leaded gasoline combustion combustion of solid waste, coal, and oils emissions from iron and steel production lead smelters tobacco smoke food and soil lead-based paints flaking paint paint chips weathered paint powder drinking water pipes, solder, and fixtures lead smelting and refining industries steel and iron factories gasoline stations battery manufacturing plants... 

Sadly, this story is more relevant to today s society than you might think. Lead-based solder was widely used for many years to connect the copper pipes in... 

Aquatic lead pollution has been an environmental and public health issue since ancient times (3). Widespread use of lead pipes, lead-lined storage tanks, and pipes joined with lead-based solder led to contamination of drinking water... 

The composition and pH of water also affect the oxidation of lead metal. Modern drinking water treatment is highly effective at removing lead from water before it is pumped to the consumer most water contamination comes from corrosion in distribution systems, that is, lead pipes and lead-based solder (408). Under acidic or neutral conditions in the presence of oxygen, metallic lead is readily oxidized to Pb ", as can be seen from the equations below and from Figure 21 (48, 408, 409). 

Subramanian KS, Connor JW, Meranger JC. 1991. Leaching of antimony, cadmium, copper, lead, silver, tin and zinc from copper piping with non-lead-based soldered joints. J Environ Sci Health A26(6) 911-929. 

Whilst lead pipes are the main somce of high lead concentrations, lead concentrations higher than 10 4g/l can also be observed for properties without any lead pipes. Lead-based solders (for copper plumbing), copper alloys (brasses and bronzes) used mainly for fittings, galvanized steel pipes and uPVC (when stabilized with lead salts) can release lead into drinking water. 

Lead based solders (tin/lead solders) contain up to 60 % of lead, which can be released into water through galvanic corrosion. The corrosion rate is increased by high concentrations of chloride and nitrate but is inhibited by sulfate, silicate and orthophosphate. Lead concentrations at the tap depend not only on the corrosion rate but also on the number of leaded joints in the plumbing, the area of solder exposed to water at each joint, and the water usage pattern (Gregory, 1990). 

Sadly, this story is more relevant to today s society than you might think. Lead-based solder was widely used for many years to connect the copper pipes in water systems in homes and commercial buildings. There is evidence that dangerous amounts of lead can be leached from these soldered joints into drinking water. In fact, large... 

So many industrial and commercial uses have been found for Pb that it is difficult to list them all. The main uses of Pb which are most relevant to environmental contamination and human exposure are lead-based indoor paints, lead water pipes, lead solder in cans for storing food, and leaded gasoline additives these have either since been banned or are in the process of being banned. Action is also being taken with respect to lead glazes on pottery and ceramics, lead in... 

Over the past 30 years, many lead-based products have disappeared from use or the use has been greatly diminished. These products include lead-based paints, lead-based anti-knock compounds for automobiles, lead glazes for pottery, lead sealants for wine battles, solder for sealing the seams of steel cans, automobile body solder, solders for potable water systems, solder for sealing copper radiators, chemical tank linings, lead pipes, lead-based metal bearings, lead sealants such as for drain pipes, power and electrical cable sheathing, and ammunition. 

Data sheets are available where a range of information is available and where you can obtain the information required for your application. Table 20,1 shows data relating to a range of tin-lead base solders and... 

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