Lead capsules

Although dietary lead intakes in the UK are currently well within recommended intakes, it is the UK Government s policy to ensure that exposure to lead is reduced wherever practicable and, more specifically, to reduce blood lead levels in children to below 10 pg/dl. Food is one of the major sources of lead exposure in the UK the others are air (mainly lead dust originating from petrol) and drinking water. Exposure from all of these sources has been reduced, as demonstrated by the reduction in blood levels over the past 15 years.10 The decrease in dietary exposure reflects the success of the measures taken to reduce lead exposure and contamination of food, such as the use of lead-free petrol, welded food cans, and the banning of tin-coated lead capsules for wine bottles. 

Other environmental strategies include eliminating lead capsules by replacing them with a beeswax stopper. Fetzer s organic range of wines called Bonterra is packaged in recycled glass bottles, with labels made out of kenaf (paperless hemp), printed with soy-based ink. 

The test may also be conducted in a small lead capsule, provided with a close-fitting lid made from lead foil. A small hole of about 3 mm diameter is pierced in the lid. About 0-1 g suspected fluoride and a few drops concentrated sulphuric acid are placed in the clean capsule, and a small piece of glass (e.g. a microscope slide) is placed over the hole in the lid. Upon warming very gently (best on a water bath) it will be found that an etched spot appears on the glass where it covers the hole. 

Concentrated sulphuric acid silicon tetrailuoride and hydrogen fluoride are evolved on warming the reagent with the solid salt. If the reaction is carried out in a platinum or lead capsule or crucible, the escaping gas will etch glass and will cause a drop of water to become turbid (see under Silicates, Section IV.26, reaction 6). 

May contain Si02.f Confirm by microcosmic bead test or by the SiF4 test in lead capsule. 

Fluoride. A portion of the dried residue (or of the original mixture) may be decomposed with concentrated sulphuric acid. Heat in a lead capsule or crucible with concentrated sulphuric acid and apply the etching test (Section IV.17, reaction 2). Alternatively, the water test (Section V.18, reaction 8) may be used. 

Lead-tin capsules are also a source of lead in wine. Jaulmes et al. attracted attention to this source of contamination as early as 1960. Capsules for still wines used to be made of lead covered with a thin layer of tin. Although the permeability of corks is minimal, there may be a slight leakage of wine that oxidizes to form acetic acid. This can erode the capsule, producing lead acetate. Contamination occurs mainly when the wine is poured. One study showed that the first glass poured from a bottle could contain up to 20 mg/1 of lead. Lead capsules have since been banned. 

Federal studies in 1991 found that up to 4% of the wine in the United States contains dangerous levels of lead. This is largely due to the leaching of the lead from the foil that is wrapped around the cork and neck of many wine bottles to keep out insects and oxygen. These CAPSULES used to be made from tin but manufacturers switched to lead because it was less expensive. Although this use of lead is now prohibited, many imported wines that were bottled before 1996 still have lead capsules. 

The use of lead capsules for wine bottled after February 1996 is prohibited as an adulteration. ... 

Several compounds such as BaZrS [12026-44-7], SrZrS [12143-75-8], and CaZrS [59087-48-8], have been made by reacting carbon disulfide with the corresponding zirconate at high temperature (141), whereas PbZrS [12510-11-1] was produced from the elements zirconium and sulfur plus lead sulfide sealed in a platinum capsule which was then pressurized and heated (142). Lithium zirconium disulfide [55964-34-6], LiZrS2, was also synthesized. Zirconium disulfide forms organometaUic intercalations with a series of low ionization (<6.2 eV)-sandwich compounds with parallel rings (143). 

It should be observed that every element except the powder system in the recovery system is chosen for favorable shock properties which can be confidently simulated numerically. The precise sample assembly procedures assure that the conditions calculated in the numerical simulations are actually achieved in the experiments. The influence of various powder compacts in influencing the shock pressure and mean-bulk temperature must be determined in computer experiments in which various material descriptions are used. Fortunately, the large porosity (densities from 35% to 75% of solid density) leads to a great simplification in that the various porous samples respond in the same manner due to the radial loading introduced from the porous inclusion in the copper capsule. 

Interactions at surfaces and interfaces also play an essential role in the design and function of clinical implants and biomedical devices. With a few recent exceptions, implants do not attach well to tissue, and the resulting mobility of the tissue-implant interface encourages chroitic inflammation. The result can be a gathering of platelets at the site, leading to a blood clot or to the formation of a fibrous capsule, or scar, around the implant (Figure 3.3). 

Fig. 27 Rotary die machine. (A) Ribbon casting drum (B) ribbon (C) filling leads (D) injection mechanism (E) rotary die (F) capsule wash (G) infrared dryer. (Courtesy of R. P. Scherer North America, Clearwater, FL.)... 

FDA. 1996. Tin-coated lead foil capsules for wine bottles. U. S. Food and Drug Administration. Code of Federal Regulations. 21 CFR 189.301. 

The self-heating and decomposition of the explosive and aqueous alkali was studied by DSC in a sealed capsule and in a larger scale furnace test. A rapid exothermic decomposition reaction can be initiated at 100°C or below, and may lead to spontaneous ignition and then deflagration or detonation. 

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