Lead poisoning in potteries, tile works, and porcelain enameled sanitary ware factories ...

  • Alice Hamilton
Date:
1912
Catalogue details

Licence: Public Domain Mark

Credit: Lead poisoning in potteries, tile works, and porcelain enameled sanitary ware factories ... Source: Wellcome Collection.

Provider: This material has been provided by the Augustus C. Long Health Sciences Library at Columbia University and Columbia University Libraries/Information Services, through the Medical Heritage Library. The original may be consulted at the the Augustus C. Long Health Sciences Library at Columbia University and Columbia University.

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    disilieate (Pb02SiO.) can not be formed in enamels for the simple reason that there is not enough silica to go around. In fact, Thorpe's statement holds quite accurately. The question as to what actually happens in this fusion process and what forms of lead exist in the so-called frit has been gone into very thoroughly in the Thorpe- Oliver report to Parliament,1 which defines fritted glazes as those in which the whole of the lead has been fritted as a properly com- pounded lead silicate—that is, fritted directly with the other com- ponents of the glaze so as to form a double silicate. * * * Experi- ment shows, however, that much depends upon the nature and com- position of the fritted lead. * * * The ordinary silicate, containing about 70 per cent lead oxide, 25 per cent silica, with small quantities of alumina, lime, magnesia, and alkalies, corresponding in fact to a crude monosilicate, and which is generally understood as fritted lead, is hardly less soluble in acids than basic lead car- bonate [white lead]. That the fritting process in use in the sanitary ware establishments in the United States does not render the lead insoluble is shown by the following analyses of samples of enamel mixtures made for this report by the Bureau of Chemistry, Department of Agriculture. Isos. G and 7 are from the same factory. PER CENT OF SOLUBLE LEAD TN SEVEN SAMPLES OF ENAMEL MIXTURES. Sample No. 1. Sample No. 2. Sample No. 3. Sample No. 4. Sample No. 5. Sample No. 6. Sample No. 7. Per cent soluble lead (PbO) when exposed to the action of 0.25 per cent hydrochloric acid for 2 hours (Thorpe test). 9.04 2.55 6.31 8.35 20.4 0.51 10.22 MIXING OF THE ENAMEL. According to our present knowledge of these enamels we may say that in grinding, sifting, and applying the enamel, the workmen are exposed to a dust which contains lead in soluble form, soluble, that is, in the gastric juice, and probably also in the saliva and the mucus of the respiratory tract, and in mixing the ingredients for the enamel the workmen must handle the oxides of lead, which are by many authorities considered as among the most dangerous of lead com- pounds, and by some as the most dangerous of all because of their lightness and dustiness. Mixing is always clone in rooms quite separate from the enameling. The materials which are used, including the lead oxide, are stored in bins or barrels and handled with shovels. In a well-equipped mixing room these ingredients fall through a chute from the storage room 1 Report on the Employment of Compounds of Lead in the Manufacture of Pottery, by T. E. Thorpe and Thomas Oliver, p. 10. Home Office, London, 1899. 558S40—12 3