Leather tanners

Louis Pasteur [1822-18951 was born at Dole in the Jura region of France, the son of leather tanners. After receiving his doctorate from the Ecole Wormale Superieure at age 25, his landmark discovery of tartaric acid... 

Levine SM, Baker DB, Langrigan PJ, et al Testicular cancer in leather tanners exposed to dimethylformamide (Letter). Lancet 2 1153, 1987... 

Many dietary and environmental factors have been implicated as possible etiologic factors in the development of pancreatic cancer, but no definite causal relationships have been established. The strongest evidence points to cigarette smoking as a risk factor associated with pancreatic cancer (20-24). Occupational exposure to certain chemicals has also been linked to pancreatic carcinoma (25). Others in the high-risk group include stone miners, cement workers, gardeners, textile workers, and leather tanners (17,26). 

Mikoczy, Z., Schutz, A. Hagman, L. (1994) Cancer incidence and mortality among Swedish leather tanners. Occup. environ. Med., 51, 530-535... 

Studies of chromate production workers, who are exposed to a variety of chromium compounds both hexavalent and trivalent, and chromate pigment industries, where exposure is mainly to chromium(VI), have consistently demonstrated an association with respiratory system cancer. Studies in chrome platers, who are exposed to chromium(VI) and other agents, including nickel, generally support the conclusion that certain chromium(VI) compounds are carcinogenic. Studies in stainless steel welders exposed to chromium(VI) and other chemicals, and in ferrochromium alloy workers, who are exposed mainly to chromium(O) and chromium(III), but also to some chromium(VI), were inconclusive. Studies in leather tanners, who are exposed to chromium(III), were consistently negative. 

An early report of cases of chrome ulcers in leather tanners noted that the only workmen in tanneries who suffered chrome holes were those who handled dichromate salts. In one of these cases, the penetration extended into the joint, requiring amputation of the finger (Da Costa et al. 1916). In a medical survey of... 

The skin and nails of electroplaters, leather tanners, lithographers and others who contact bichromate assume a pale ochre yellow tint (White i934a,b). 

The total volume of pinesite hardwoods is about 54 billion cu. ft. and half of them are oaks. These hardwoods are harvested along with the pines. Oak bark is known to be rich in tannin and was used extensively by leather tanners in pioneer days. 

Tanning of hides by any of the primitive methods was a dirty job withHttle assurance of success. The tanner was a speciaUst generating little respect in the community. In some parts of the world, this ancient prejudice against tanners exists even as of this writing (ca 1994). The tanner in primitive societies was limited to making leather using the hides or skins available locally. Tanning materials were also limited to those in local supply. Techniques were dependent on the climate as well as avadabihty of materials. The leather made was for local needs. 

The usual procedure in the manufacture of chrome-tanned leathers is the use of a continuous bate, pickle, and tan method. The hides or skins remain in the dmm from the lime washing through the chrome tanning stages. The entire process usually takes about 22—24 hours. The bate, pickle, and tan can be done faster, but most tanners find that a one-day cycle fits well into production scheduling and results in a quaUty leather. 

Gerber-fett, n. (Leather) d gras, stuff, -hof, m. tan yard, -kalk, m. slaked lime gas lime, -lobe, /. tanbark tan liquor, -strauch, m. tanner s sumac (Rhus coriaria) ink plant (Coriaria). -wolle, /. skin wool, pelt wool. 

The use of enzymes for the manufacture of leather played a major role for the industrial scale production of enzymes. For the preparation of hides and skins for tanning, the early tanners kept the dehaired skins in a warm suspension of the dungs of dogs of birds. Wood was the first in 1898 to show that the bating action of the unpleasant dungs was caused by the enzymes (pepsin, trypsin, lipase) which they contained. In the context... 

It is employed by the natives of North-wcstom India for precipitating their indigo, and in tanning. English tanners, however, object to its use on account of the disagreeable color it communicates to the leather. 

Preparation op the Hides.—The tanner, previous to submitting the hides, skins, or kips, to the true tanning process, is under the necessity of subjecting them to one or more preliminary operations, with the view of removing dirt, particles of flesh, and in most cases tho hair and epidermis and the manner in which these are effected is of great importance, as mueh of the success of the subsequent process, and, consequently, of the quality of the leather, depends upon it. 

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