Leather articles

Most of the commercially available azo dyes do not break down to produce these forbidden amines. The European legislation which states that leather articles that come into contact with human skin should not contain any of the 22 aromatic amines in concentrations above 30 ppm can be found in Annex XVII [12] of REACH. Furthermore, most eco-labels and RSL have the same criteria. 

To protect human health and improve consumer safety, the European Parliament and the Council of the European Union (EU) pubhshed Directives 2002/61/EC and 2003/3/EC on September 11, 2002 and January 6, 2003, respectively. These restrict the use of carcinogenic azo-dyes in textiles and leather articles and prohibits the sale of such articles dyed with the restricted azo dyes. Directives 2002/61/EC and 2003/3/EC had been transposed into national laws and put into effect in the member states respectively by September 11,2003 and June 30,2004. Aromatic amines (azo dyes) (22 kinds) specified and prohibited by Directive 2002/ 61/EC are listed in Table 3.3. 

Azo dyes which, by reductive cleavage of one or more azo groups, may release one or more of the aromatic amines listed in the Appendix in detectable concentrations, i.e. above 30 ppm in the finished articles or in the dyed parts thereof, may not be placed on the market or used in textile and leather articles which may come into direct and prolonged contact with the human skin or oral cavity, such as... 

Furthermore, the textile and leather articles referred to in point 1 above may not be placed on the market unless they conform to the requirements set out in that point. 

Azo dyes which are contained in the list of azo dyes that is added to the Appendix may not be placed on the market or used for coloring textile and leather articles as a substance or a constituent of preparations in concentrations higher than 0.1% by weight. 

PROTECTION OF LEATHER AND LEATHER ARTICLES AGAINST BIODAMAGES... 

Non-occupational relevance is given in foot dermatitis elicited by shoes, in wrist dermatitis by watch straps and in other leather articles (Freeman 1997). Nine of 839 Finnish patients patch tested with a glue series reacted to PTBP-FR, which turned out to be the most common relevant glue allergen (Tarvainen 1995). 

MDA should never be allowed to remain on the skin. Clothing and shoes which are not impervious to MDA should not be allowed to become contaminated with MDA, and if they do, the clothing and shoes should be promptly removed and decontaminated. The clothing should be laundered to remove MDA or discarded. Once MDA penetrates shoes or other leather articles, they should not be worn again. 

To determine the method used in mineral-tanned leathers, it is necessary to test the sample for certain inorganic compounds. The most common mineral tanning compounds are chromium salts sometimes aluminum salts are used, more rarely, iron salts. They may also be used in combination. Spot tests can be used for the detection of these inorganic tanning agents. The sample required is so small that it may be taken from manufactured products (shoes, small leather articles) without visible damage. 

Annex 1, No. 7 of the German Consumer Goods Ordinance, last amended 13 July 2005 [26] had unexpected repercussions in certain azo pigments. This entry banned the use of azo dyes which, on cleavage of one or more azo bonds would form any one of 22 Usted aromatic amines (see Table 23.6) in textiles and leather articles intended for more than temporary contact with the skin. The basis for the restriction is, that the restricted dyes are possible carcinogens, which is supported by the available test data. 

Leather articles Vinyl chloride Vinyl acetate... 

In wet finishing, the character of the leather article (softness, strength, water re-peUency) is substantially determined by the retanning and the fat-liquoring operations. The leather is also dyed. This is done using soluble dyes. 

The various leather articles with their specific requirements each require a specific optimized process in the tannery. Classifying leather finishes according to, say, the binders used or the method of application, the appearance or the ready-produced leather article is thus possible only to a limited extent. Frequently there are many different ways of producing the desired article. Leather finishing is therefore regarded as being more an art than a science. 

Metallized dyes, for example, are used to dye, or correct the hue of the surface of leathers which have not been drum dyed and to match it to the hue of the finish. As a result, damages to the finish in the course of the use of the leather article are less pronounced. 

Depending on the cmst leather used, the adhesion of the finish layer to the leather has to be improved in some cases by means of a separate base coat. Adequate adhesion is the precondition for many application properties and important to achieve the required physical fastnesses for the ready-produced leather articles. Soft, finely divided polyurethane dispersions have won out in this sector over polyacrylate dispersions. 

Guideline recipes for finishes for some selected leather articles will now be used by way of example to discuss the particular requirements that have to be met by the polymer dispersions used. The finisher has to adapt these guideline recipes to the leather to be finished and to the final properties demanded (feel, appearance, fastness). 

Since finished leathers are predominantly used in the shoe industry, test methods are largely adapted to these requirements. From experience, these test methods are also suitable for evaluating other leather articles such as upholstery leather, apparel leather and leather for bags and suitcases. The fastness level to be achieved varies from article to article. 

The following methods are only the most important tests in common use. In addition, there are a multiplicity of specific test methods, either designed for certain leather articles or required by certain customers. 

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