Tirrena S.P.A. Tannery bases its philosophy on clear and essential concepts, which summarize the commitment and passion employed over more than 60 years: search for raw materials, prestige of materials, product excellence, customer satisfaction. Quality control in the laboratory is based on these principles, which includes an evaluation of resistance to mechanical stress, a measurement of color fastness to external agents, and a determination of chemical parameters in correlation with consumer health and safety requirements.

1 – VISUAL INSPECTION

Visual Inspection involves verifying that the hides meet the standards of color, thickness, and all fundamental visual characteristics to be suitable for shipment. This phase serves to test the main structural characteristics of the leather as well as to evaluate and improve various production processes.

2 – MECHANICAL INSPECTION

Mechanical inspection involves a series of sample checks which, depending on the situations, use different techniques. Tests for the physical-mechanical characterization of leather for uppers and linings:

–  Thickness measurements

– Water absorption measurements

– Shrinkage temperature measurements

– Tear resistance determination

– Breaking load determination and percentage elongation

– Determination of resistance to repeated bending

– Determination of water vapor permeability

– Determination of abrasion resistance

– Determination of seam strength

– Determination of water absorption/desorption

– Determination of dynamic impermeability

– Color fastness to perspiration

– Color fastness to rubbing

– Color fastness to water drops

3 – CHEMICAL INSPECTION

Every batch of goods marketed by Conceria Tirrena S.p.A. is tested multiple times both upstream and downstream of the tanning process to ensure compliance with the latest REACH regulations.Regulation (EC) No. 1907/2006, known as REACH, is an integrated regulation for the registration, evaluation, and authorization of chemicals, aimed at ensuring a higher level of protection for human health and the environment, while at the same time aiming to maintain and strengthen the competitiveness and innovative capacity of the European chemical industry.Definitions (REACh-Dir. 67/548 EEC)

Chemical substances:These are chemical elements and their compounds, in their natural state or obtained by any production process, containing the additives necessary to preserve the stability of the product and the impurities resulting from the process used, excluding solvents that can be separated without affecting the stability of the substance and without altering its composition.Some substances may be present because they are normally used in the production cycle or used for the production of leather in countries where there are no usage restrictions. Their concentration in the final product must therefore be lower than the limit prescribed by law. It is therefore necessary to distinguish between prohibited substances and substances permitted but subject to limitations.

Which substances are subject to restrictions in leather? All those recognized as extremely harmful to human health, for example: toxic, carcinogenic, hazardous to the environment. While previously only manufacturers (provided they introduced the substance into the European market) and importers of new chemical substances had to undertake the complex substance notification procedures, today they are involved in the important processes of the Regulation: producers of substances not placed on the market; producers and importers of existing substances; downstream users of chemical substances.

AZO DYES

What are they? Azo dyes contain various types of azo groups (-N=N-) linked to aromatic groups. There are several hundred azo dyes, but only those that degrade to produce prohibited aromatic amines are subject to restriction (in fact, it is a type of indirect restriction). Aromatic amines are a type of chemical substance generated mainly in the production of dyes and coloring pigments for fabrics, leather, paper, and the rubber industry. The most important aromatic amines include, among others, benzidine, 4-aminobiphenyl, 2-naphthylamine, and ortho-toluidine.

Where are they found? They can be present in dyes as well as in tinters.

Cause of Restriction: Some azo dyes can degrade to form prohibited amines

Regulatory Reference: In Europe, Directive 27-7-1976 No. 76/769/EEC XIX amendment – Azo dyes (Directive 2002/61/EC) Appendix 8 point 43 REACH AII XVII substances subject to restriction. Prohibition of placing on the market of azo dyes that can form prohibited aromatic amines. In Italy, UNI 10594 – Characteristics and requirements of hides for the footwear industry. UNI 10826 – Characteristics and requirements of hides for the leather goods industry.

Which Method? EN ISO 17234. The ISO method is the result of a European research project dedicated to improving the repeatability and reproducibility of the analysis, which has always been problematic.

Limit: < 30 mg/kg with EN ISO 17234 method

PENTACHLOROPHENOL (PCP) AND CHLOROPHENOLS (TRI- AND TETRACHLOROPHENOL)

What are they? Chlorophenols are chlorinated organic compounds used as preservatives for hides.

Where are they found? They are used as mildew inhibitors in textiles, hides, and some wood products.

Cause of Restriction: PCP is a persistent substance in the environment, it can have effects on human health and is toxic to the aquatic environment, furthermore, the combustion products of pentachlorophenol can be toxic.

Regulatory Reference: In Europe: it cannot be used in concentrations exceeding 0.5% mg/kg (sum) in substances or preparations placed on the market. In Italy UNI 10594 – Characteristics and requirements of hides for the footwear industry. UNI 10826 – Characteristics and requirements of hides for the leather goods industry.

Limit: 0.5% mg/kg (sum) < 5 mg/kg with method: EN ISO 17070:2007

HEXAVALENT CHROMIUM (Chromium VI)

What is it? Chromium is a metal that can occur as a salt in metallic or oxidized form (III) and (VI). The restriction concerns only the (VI) form. Chromium (VI) is not normally present in hides.

Where is it found? Chromium (VI) salts can be present in pigments or as additives in dyes or fixatives. In some cases, depending on the pH and in the presence of particular substances (greases), it can be formed in the hide by oxidation of chromium (III).

Cause of Restriction: Chromium (VI) and its salts are considered carcinogenic.

Regulatory Reference: In Germany Eighteenth amendment to the LBGV, August 3, 2010. In Italy: UNI 10594 – Characteristics and requirements of hides for the footwear industry. UNI 10826 – Characteristics and requirements of hides for the leather goods industry.

Limit: < 3 mg/kg with EN ISO 17075 method

FORMALDEHYDE

What is it? Formaldehyde is an organic compound widely used as a preservative (formalin) and mildew inhibitor.

Where is it found? It can be used as a printing fixative for fabrics, as a component for glues and adhesives, and as a preservative for varnishes and lacquers. It is also present in wood panels (such as masonite or plywood). In the tanning process, it can be found as a substance for the reticulation of casein, in resins; it is often found as a by-product (and therefore as “trimmings”) in synthetic tannins. Formaldehyde can be used, provided it is used under safe conditions. The restriction concerns free formaldehyde (which can be released) and not bound formaldehyde.

Cause of Restriction: Formaldehyde is irritating to the eyes and skin. It is considered a potential mutagen and carcinogen for the eyes, nose, and lungs, although there are not enough studies to support it.

Regulatory Reference: In Germany Chemicals Prohibition Ordinance – May 2003; Poland, Finland, Norway, France, Netherlands, Austria, Lithuania.

In Italy: UNI 10594 – Characteristics and requirements of hides for the footwear industry. UNI 10826 – Characteristics and requirements of hides for the leather goods industry.

Limits: 75 mg/kg

Which Method? It is preferred to refer to the EN ISO 17226-1 (colorimetric) and EN ISO 17226-2 (HPLC) methods, to promote a culture of internationally relevant standardization, avoiding references to national standards that are often outdated.