Content: In today’s business environment, organisations are increasingly reporting their sustainability credentials through different channels. However, in a traditional industry with a complex supply chain as leather, many companies do not publicly disclose details of their sustainability activities, while a considerable number of companies report on the environmental sustainability aspect alone. Hence, this study identifies good practices of sustainability reporting, discussing the sustainability information extracted from the reports of a selected number of companies in the leather industry. A thematic content analysis was used to extract sustainability information from either the website, annual report, sustainability report or corporate social responsibility report of six leather companies. A review of existing literature assisted in categorising different practices under the three sustainability dimensions while a highlight of patterns among practices followed. The results show that the companies are observing a good practice of either dedicating a section of their website to revealing their sustainability activities or utilising their sustainability reports. Additionally, these companies follow a good practice of reporting their activities based on the economic, social and environmental sustainability dimensions, rather than focusing on just one of the aspects. Amongst the six companies, energy efficiency and reduction in greenhouse gases emission were the most occurring environmental sustainability practices. On the other hand, health and safety occurred as the dominant social sustainability practice of the leather industry, while economic sustainability practices have not been well defined, providing an opportunity for future research. Conclusively, the study provides a useful resource for managers and companies in the leather industry to learn from brands that have been embarking on sustainability efforts and assist them in getting a grasp of the concept, in readiness for strategy formulation, implementation and reporting. This study provides knowledge of the sustainability criteria to be met by small, medium sized and large leather supply chain actors on their sustainability journey. Take-Away: 1. The companies are observing a good practice of either dedicating a section of their website to revealing their sustainability activities or utilising their sustainability reports. 2. The companies also follow a good practice of reporting their activities based on the economic, social and environmental sustainability dimensions, rather than focusing on just one of the aspects. 3. Energy efficiency and reduction in greenhouse gases emission were the most popular environmental sustainability practices, health and safety was the dominant social sustainability practice while economic sustainability practices have not been well defined.

Content: The purpose of this paper is to study the influence of acrylic resins on the properties of the hide when added in the pickling-tanning stage of a wet white process. Among retanning products, acrylic resins are very frequently used because they lend very good properties to the hide on account of their high affinity for chromium. When applied during chrome tanning, these resins provide the hides with high fullness, due to the strong interaction of the carboxylate groups with chromium. Extensive bibliography is available on the application of acrylic resins in wet blue, where it is observed that the properties they provide to the hides depend basically on the type of monomers and molecular weight. However, less information is found when these products are applied in wet white tanning. In this study, 9 resins with different molecular weights and different monomer compositions were selected. Resins were applied to pelt leathers of Spanish origin split at 3.5 mm. Hides were cut along the backbone. A standard process was applied to the left halves and the same process adding the resin was applied to the right halves. The resin was added after adjusting the salt of the bath and before adding the pickling acids. The COD was measured before and after adding formic and sulfuric acid, and the shrinkage temperature and the degree of whiteness of the tanned hide were assessed. Hides were retanned and fatliquored with a standard process, and degree of softness, thickness, color intensity and organoleptic properties (fluffiness, compactness and grain tightness) were assessed. Leather shrinkage under temperature was also assessed, and images of leather sections were obtained by scanning electron microscopy (SEM). While acrylic resins did not increase shrinkage temperature, they did fix and/or deposit themselves in the interfibrillary spaces of the hide; indeed, highly reduced COD values after acidification in the pickling stage were observed. This study shows that homopolymeric acrylic resins provided fuller and fluffier hides, while the rest of resins practically did not improve the physical and organoleptic properties of the hides. Take-Away: Homopolymeric acrylic resins provided full er and fluffier hides, while the rest of resins practically did not improve the physical and organoleptic properties of the hides Wet white tanning improvement

Content: Nanoparticles showed a huge potential for new properties development in many economic sectors like electronics, medicine, textile, waste water treatment etc. The modification of surface functionality by using low concentrations of nanomaterials opens the possibility of lowering the ecological impact of chemical materials based on volatile organic compounds. The objectives of our research were related to the use of commercial nanoparticles based on Ag and TiO2 with average particle size of 8 nm for leather surface functionalization and the investigation of the cytotoxicological impact of nanoparticle concentrations on human skin cells. The practical implications of the approach consist of multifunctional leather surface development, leather durability and comfort increase by generating antimicrobial and self-cleaning properties. The relation between leather functionality and the cytotoxicity concentration limit of nanomaterials was the hypothesis of our research. The main procedures for leather surface covering followed the classical recipes based on surface spraying with film forming composites with nanoparticle content. The optimized technology was evaluated by leather surface analyses regarding the antimicrobial (SR EN ISO 20645) and self-cleaning properties under UV and visible light exposure as compared to leather surface covered without nanoparticles. The cytotoxicity tests were performed by incubation of keratinocytes (Human immortalized keratinocytes-HaCaT) with different concentrations of nanoparticles for 48 hours and measurement of cell viability by MTT (3-[4,5-dimethylthiazol- 2-yl]-2,5-diphenyltetrazolium bromide) assay protocol. Other tests were devoted to leather wearing simulation in order to estimate the potential transfer of nanoparticles on human skin and the health and safety impact. These simulations were based on rubbing test (SR EN ISO 11640) followed by scanning electron microscopy with energy dispersive X-ray spectroscopy (SEM/EDX) analyses and by leachability tests (SR EN ISO 4098) performed in artificial perspiration solution followed by inductively coupled plasma -mass spectrometry (ICP-MS) analyses, according to SR EN ISO 17294-2 and SR EN ISO 16171. The main conclusions of our research showed that it is possible to add multifunctional value to leather surface by using Ag and TiO2 nanoparticles with low impact on safety and health. Acknowledgements: The works were funded by UEFISCDI and MCI, project number PNIII_15/2015-2018 under the frame of SIINN, the ERA-NET for a Safe Implementation of Innovative Nanoscience and Nanotechnology program and respectively, PN 19 XX 05 01 project/2019 under Nucleus program TEX-PELVISION 2022 Take-Away: - antimicrobial and self-cleanning nanoparticles for leather surface finishing - Ag and TiO2 nanoparticle cytotoxicity tests for human skin cells - multifunctional surface properties with low cytotoxicological impact

Content: A novel class of bio-based polymers have been developed within the LIFE BIOPOL European project aiming to replace traditional re-tanning and fat-liquoring products reducing environmental impacts and increasing the safety of leather. The purpose of the project is to enhance the recovery and reuse of different bio-derived by-products from leather and agro-industrial sector to produce eco-friendly and renewable bio-polymers with high re-tanning and fat-liquoring characteristics. The LIFE BIOPOL project aims to make bio-based polymers in order to reduce the following parameters in re-tanning phase: - 20-30% COD, - 50-60% of inorganic salts (Sulphates and Chlorides), - 90% of Cr (III) salts, - 20% of water used in the leather process. Other important goals of the project are: - reduction 70-90% of hazardous and environmental polluting substances normally found in conventional chemicals, - reactivity enhancement of 30-40% of the new biopolymers compared to the current leather - application technology, - reduction of 70-80% of the Product Environmental Footprint of the new biopolymers related to the state of the art. The vegetal biomasses and the tanned hides by-products were pretreated in order to obtain suitable building blocks for the production of bio-based polymers. Several protocols involving polymerization were used in order to achieve the synthesis of the biopolymers, which have been carried out at lab scale. Macromolecular characterization of the biopolymers was performed in order to rationalize the synthetic strategy and practical application of the products giving important parameters such as molecular weight and chemical composition of the new biopolymers. Performances of new bio-based polymers have been inspected and compared with traditional chemicals through application on different types of leather. The benefits of the new products within leather making process were evaluated through chemical analyses of re-tanning and fat-liquoring effluents. The upgrade of the developed chemistry will be performed within a new devised prototype plant specifically designed and built-up for producing the bio-based polymers at industrial scale Take-Away: Production of leather making biopolymers from biomasses and industrial by-products through Life Cycle Designed Processes

Content: Acrylic resin (AR) is a most popular retanning agent due to its selective filling property and advantage of formaldehyde-free. The retanning performance of acrylic resin mainly depends on its penetration depth and filling parts in leather. Therefore, to improve the retanning performance, it is necessary to fully understand the factors affecting the mass transfer and the distribution of acrylic resin in leather. We have found that the structure and the charge of leather and the dosage of acrylic resin rather than the molecular weight of acrylic resin are important factors affecting the penetration rate of acrylic resin in crust leather by using fluorescent tracer technique. In this study, from the view of electrostatic interaction, effects of neutralizing pH and retanning auxiliaries such as phenol sulfonic acid condensation (PSAC) and sodium carboxymethylcellulose (CMC) on the penetration and the distribution of acrylic resin in crust leather were investigated. Higher neutralizing pH led to a faster transfer of acrylic resin in leather because of the decrease in the positive charges of chrome-tanned leather (isoelectric point 7.1) and the increase in the negative charges of acrylic resin. Employing PSAC and CMC enhanced acrylic resin transfer in crust leather due to the dramatic increase in the negative charges of acrylic resin. These results indicated that decreasing the electrostatic binding force between acrylic resin and crust leather is beneficial to the penetration of acrylic resin in leather, which could be achieved by adjusting the neutralizing pH or using acrylic resin together with proper retanning auxiliaries. Take-Away: 1. Using phenol sulfonic acid condensation and sodium carboxymethylcellulose enhanced acrylic resin transfer in crust leather. 2. Decreasing electrostatic binding force between acrylic resin and crust leather is beneficial to penetration of acrylic resin in leather. 3. Increasing neutralizing pH or using proper retanning auxiliaries can decrease the electrostatic interaction between acrylic resin and crust leather effectively.

Content: Product Environmental Footprint Category Rules (PEFCRs) for calculating the environmental impact of leather manufacturing were approved by the European Commission in 2018. Chemicals are key input data for this methodology, given leather’s chemically intensive makeup. The increasing use of nonpetrochemical materials represents an important part of industry-wide efforts to reduce overall environmental impact. Though still in its infancy, research and commercial use of renewable raw materials for leather chemicals is expected to accelerate in the coming years, especially with regard to understanding the environmental impact of bio-based products. Indeed, when decisions are made to substitute fossil fuel-derived products with alternative bio-based versions, a common assumption is that a reduction in environmental footprint will accompany that substitution. However, reports have been published that challenge this view1,2,3. The aim of this paper is to provide an overview of environmental impact data for bio-based polyurethanes and to interpret the data in order to make better decisions about further research and product design. Take-Away: Environmental impact is not just about Climate Change

Content: Today, automotive leather has to meet a multitude of requirements for different automotive brands. In addition to the important traditional aesthetic properties, such as the feel and appearance of the leather, a growing number of measurable specification parameters have been added over time. One of these parameters are the Volatile Organic Compounds (VOC) which the final leather article emits. The large number of emission specifications, each with its own limits, represents a major challenge in the development of automotive leather today. Each of these methods has a slightly different substance focus and highlights certain groups of volatile substances in the test result. This often makes a targeted development for a certain leather article with associated test method necessary. The recurring question of how to further reduce the emissions of automotive leather is answered by presenting the latest developments from the Leverkusen laboratories as one focus of this work. The increasingly profound measurement of the emissions over the last decades has led to VOCs becoming reduced from grams to micrograms per kilogram of leather. Most probably because of this dramatic reduction in VOC levels, the focus of the regulations has switched today more from quantity of emissions to the properties of single substances emitted. Often the exact source of these substances were initially unknown and consequently a specific solution to meet the limits were not available. The search for the sources is becoming increasingly complex and difficult as many of these substances are not applied directly but are often degradation products of other compounds. Often the measured low concentrations are in the range of the natural decomposition processes. Nevertheless, it is possible to identify some of the sources by evaluating the results of different analytical methods. Thus it is now possible to develop suitable countermeasures. The presentation of the source of special single volatile organic substances as well as their reduction forms a further focus of this work. Take-Away: Reduction of Emissions Finding sources of substances emitted from leather Presenting countermeasures to reduce those substances

Content: Leather industry is one of many traditional, characteristic and ascendant industries. During the development of Leather industry, the problem of a certain the waste of resources and environmental pollution has been yielded. The waste tallow is one of the problems should be solved quickly. Based on the problem of the waste of resources and environmental pollution form the waste tallow during the leather industry, act waste beef tallow from tannery as raw material, detection of its physical and chemical properties, de-colorization, deodorization, amidation, esterification and sulfitation were done successively. Results suggested that the acid value and the saponification value of the waste beef tallow is 45mgKOH/g, 207mgKOH/g respectively. When 6% activated clay was used after 10% hydrogen peroxide, it has the best effect in decolorization and deodorization. When catalyzed by 1% sodium formate, n（ethanolamine）：n （waste beef tallow）is 4:1，the reaction temperature was 130~140oC and time was 2hrs, the acid value and hydroxyl value of the treated beef tallow is 15~30mgKOH/g, about 280mgKOH/g respectively. When the optimum dosage of sodium sulfite is 20%, the fatliquor obtained light yellow and good stability. The sheepskin garment leather fatliquored by this fatliquor is very soft. Take-Away: Modification of a sulfited fatliquor based on waste beef tallow. Application of this sulfited fatliquor. Other methods of modification of waste beef tallow.

Content: A combination of processing techniques and speciality chemicals has been developed to target environmental issues and legislation in the European leather industry, especially for automotive upholstery leather. This process combines new techniques in the beamhouse process through to the tanning process. Initial work on several different individual concepts showed some excellent improvements, but when these concepts have been brought together to form a single strategic process the advantages and improvements have exceeded expectations. The process demonstrates a reduction in the use of salt, formic acid and sulphuric acid. After more than two years of trials from small scale to full production in an automotive leather production environment, we are able to present independently test results showing the benefits of following this system. Briefly these include Improvement in tear and tensile strength results. Improved clarification with less suspended solids in the supernatant. Reduced COD in the supernatant and higher biodegradability COD/BOD. Less TDS in the supernatant. Chloride content reduction in the supernatant Sludge generation reduction. Less organic residues derived from the hide. Take-Away: A simple technique and small modifications to existing processing methods will reduce dramatically the environmental effects of wet white / chrome free tanning. This process can be used in any country in the world and answers many questions regarding reducing salt, BOD, COD, TDS etc.

Content: The research on Collagen that possesses unique fibre structure are reported frequently. In this paper, the cross image of leather fibre of dried wet blue cowhide embedded with and without epoxy resin were investigated with micro computed topography(MCT). The images obtained by MCT of leather fibre are original status without any damage, while the embedded leather can emerge distortion because the fibre was fixed during the solidifying and immersing of the resin. In this research, 2357 images of leather fibre were investigated on wet blue leather(original fibre) and the same piece of leather embedded by epoxy resin(embedded fibre). The area ratio of the sections from the original fibre and the embedded fibre was examined for each image. The statistic results showed that the mode of area ratio of the original fibre section to the entire fibre section is 75%, and the mode of area ratio of the embedded fibre section to the embedded fibre entire section is only 48%. The mode of the area ratio of the original fibre is obviously higher than the mode of the area ratio of the embedded fibre, that is diverse with the anticipation of fibre swelling caused by resin. The reason might be the expansion of interval space among the fibre filled with epoxy resin, otherwise the conglutination of fibre caused by the evaporation of solvent(acetone used in embedding) in the course of the resion solidifying. Likewise, it can be the adhesion of the tiny fibre with the larger fibre that will diminish the area caculated. The factors will be studied further on embedding to achieve a method with minimum deformation on cross image of fibre. Take-Away: The area ratio of cross section on embedded fibre shrunk comparing with the original fibre, that is out of anticipation of the probable swelling created by resin.