{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,5,17]],"date-time":"2026-05-17T10:03:45Z","timestamp":1779012225244,"version":"3.51.4"},"reference-count":50,"publisher":"MDPI AG","issue":"8","license":[{"start":{"date-parts":[[2025,4,18]],"date-time":"2025-04-18T00:00:00Z","timestamp":1744934400000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"name":"Lineapelle s.r.l.","award":["1551.11-10-2022"],"award-info":[{"award-number":["1551.11-10-2022"]}]},{"name":"Lineapelle s.r.l.","award":["PE00000004"],"award-info":[{"award-number":["PE00000004"]}]},{"name":"PON \u201cRicerca e Innovazione\u201d 2014\u20132020","award":["1551.11-10-2022"],"award-info":[{"award-number":["1551.11-10-2022"]}]},{"name":"PON \u201cRicerca e Innovazione\u201d 2014\u20132020","award":["PE00000004"],"award-info":[{"award-number":["PE00000004"]}]},{"name":"Asse IV \u201cIstruzione e Ricerca per il recupero\u201d Azione IV.5 \u201cDottorati su tematiche green\u201d","award":["1551.11-10-2022"],"award-info":[{"award-number":["1551.11-10-2022"]}]},{"name":"Asse IV \u201cIstruzione e Ricerca per il recupero\u201d Azione IV.5 \u201cDottorati su tematiche green\u201d","award":["PE00000004"],"award-info":[{"award-number":["PE00000004"]}]},{"name":"MICS (Made in Italy Circolare e Sostenibile)","award":["1551.11-10-2022"],"award-info":[{"award-number":["1551.11-10-2022"]}]},{"name":"MICS (Made in Italy Circolare e Sostenibile)","award":["PE00000004"],"award-info":[{"award-number":["PE00000004"]}]},{"name":"European Union\u2014NextGenerationEU","award":["1551.11-10-2022"],"award-info":[{"award-number":["1551.11-10-2022"]}]},{"name":"European Union\u2014NextGenerationEU","award":["PE00000004"],"award-info":[{"award-number":["PE00000004"]}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Materials"],"abstract":"<jats:p>The tanning of hides is a practice deeply rooted in ancient times, but in the early 20th century, transitioning to an industrial model of leather and hide production, chrome tanning expanded globally due to its practicality, quality, and versatility. However, in recent decades, there has been a growing attention paid to the potential oxidation of the free chromium present in tanned leather, which could transform from an unharmful trivalent status into its carcinogenic hexavalent status. This phenomenon occurs in a very small fraction of hides, which is yet sufficient to exhibit significant activity. Hence, there is an evident need to explore further alternatives that allow avoiding oxidation. In this work, the performance of a sequence of selected antioxidants is evaluated in different oxidation conditions: simple stirring, UV\u2013Vis\u2013IR irradiation, and heating up to 75 \u00b0C. The official diphenylcarbazide\u2013UV tool norm was used to quantify the hexavalent chromium amount. The results underline the effectiveness of 2,6-di-tert-butylphenol, and that its greatest preventative method of addition during the tanning process is together with the tanning agent. This approach will pave the way for researching alternative concepts and exploring perspectives to inhibit chromium issues.<\/jats:p>","DOI":"10.3390\/ma18081858","type":"journal-article","created":{"date-parts":[[2025,4,18]],"date-time":"2025-04-18T06:23:56Z","timestamp":1744957436000},"page":"1858","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":2,"title":["Evaluation of Antioxidant Performance in Chromium Oxidation Prevention"],"prefix":"10.3390","volume":"18","author":[{"given":"Omar","family":"Salmi","sequence":"first","affiliation":[{"name":"Dipartimento di Chimica, Materiali e Ingegneria Chimica \u201cGiulio Natta\u201d, Politecnico di Milano, Piazza Leonardo da Vinci 32, 20133 Milano, Italy"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Giulia","family":"Laudisa","sequence":"additional","affiliation":[{"name":"Dipartimento di Chimica, Materiali e Ingegneria Chimica \u201cGiulio Natta\u201d, Politecnico di Milano, Piazza Leonardo da Vinci 32, 20133 Milano, Italy"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-2665-120X","authenticated-orcid":false,"given":"Filippo","family":"Rossi","sequence":"additional","affiliation":[{"name":"Dipartimento di Chimica, Materiali e Ingegneria Chimica \u201cGiulio Natta\u201d, Politecnico di Milano, Piazza Leonardo da Vinci 32, 20133 Milano, Italy"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-3457-4785","authenticated-orcid":false,"given":"Maurizio","family":"Masi","sequence":"additional","affiliation":[{"name":"Dipartimento di Chimica, Materiali e Ingegneria Chimica \u201cGiulio Natta\u201d, Politecnico di Milano, Piazza Leonardo da Vinci 32, 20133 Milano, Italy"}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"1968","published-online":{"date-parts":[[2025,4,18]]},"reference":[{"key":"ref_1","unstructured":"Razzaque, M.A., Eusuf, A., Uddin, M., and Rahman, J. (2020). Exports of Leather and Leather Goods: Performance, Prospects, and Policy Priorities. Navigating New Waters: Unleashing Bangladesh\u2019s Export Potential for Smooth LDC Graduation, Manchester Reasearch Explorer, Bangladesh Enterprise Institute."},{"key":"ref_2","first-page":"191","article-title":"The Determinants of Growth of Leather and Leather Products Manufacturing Micro and Small Scale Enterprises","volume":"7","author":"Hailemichael","year":"2015","journal-title":"Eur. J. Bus. Manag."},{"key":"ref_3","doi-asserted-by":"crossref","unstructured":"Limeneh, D.Y., Tesfaye, T., Ayele, M., Husien, N.M., Ferede, E., Haile, A., Mengie, W., Abuhay, A., Gelebo, G.G., and Gibril, M. (2022). A Comprehensive Review on Utilization of Slaughterhouse By-Product: Current Status and Prospect. Sustainability, 14.","DOI":"10.3390\/su14116469"},{"key":"ref_4","doi-asserted-by":"crossref","first-page":"590","DOI":"10.1016\/j.ijbiomac.2010.08.003","article-title":"Structure and dynamics of water in native and tanned collagen fibers: Effect of crosslinking","volume":"47","author":"Fathima","year":"2010","journal-title":"Int. J. Biol. Macromol."},{"key":"ref_5","doi-asserted-by":"crossref","unstructured":"Falc\u00e3o, L., and Ara\u00fajo, M. (2018). Vegetable Tannins Used in the Manufacture of Historic Leathers. Molecules, 23.","DOI":"10.3390\/molecules23051081"},{"key":"ref_6","doi-asserted-by":"crossref","first-page":"185","DOI":"10.1016\/S0921-3449(02)00151-9","article-title":"Sustaining tanning process through conservation, recovery and better utilization of chromium","volume":"38","author":"Sreeram","year":"2003","journal-title":"Resour. Conserv. Recycl."},{"key":"ref_7","doi-asserted-by":"crossref","first-page":"1143","DOI":"10.1016\/0043-1354(90)90178-9","article-title":"Effects of pH and oxidation state of chromium on the behavior of chromium in the activated sludge process","volume":"24","author":"Imai","year":"1990","journal-title":"Water Res."},{"key":"ref_8","doi-asserted-by":"crossref","first-page":"12489","DOI":"10.1021\/ic501603x","article-title":"Chemical Bonding in a Linear Chromium Metal String Complex","volume":"53","author":"Wu","year":"2014","journal-title":"Inorg. Chem."},{"key":"ref_9","doi-asserted-by":"crossref","first-page":"431","DOI":"10.3109\/10408449709078442","article-title":"Toxicity and Carcinogenicity of Cr(VI) in Animal Models and Humans","volume":"27","author":"Costa","year":"1997","journal-title":"Crit. Rev. Toxicol."},{"key":"ref_10","doi-asserted-by":"crossref","first-page":"89","DOI":"10.1002\/em.20525","article-title":"An evaluation of the mode of action framework for mutagenic carcinogens case study II: Chromium (VI)","volume":"51","author":"McCarroll","year":"2010","journal-title":"Environ. Mol. Mutagen."},{"key":"ref_11","doi-asserted-by":"crossref","first-page":"133","DOI":"10.1016\/j.cej.2005.09.017","article-title":"Surface properties of chemically modified activated carbons for adsorption rate of Cr (VI)","volume":"115","author":"Zhao","year":"2005","journal-title":"Chem. Eng. J."},{"key":"ref_12","doi-asserted-by":"crossref","first-page":"533","DOI":"10.1093\/carcin\/21.4.533","article-title":"Threshold mechanisms and site specificity in chromium(VI) carcinogenesis","volume":"21","year":"2000","journal-title":"Carcinogenesis"},{"key":"ref_13","doi-asserted-by":"crossref","first-page":"1027","DOI":"10.1080\/10643389.2018.1564526","article-title":"A critical review on bioremediation technologies for Cr(VI)-contaminated soils and wastewater","volume":"49","author":"Xia","year":"2019","journal-title":"Crit. Rev. Environ. Sci. Technol."},{"key":"ref_14","doi-asserted-by":"crossref","first-page":"17","DOI":"10.1289\/ehp.919217","article-title":"Chromium cycling in soils and water: Links, gaps, and methods","volume":"92","author":"Bartlett","year":"1991","journal-title":"Environ. Health Perspect."},{"key":"ref_15","doi-asserted-by":"crossref","first-page":"206","DOI":"10.1111\/j.0105-1873.2003.0230.x","article-title":"Chromium allergy: Significance of both Cr(III) and Cr(VI)","volume":"49","author":"Hansen","year":"2003","journal-title":"Contact Dermat."},{"key":"ref_16","doi-asserted-by":"crossref","first-page":"43","DOI":"10.1007\/BF02543005","article-title":"Oils, fats and waxes in the leather industry","volume":"17","author":"Newbury","year":"1940","journal-title":"Oil Soap"},{"key":"ref_17","first-page":"66","article-title":"Collagen D-Spacing and the effect of fat liquor addition","volume":"110","author":"Sizeland","year":"2015","journal-title":"J. Am. Leather Chem. Assoc."},{"key":"ref_18","doi-asserted-by":"crossref","first-page":"6637","DOI":"10.1007\/s12649-020-00944-3","article-title":"Synthesis of Fat Liquor Through Fish Waste Valorization, Characterization and Applications in Tannery Industry","volume":"11","author":"Saranya","year":"2020","journal-title":"Waste Biomass Valorization"},{"key":"ref_19","doi-asserted-by":"crossref","first-page":"221","DOI":"10.1590\/S0104-66322011000200006","article-title":"The influence of Chromium supplied by tanning and wet finishing processes on the formation of cr(vi) in leather","volume":"28","author":"Fuck","year":"2011","journal-title":"Braz. J. Chem. Eng."},{"key":"ref_20","doi-asserted-by":"crossref","first-page":"514","DOI":"10.1016\/j.jhazmat.2008.03.070","article-title":"Leather waste\u2014Potential threat to human health, and a new technology of its treatment","volume":"160","author":"Kolomaznik","year":"2008","journal-title":"J. Hazard. Mater."},{"key":"ref_21","doi-asserted-by":"crossref","first-page":"20","DOI":"10.1186\/s42825-020-00027-y","article-title":"Chromium and leather: A review on the ch, emistry of relevance for allergic contact dermatitis to chromium","volume":"2","author":"Hedberg","year":"2020","journal-title":"J. Leather Sci. Eng."},{"key":"ref_22","doi-asserted-by":"crossref","first-page":"244","DOI":"10.3390\/suschem5030016","article-title":"Use of Antioxidants to Reduce Chromium (VI) Formation during the Leather Tanning Process","volume":"5","author":"Salmi","year":"2024","journal-title":"Sustain. Chem."},{"key":"ref_23","doi-asserted-by":"crossref","first-page":"5265","DOI":"10.1023\/A:1012414416510","article-title":"Fatliquoring agent and drying temperature effects on leather properties","volume":"36","author":"Bajza","year":"2001","journal-title":"J. Mater. Sci."},{"key":"ref_24","doi-asserted-by":"crossref","first-page":"82","DOI":"10.1111\/cod.12581","article-title":"Chromium (III) and chromium (VI) release from leather during 8 months of simulated use","volume":"75","author":"Hedberg","year":"2016","journal-title":"Contact Dermat."},{"key":"ref_25","doi-asserted-by":"crossref","first-page":"1153","DOI":"10.1080\/10807039.2017.1308813","article-title":"Assessment of risk to human health due to intake of chromium in the groundwater of the Aosta Valley region, Italy","volume":"23","author":"Tiwari","year":"2017","journal-title":"Hum. Ecol. Risk Assess. Int. J."},{"key":"ref_26","unstructured":"(2017). Leather\u2014Chemical Determination of Chromium (VI) Content in Leather Part 1: Colorimetric Method (n.d.) (Standard No. ISO 17075-1:2017 IULTCS\/IUC 18-1). Available online: https:\/\/www.iso.org\/standard\/67096.html."},{"key":"ref_27","doi-asserted-by":"crossref","unstructured":"Bi\u0161kauskait\u0117, R., Valeikien\u0117, V., and Valeika, V. (2021). Enzymes for leather processing: Effect on pickling and chroming. Materials, 14.","DOI":"10.3390\/ma14061480"},{"key":"ref_28","first-page":"189","article-title":"A new chromium-zinc tanning agent: A viable option for less chrome technology","volume":"97","author":"Madhan","year":"2002","journal-title":"J. Am. Leather Chem. Assoc."},{"key":"ref_29","first-page":"7","article-title":"Effect of pickling materials on leather quality from a hide surface charge perspective","volume":"117","author":"Yang","year":"2022","journal-title":"J. Am. Leather Chem. Assoc."},{"key":"ref_30","doi-asserted-by":"crossref","first-page":"281","DOI":"10.1111\/cod.12406","article-title":"Chromium (VI) release from leather and metals can be detected with a diphenylcarbazide spot test","volume":"73","author":"Bregnbak","year":"2015","journal-title":"Contact Dermat."},{"key":"ref_31","doi-asserted-by":"crossref","unstructured":"Dou, X., Wang, Q., Zhu, T., Ding, Z., and Xie, J. (2022). Construction of effective nanosensor by combining semiconducting polymer dots with diphenylcarbazide for specific recognition of trace Cr (VI) ion in water and vitro. Nanomaterials, 12.","DOI":"10.3390\/nano12152663"},{"key":"ref_32","doi-asserted-by":"crossref","first-page":"1133","DOI":"10.1007\/s10098-020-01855-6","article-title":"Fast high-pressure tanning of animal skins by accelerated chromium sulphate complexation","volume":"22","author":"Prokein","year":"2020","journal-title":"Clean Technol. Environ. Policy"},{"key":"ref_33","doi-asserted-by":"crossref","first-page":"124699","DOI":"10.1016\/j.jhazmat.2020.124699","article-title":"Oxidation of trivalent chromium induced by unsaturated oils: A pathway for hexavalent chromium formation in soil","volume":"405","author":"Xu","year":"2021","journal-title":"J. Hazard. Mater."},{"key":"ref_34","first-page":"85","article-title":"Critical Appraisal of Analytical Procedures for the Determination of CR (VI) in Dyed Leathrs by 1, 5 Diphenylcarbazide Spectrophotometry after Sample Dilutin or Color Removal","volume":"102","author":"Scancar","year":"2007","journal-title":"J. Am. Leather Chem. Assoc."},{"key":"ref_35","doi-asserted-by":"crossref","first-page":"103503","DOI":"10.1016\/j.jconhyd.2019.103503","article-title":"Assessment of groundwater geochemistry and diffusion of hexavalent chromium contamination in an industrial town of Italy","volume":"225","author":"Tiwari","year":"2019","journal-title":"J. Contam. Hydrol."},{"key":"ref_36","doi-asserted-by":"crossref","first-page":"e051","DOI":"10.3989\/gya.0225141","article-title":"Relationship structure-antioxidant activity of hindered phenolic compounds","volume":"65","author":"Weng","year":"2014","journal-title":"Grasas Aceites"},{"key":"ref_37","doi-asserted-by":"crossref","first-page":"2513","DOI":"10.1134\/S1070363218120095","article-title":"Antioxidant activity of 2, 6-Di-tert-butylphenol derivatives in lipid peroxidation and hydrogen peroxide decomposition by human erythrocytes in vitro","volume":"88","author":"Kolyada","year":"2018","journal-title":"Russ. J. Gen. Chem."},{"key":"ref_38","doi-asserted-by":"crossref","unstructured":"Beya, M., Netzel, M., Sultanbawa, Y., Smyth, H., and Hoffman, L. (2021). Plant-Based Phenolic Molecules as Natural Preservatives in Comminuted Meats: A Review. Antioxidants, 10.","DOI":"10.3390\/antiox10020263"},{"key":"ref_39","doi-asserted-by":"crossref","unstructured":"Kmiecik, D., Fedko, M., Siger, A., and Kulczy\u0144ski, B. (2019). Degradation of tocopherol molecules and its impact on the polymerization of triacylglycerols during heat treatment of oil. Molecules, 24.","DOI":"10.3390\/molecules24244555"},{"key":"ref_40","doi-asserted-by":"crossref","first-page":"967","DOI":"10.1016\/S0891-5849(96)00433-9","article-title":"Electron paramagnetic resonance studies on nitroxide radical 2, 2, 5, 5-tetramethyl-4-piperidin-1-oxyl (TEMPO) redox reactions in human skin","volume":"22","author":"Fuchs","year":"1997","journal-title":"Free Radic. Biol. Med."},{"key":"ref_41","doi-asserted-by":"crossref","first-page":"1948","DOI":"10.1002\/cphc.201600114","article-title":"Employing Theories Far beyond Their Limits\u2014The Case of the (Boguer-) Beer\u2013Lambert Law","volume":"17","author":"Mutschke","year":"2016","journal-title":"ChemPhysChem"},{"key":"ref_42","doi-asserted-by":"crossref","first-page":"1","DOI":"10.3390\/analytica3010001","article-title":"The Evaluation of the Detection of Cr (VI) in Leather","volume":"3","author":"Davis","year":"2021","journal-title":"Analytica"},{"key":"ref_43","doi-asserted-by":"crossref","first-page":"13","DOI":"10.5755\/j01.erem.75.1.21050","article-title":"In silico, in vitro, in vivo Evaluation of Antioxidant Activity and Toxic Effects of Phosphorus-Containing Derivatives of 2, 6-Di-tert-Butylphenol","volume":"75","author":"Polovinkina","year":"2019","journal-title":"Environ. Res. Eng. Manag."},{"key":"ref_44","first-page":"250","article-title":"Controlling Cr (VI) in leather: A review from passive prevention to stabilization of chromium complexes","volume":"112","author":"Jing","year":"2017","journal-title":"J. Am. Leather Chem. Assoc."},{"key":"ref_45","doi-asserted-by":"crossref","first-page":"18","DOI":"10.1186\/s42825-023-00125-7","article-title":"Separation, speciation and quantification of both chromium (VI) and chromium (III) in tanned leather samples: A comparative study and validation of analytical methods","volume":"5","author":"Vievard","year":"2023","journal-title":"Collagen Leather"},{"key":"ref_46","doi-asserted-by":"crossref","first-page":"251","DOI":"10.1007\/s00217-004-1045-8","article-title":"Total and individual tocopherol contents of sunflower oil at different steps of refining","volume":"220","author":"Tasan","year":"2005","journal-title":"Eur. Food Res. Technol."},{"key":"ref_47","doi-asserted-by":"crossref","first-page":"642","DOI":"10.1111\/1541-4337.12867","article-title":"Tocopherols as antioxidants in lipid-based systems: The combination of chemical and physicochemical interactions determines their efficiency","volume":"21","author":"Barouh","year":"2022","journal-title":"Compr. Rev. Food Sci. Food Saf."},{"key":"ref_48","doi-asserted-by":"crossref","first-page":"671","DOI":"10.1007\/BF02522884","article-title":"The chemistry and antioxidant properties of tocopherols and tocotrienols","volume":"31","author":"Appelqvist","year":"1996","journal-title":"Lipids"},{"key":"ref_49","doi-asserted-by":"crossref","first-page":"1968","DOI":"10.1021\/je501049c","article-title":"Solubility of 2,5-Di-tert-butylhydroquinone and Process Design for Its Purification Using Crystallization","volume":"60","author":"Zhang","year":"2015","journal-title":"J. Chem. Eng. Data"},{"key":"ref_50","first-page":"105","article-title":"Antioxidant effect of tannic acid on formation of formaldehyde and hexavalent chromium compounds in leather","volume":"24","author":"Dandar","year":"2014","journal-title":"Text. Appar."}],"container-title":["Materials"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/1996-1944\/18\/8\/1858\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,10,9]],"date-time":"2025-10-09T17:17:09Z","timestamp":1760030229000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/1996-1944\/18\/8\/1858"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2025,4,18]]},"references-count":50,"journal-issue":{"issue":"8","published-online":{"date-parts":[[2025,4]]}},"alternative-id":["ma18081858"],"URL":"https:\/\/doi.org\/10.3390\/ma18081858","relation":{},"ISSN":["1996-1944"],"issn-type":[{"value":"1996-1944","type":"electronic"}],"subject":[],"published":{"date-parts":[[2025,4,18]]}}}