Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
. 2025 Mar;92(3):234-240.
doi: 10.1111/cod.14729. Epub 2024 Dec 3.

A Method to Distinguish Chromium-Tanned Leathers With Low and High Risks of Surface Hexavalent Chromium

Ivan Chen  1 , Jonas F Hedberg  2 , Yolanda S Hedberg  1   2
Affiliations

A Method to Distinguish Chromium-Tanned Leathers With Low and High Risks of Surface Hexavalent Chromium

Ivan Chen et al. Contact Dermatitis. 2025 Mar.

Abstract

Introduction: Traces of hexavalent chromium, Cr(VI), are a major concern for skin contact with Cr-tanned leather. Current extraction methods (ISO 17075-1:2017) for Cr(VI) testing do not necessarily reflect the true potential of surface-formed Cr(VI), as extracted concentrations are dependent on previous storage and atmospheric conditions.

Objectives: To test whether a spiking method protocol can distinguish leathers with high and low risks of releasing Cr(VI).

Methods: Two groups of leather types were selected based on previously detected Cr(VI) (group A) and optimal tanning practices with high antioxidants (group B), corresponding to a high and low risk of forming and keeping Cr(VI). Leathers were spiked with different concentrations up to 10 mg/kg of Cr(VI) and incubated at 80°C for 24 h prior to the ISO 17075-1:2017 extraction protocol.

Results: All Cr(VI) was reduced by group B leathers, whereas all group A leather extracts contained detectable Cr(VI) that was dependent on the exact leather type and the amount initially spiked.

Conclusion: Pre-treatment of samples with supplemental Cr(VI) is a potential method for determining the reduction capabilities of leather, which are closely related to the risk of Cr(VI) formation. 10 mg/kg spiking unambiguously distinguished leathers with high and low risks of forming Cr(VI).

Keywords: allergic chromium dermatitis; hexavalent chromium; humidity; leather; reduction; speciation; vegetable tannins.

PubMed Disclaimer

Conflict of interest statement

The authors declare no conflicts of interest.

Figures

FIGURE 1
FIGURE 1
Schematic illustration of the experimental protocol. Adapted from the ISO 17075‐1:2017 method for colorimetric determination of chromium in leathers. Modifications are visually represented (spiking and heating). Curve fitting is visually depicted through two examples of UV–vis spectra (to the right) produced by A3 (top) and B1 (bottom) leather samples for non‐spiked (0 mg/kg), 3 mg/kg, and 10 mg/kg Cr(VI) pre‐treatments.
FIGURE 2
FIGURE 2
(a) Extracted Cr(VI) from non‐spiked (0 mg/kg), 3 mg/kg spiked, and 10 mg/kg spiked samples across 10 leather types. < LOD represents Cr(VI) concentrations below the limit of detection. The error bars represent the standard deviation of independent triplicate samples. Statistically significant differences between spiking concentrations (p < 0.05) are denoted with an asterisk (*). The two dashed lines correspond to 3 and 10 mg/kg extracted Cr(VI). (b) Extracted Cr(VI) as a function of added Cr(VI) together with curves (red dashed lines) representing theoretical samples without any reduction capacity for Cr(VI). Corresponding raw data and values in μg/cm2 are given in Table S1.
See this image and copyright information in PMC

Similar articles

See all similar articles

References

    1. China C. R., Maguta M. M., Nyandoro S. S., Hilonga A., Kanth S. V., and Njau K. N., “Alternative Tanning Technologies and Their Suitability in Curbing Environmental Pollution From the Leather Industry: A Comprehensive Review,” Chemosphere 254 (2020): 126804, 10.1016/j.chemosphere.2020.126804. - DOI - PubMed
    1. Hedberg Y. S., “Chromium and Leather: A Review on the Chemistry of Relevance for Allergic Contact Dermatitis to Chromium,” Journal of Leather Science and Engineering 2, no. 1 (2020): 20, 10.1186/s42825-020-00027-y. - DOI
    1. DesMarias T. L. and Costa M., “Mechanisms of Chromium‐Induced Toxicity,” Current Opinion in Toxicology 14 (2019): 1–7, 10.1016/j.cotox.2019.05.003. - DOI - PMC - PubMed
    1. Adam C., Wohlfarth J., Haußmann M., et al., “Allergy‐Inducing Chromium Compounds Trigger Potent Innate Immune Stimulation via ROS‐Dependent Inflammasome Activation,” Journal of Investigative Dermatology 137, no. 2 (2017): 367–376, 10.1016/j.jid.2016.10.003. - DOI - PubMed
    1. Buters J. and Biedermann T., “Chromium(VI) Contact Dermatitis: Getting Closer to Understanding the Underlying Mechanisms of Toxicity and Sensitization!,” Journal of Investigative Dermatology 137, no. 2 (2017): 274–277, 10.1016/j.jid.2016.11.015. - DOI - PubMed