Environmentally Friendly Leather Tanning Using Enzymes

EPA Grant Number: SU835511
Title: Environmentally Friendly Leather Tanning Using Enzymes
Investigators: Cao, Huantian , Wu, Changqing , Scudder, Crescent , Siron, Leslie , Xu, Wenqing
Institution: University of Delaware
EPA Project Officer: Packard, Benjamin H
Phase: I
Project Period: August 15, 2013 through August 14, 2014
Project Amount: $14,999
RFA: P3 Awards: A National Student Design Competition for Sustainability Focusing on People, Prosperity and the Planet (2013) RFA Text |  Recipients Lists
Research Category: Pollution Prevention/Sustainable Development , P3 Challenge Area - Chemical Safety , P3 Awards , Sustainable and Healthy Communities


Current leather tanning methods use a high level of chemical agent inputs creating a lot of chemical output pollution. Of particular concern is the use of chromium (III) as the tanning agent, which if oxidized becomes chromium (VI), a known toxin and carcinogen. Compared with other tanning methods such as vegetable tanning, chrome tanned leather has very high hydrothermal stability, and is softer and more pliable. This is the reason that although chrome tanning causes a lot of water, solid waste, air and worker health problems, it still accounts for 90% of tanning production. The goal of this project is to investigate environmentally friendly leather tanning process using enzymes, and a combination of enzymes and non-toxic chemicals from plants. A successful combination of bio-based alternatives using enzymes and plant chemicals would be an innovative approach to leather tanning.


This is an interdisciplinary project with collaboration between students and faculty in the Department of Fashion and Apparel Studies (FASH) and Department of Animal and Food Sciences (ANFS) at the University of Delaware (UD), with Dr. Eleanor Brown of US Department of Agriculture Eastern Regional Research Center (USDA ERRC) serving as an external partner/mentor. The team will complete six tasks: (a) selecting and obtaining raw hides and conducting enzymatic pre-tanning processes to remove hairs and fat; (b) investigating tanning processes using enzymes; (c) investigating enzyme-assisted vegetable/chemical tanning processes using a combination of enzymes and non-toxic chemicals from plants; (d) evaluating the tanning effectiveness, textile properties of the leather and environmental impact of the tanning process; (e) designing and developing leather accessories; (f) developing educational tool.

Expected Results:

The effectiveness of the leather tanning will be evaluated by measuring shrinkage temperature, and analyzing leather structure using Scan Electron Microscope (SEM). The team will also measure leather physical/mechanical properties, including softness, tensile strength, elongation and modulus, and abrasion resistance, as well as environmental performance such as BOD, COD, TS (total solids), in accordance standard methods. The team expects to optimize an environmentally friendly leather tanning process that produces comparable physical traits to conventional chrome tanned leather.

Supplemental Keywords:

green chemistry, green manufacturing, environmentally benign substitute, biotechnology, toxic use reduction;

Progress and Final Reports:

  • Final Report