Tong Hong Tannery implements Sustainable Chemical Management to reduce environmental impacts

A successful ZDHC Supplier to Zero implementation

In 2012, Tong Hong, a split leather factory, started their ZDHC journey. The company managed to improve on their chemical management system, reduce harmful emissions, and boost worker health and safety.

Tong Hong sought a way to grow sustainable production, while reducing factory operating costs. Founder Micheal Shih comments: “It’s clear that my focus was not only on business growth, but also building sustainable targets in areas like production efficiency and environmental protection.”

In line with ZDHC’s holistic approach, Tong Hong looked at the inputs, processes and outputs associated with its activities. The benefits were felt by the entire business.

Input management

In 2015, Tong Hong incorporated the ZDHC MRSL into its Responsible Sourcing policy. Chemical suppliers were required to complete MRSLConformance Level 1 certification by March 2021. To increase the number of compliant suppliers, Level 3 certification was promoted to all chemical formulators in April 2022.

ZDHC InCheck reports

The ZDHC Gateway highlighted chemicals that could replace hazardous substances. Tong Hong also worked with formulators to create safer alternatives. By April 2022, ZDHC InCheck data showed the compliance ratio for chemicals used in the factories was over 70%, with 36% at Level 3.

Better process management

ZDHC Academy training

Courses such as the ZDHC Chemical Management System (CMS) Training helped to improve their chemical management system. In 2021, Tong Hong achieved Progressive Level within the Supplier to Zero Programme, being the first factory in the leather industry to do so.

Output management for reduced emissions

Wastewater system upgrade

Tong Hong meetsZDHC Wastewater Guideline standards and 60% of their treated wastewater is directly reused for production. It also met national tanning industry standards ahead of time. Michael Shih notes: “recycled water usage is our first priority, hence our partnership with ZDHC”.


ZDHC ClearStream reports

With Tong Hong having met their requirement for leather, they and their connected brands can check their wastewater performance via ClearStream reports on the ZDHC Gateway. This gives brands visibility over their connected factories’ wastewater discharge.


100% water-based chemicals eliminate gas emissions of VOCs

PU products often require solvents, creating air emissions that impact employee health and safety. Tong Hong worked with an Italian TFL company to develop water-based chemicals and invested $50 million on water-based PU products.

Closing the loop with solid waste recycling

To further mitigate their environmental impact, in 2021, Tong Hong’s Vietnam operation finished building an industrial gelatin factory, repurposing one their leather’s byproduct, and work began on a recycled leather factory in China.

Enhanced CMS and commercial benefits

Going through the questions on the ZDHC Supplier to Zero platform helped Tong Hong’s factories to improve their chemical management practices and remove harmful substances at source. This boosted health and safety, reduced the discharge of harmful substances, and contributed to their zero emission goals. Being on the ZDHC Gateway also makes it more visible to brands, who can connect Tong Hong’s zero-emission factory action plan to their own sustainability goals. As a result, Tong Hong's reputation grows, as will order volumes.


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About Supplier to Zero

ZDHC enables suppliers to take ownership of their continuous improvement efforts and chemical management performance. The ZDHC Supplier to Zero Programme helps companies realise their potential in this regard. Suppliers can target improvements in sustainable chemical management.Its online platform empowers suppliers to systematically implement ZDHC best practices, reducing cost and risk in chemical processes, while unleashing efficiency gains.

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