The ZDHC Wastewater Guidelines set a unified expectation for wastewater quality in the textile, apparel, leather, and footwear industry. Including; reporting limits for traditional (conventional) parameters and hazardous chemical parameters, sampling and reporting frequency. By doing so, the Wastewater Guidelines aim to reduce the workload and cost faced by suppliers in satisfying multiple brand-specific testing requirements.
The current version of the ZDHC Wastewater Guidelines V.2.2, can be found here.-
Foundational limits were met by 90%
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Progressive limits were met by 50%
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Aspirational limits were met by 20%
What is the reason for removing the footnote on Table 1E Dimethyl formamide; N,N-dimethylformamide (DMFa)?
The footnote ‘Sample and Report only for mock leather.’ has been deleted as this applies to all leather and mock leather facilities, not only mock leather. The reason for this is it was not possible for the testing laboratories to know if a facility was a mock leather or not a mock leather facility.
Within the ZDHC Wastewater Guidelines we do not identify synthetic materials eg PU, so these are classed into the same category as leather.
Why has dyes-navy blue colourant been updated to not applicable in the ZDHC Wastewater Guidelines? What does this mean for testing?
Dyes-navy blue colourant: Component 1: C39H23Cl-CrN7O12S 2Na and Component 2: C46H-30CrN10O20S2 3Na, are not required to be tested within ZDHC wastewater testing. These parameters are not in the scope of wastewater testing.
However, we have kept these parameters in the guidelines to prevent the intentional use of these in the chemical inventory and production process.
Why has silica been updated to not applicable in the ZDHC Wastewater Guidelines? What does this mean for testing?
Silica (CAS no: 14464-46-1) is not required to be tested within ZDHC wastewater testing. This parameter is not in the scope of wastewater testing.
However, we have kept this parameter in the guidelines to prevent intentional use in the chemical inventory and production process.
What substances that were previously not applicable in Table 1 for leather in V2.1 now have limit values applied in V2.2?
Previously, there were no limit values applicable for leather for:
- Flame retardants
- Other/miscellaneous chemicals
- UV absorbers
- Tuolene
- Xylene
From November 2024 these are required to be tested within the ZDHC wastewater testing. The reason for including these into the scope of testing is to align the ZDHC MRSL V 3.1, in which these parameters require testing on leather.
This will be with effect with the implementation of WW 2.2 and earlier parameters.
What parameters that were previously sample & report in Table 3 for leather in V2.1 now have limit values applied in V2.2?
Previously, there were no limit values applicable for leather for:
- Dissolved Oxygen (DO)
- Total Dissolved Solids (TDS)
- Total chlorine
The Wastewater Council has analysed the data collected across the reporting cycles and found that a large proportion of facilities could achieve the required limit. Therefore, it has been decided to apply a single limit for these parameters rather than just Sample & report.
Why was the footnote for antimony deleted, and what does this mean for testing?
Previously, there was a footnote for antimony stating to Sample and Report for polyester facilities. However, it was observed that testing laboratories were unable to confirm whether a facility was a polyester facility or not.
The Wastewater Council has analysed the data collected across all textile facilities and found that a large proportion of facilities could achieve the required limit. Therefore, it has been decided to remove the footnote and apply the limit to all textile facilities, including polyester facilities.
No. It does not depend on the size of the facility. It depends only on the discharge type and daily discharge volume of industrial wastewater as below.
What happens when a boron flame retardant non-compliance is found in the wastewater?
As per the ZDHC Wastewater Guidelines V2.2 (ZDHC WWG V2.2), five boron based flame retardants (boric acid, diboron trioxide, disodium octaborate, disodium tetraborate anhydrous, and tetraboron disodium heptaoxide, hydrate) are detected as total elemental boron via ICP (Inductively Coupled Plasma) spectroscopy method. Therefore, if the total elemental boron content is higher than 500 μg/L, then all five boron flame retardants will be marked as non-conformant in the ClearStream Report.
There could be instances where manufacturing facilities that do not use flame retardants detect elemental boron concentrations in their wastewater beyond the threshold limit of the ZDHC WWG V2.2. In these scenarios, a facility should conduct a proper root cause analysis to find the reason for the boron detection. A thorough examination of all input chemicals (including commodity, sundry, and lab chemicals) and inlet water should be completed. The manufacturing processes should also be studied, including the raw materials used (which may contain contaminants).
Elemental boron is not a restricted substance itself in the ZDHC MRSL V3.1 or ZDHC WWG V2.2. But it is advised to know the root cause if the total elemental boron is detected above the limit of 500 μg/L