ZDHC stands for Zero Discharge of Hazardous Chemicals. The ZDHC Programme is an industry organisation of brands, chemical suppliers and manufacturers that develops guidelines and tools to reduce hazardous chemicals in textile, leather and footwear production. Many brands ask their suppliers to follow ZDHC guidelines.
This page summarises what ZDHC means in practice. The official ZDHC documents and platforms are the authority.
Main ZDHC tools#
MRSL (Manufacturing Restricted Substances List)#
The MRSL lists chemical substances that should not be intentionally used in chemical formulations used in facilities that process textile materials, trims, leather and footwear. It controls what goes into the process, as opposed to what remains in the finished product.
Chemical products can show their MRSL conformance through ZDHC's system, which has different conformance levels.
Wastewater guidelines#
The ZDHC Wastewater Guidelines set limits and testing requirements for wastewater and sludge from textile processing facilities (wet processing mills, dyehouses, laundries). Facilities test their wastewater and share results through the ZDHC platform.
Chemical management guidance#
ZDHC also publishes guidance on chemical management systems: chemical inventories, safety data sheets, storage, handling and training.
Gateway and reporting#
Suppliers and chemical companies use the ZDHC Gateway platform to check chemical product conformance and to share reports. Brands use it to see supplier performance.
MRSL and RSL#
| MRSL | RSL | |
|---|---|---|
| Controls | Chemicals used in manufacturing | Substances in the finished product |
| Applies to | Chemical formulations and facility inputs | Garments, fabrics, trims |
| Checked by | Chemical inventory, supplier conformance, wastewater testing | Product testing |
Both are needed. See restricted substances lists.
What a facility is typically asked to do#
- Keep a chemical inventory of all chemical products used, with safety data sheets.
- Check MRSL conformance of each chemical product, and replace non-conforming ones.
- Test wastewater (for wet processing facilities) according to the guidelines and share results.
- Store and handle chemicals safely, with labelling, secondary containment and training.
- Report through the platforms the brand requests.
Relevance for cut-and-sew factories#
A cut-and-sew factory uses fewer chemicals than a dyehouse, but it still uses spot-cleaning agents, machine oils, printing inks, adhesives and cleaning chemicals. Spot removers have historically been a concern in the industry. Keep an inventory, check products against the MRSL and the buyer's requirements, and control their use.
Common gaps#
- No complete chemical inventory.
- Chemicals bought from local traders without safety data sheets.
- Spot-cleaning chemicals used without approval.
- Wastewater testing done but not followed by corrective action.
Related: OEKO-TEX, buyer compliance audits.
Getting started as a supplier#
- Build a complete chemical inventory, including maintenance and cleaning chemicals.
- Collect current safety data sheets for every product.
- Check each product's MRSL conformance with the chemical supplier and in the ZDHC tools the brand uses.
- Replace or phase out products that do not conform.
- For wet processing sites, set up wastewater sampling and testing with an approved laboratory.
- Train chemical store staff and users, and review the inventory regularly.
Related guides#
- Global Recycled Standard (GRS): recycled standards that also include chemical requirements.
- Sustainable bio-scouring process: an example of cleaner wet processing.
- GOTS: organic certification with chemical input rules.
Frequently asked questions#
Is ZDHC a certification? ZDHC is a program of guidelines and tools, not a single product certification. Brands decide how they require suppliers to use it.
Does ZDHC apply to dry processes? The MRSL applies to chemical formulations used in facilities, including those used in cutting, sewing, printing and finishing. Wastewater guidelines apply mainly to wet processing.