What is DMFa and where is it used?
DMFa stands for N,N-Dimethyl formamide and is a solvent or catalyst that can be intentionally used during the manufacturing of PU as it does not readily evaporate from solutions due to its high boiling point, and it is highly miscible with water. DMFa is also used in the manufacture of PU-based dispersions used for coating textiles to produce synthetic coated fabric.
DMFa is classified as toxic to reproduction (Reproductive toxic Cat 1B per EU 1272 / 2008 EC). Further, DMFa shows toxicity towards the liver in humans. On 22nd of November 2021, the Official Journal of the European Union published Commission Regulation (EU) 2021/2030 adding an entry 76 in Annex XVII of REACH Regulation (EC) No 1907/2006 for restriction on N,N-dimethylformamide (DMFa). Further, it is also listed as a cancer-causing chemical in the California Proposition 65.
All the solvents listed in the ZDHC MRSL V3.1 are banned for their intentional use and the commercial chemical formulations based on these listed solvents will always be non-conformant to ZDHC MRSL. Though banned and non-conformant, there are certain solvents or solvents-based chemistries (marked as 'EC' in the ZDHC MRSL V3.1) that suppliers may use under the time-bound phase-out strategy provided that adequate emission and exposure controls are in use. DMFa is listed in ZDHC MRSL V3.1, which means that the same applies to DMFa as well.
The permissible limit for unintentional contaminations in such formulations is 1000 mg/kg. This is not to be confused with any RSL limit for DMFa in the final product. Intentional use of DMFa is non-conformant with the ZDHC MRSL V3.1 (and future versions)!
As part of the usage ban, a brand should send a call to action to all their suppliers to phase out DMFa from their input chemical inventory or evaluate alternative production processes. DMFa is intentionally used as a solvent or catalyst when manufacturing PU and PU dispersions used for coating of textiles. Manufacturers are required to replace DMFa with suitable solvent-free technology or water-based chemicals. Industrial alternatives are available with many companies BASF, Covestro, Huntsman, Everlight Chemical Corporation, Nicca Chemicals, Hefei Ketian, Stahl, TFL etc.
DISCLAIMER Any mentions of innovations and/or innovative practices are provided as examples and shouldn’t be construed as the only ones available. Organisations are responsible to conduct their own research into all possible solutions to determine the best one for them.
For further information on the use of DMFa with proper emission and exposure controls, and how to investigate safer alternatives, check out the ZDHC Responsible Solvents Approach Guide V1.0.
The transition period for implementation of the ZDHC MRSL V3.1 ends on 1st November 2023. Thus, DMFa as a solvent or DMFa-containing formulations are not compliant with the MRSL V3.1.
ZDHC recognises that the change to solvent-free/water-based PU may take some time and thus ZDHC expects its brands to formulate a strategy and timeline to work toward the elimination of DMFa from their supply chain. Only once DMFa-based technologies and the use of DMFa are completely phased out, the supply chains can achieve ZDHC MRSL conformance.
Best practices for the use of DMFa with proper safety controls are covered in the ZDHC Responsible Solvent Approach Guide V1.0. Although this guidance document details best practices for the responsible use of solvents in general, Sections 1.2.3, 4.1, 4.2, and 6.1 are specifically and more directly related to the responsible use of DMFa.
After the end of the transition period for ZDHC MRSL V3.1 (i.e. 1st November 2023), all the chemicals listed in the ZDHC MRSL V3.1 (if used) will be considered as non-conformant.
Certain chemicals e.g. DMFa, trichloroethylene, ADCA etc., have been marked with EC (emission and exposure control). These ZDHC MRSL V3.1 non-conformant chemicals find application/use in certain processes where safer substitution/replacements have not been found or established, yet. In order to phase out such chemicals ZDHC urges the suppliers to carry out concerted efforts and show their development towards this phase out plan. Only if time-bound phase out goals are set and phase out actions are taken, this can be considered a “transition period” and emission and exposure control measures can be accepted for the time being.
During this transition period, the use of such EC-marked-chemicals needs to be carried out responsibly. ZDHC has suggested a ‘GUIDE’ document called Responsible Solvent Approach Guide V1.0, which will help suppliers during this transition phase. Nonetheless, the EC-marked solvents are ZDHC MRSL V3.1 non-conformant.