CHROMIUM VI UPDATE 2023

The tanning industry, especially in Europe, needs to fight a political battle if it is to remain viable

By H. Procter
The industry finds itself in a situation that it has never seen before. The science surrounding the future use of chromium salts seems to be irrelevant. At the moment, the science assessed by the European Chemical Association (ECHA) Risk Advisory Committee (RAC) does not seem to have any regard to the rights and livelihoods of the over 1 million people who are directly affected by a change that restricting chromium VI (Cr VI) will have.
The ECHA, using a respiratory sensitiser route, has removed the possibility of replacing chromium with glutaraldehyde - by adding glutaraldehyde onto its REACH Annex XIV - effectively banning it (a manufacturer has to obtain authorisation to use it). Obtaining authorisation is nigh impossible when a viable (and economic) alternative exists - ironically the viable alternative to GTA is chromium. How have the tables turned with glutaraldehyde having been previously listed as the alternative to chromium?

Science of Cr VI
The formation of Cr VI has been covered in a lot of detail, and its management is explained in the Leather Working Group and Sustainable Leather Foundation’s guidelines. The levels of chromium VI found in leather is limited to 3 mg/kg (3 ppm). Last year S&V African Leather featured the current regulatory detail:

“On 17 September 2021 the opinions of the ECHA RAC and SEAC (Socio-Economic Advisory Committee) were published that concluded on proposals to include Category 1/1A/1B carcinogens (including Cr VI) as part of restrictions to articles that would encounter human skin presented to the ECHA as an Annex XV dossier from Sweden and France. The proposed restriction for textiles and leather was to limit the levels of Cr (VI) to 1 mg/kg (1 ppm).

However, the SEAC had taken from the RAC that there were limitations on the accurate detection of Cr (VI) in chromium-tanned leather at 1 ppm. It was concluded that the detection of Cr (VI) in a cloud of Cr (III) was prone to errors. The conclusion has since been correlated by Davis et al. (2022) and an alternative detection method should be considered. Based on these reservations, the Annex XV for skin sensitisers, has been taken through for ratification, with the following exception. The exception is to include a temporary reprieve for leather (the restriction will be maintained at 3 mg/kg, 3 ppm) for 5 years (to end in 2026). Textiles will be limited to 1 ppm by the Annex XVII entry on skin sensitisers imminently.”

Timeline
The timeline given hasn’t galvanized any further. Many senior members of the European and Global tanning industry have a range of opinions which range from the review being as early as next year to the original 2026 date given above. The current understanding is that when the revision is done, and if the limit is lowered to 1 ppm, then the industry will have 5-6 years to meet those new requirements.
It is a priority for the industry to understand that and to start preparing a political case as to why this should not be done. The court case in the United States that is examining the Proposition 65 restrictions and management of Cr VI in articles is demonstrating that this is becoming political fast.

Politics
The SEAC and the court case in the US has come down to the political power that the leather industry has - which as a small industry is negligible. If the restrictions proposed were pharmaceutical interests, then billions of lobbying dollars would be used to influence and minimise the changes that the industry would be experiencing. An example of this was seen in the EU when isocyanates (part of the mighty polyurethane, PU, industry) were proposed for REACH regulation - the concern was human health. Instead of using REACH, the EU used the Chemical Labelling and Packaging (CLP) to make people safer - by having it labelled in a certain way and forcing Europeans to use the appropriate personal protective equipment.
The PU industry had the political power and financial backing to find a compromise with those looking to minimise risk. Let us be clear, the outcome was making people safer, the CLP route did that. Was it corruption? No, the money and influence were used to find a concession, a compromise that would make people safer, and to serve the community and financial interests of an industry.
The case of glutaraldehyde and chromium could, if played right if the industry can get organised. The industry needs clarity on the timeline of the proposed 1 ppm revision and then needs to put together a political strategy that makes a strong SEAC case and has buckets of science to back up that the current Cr VI restrictions are appropriate. It needs to identify a political compromise that keeps people safe from the perceived, while using the best safety and policy practice to keep the tanning industry competitive - a chrome-free future in the EU is going to make the EU less competitive than other parts of the world. It does also mean that anyone wanting to import leather into the EU will need to comply with the 1 ppm restriction (if that is successful).

Other questions
The European tanning industry currently has its back to the wall. It is struggling to see a future without bisphenols, and without glutaraldehyde. The latest additions to the Candidate List include melamine, such that the retannage of chromium-free leathers has lost most of its retanning toolbox - no phenols, formaldehyde, no diphenyl sulfones, no melamine, leaving vegetable tannins, proteins, lignins, as the main tools available. Acrylics and other petrochemicals are also available but get caught out by tanners wanting to keep things biogenic.
So, what if Cr VI moves to 1 ppm? Can tanners even make a full chromium tanned leather at that level? Work is currently underway to answer that question as is work to see if a new detection method (that can resolve down to parts per billion level). If the industry cannot make leather down to 1 ppm level, then chromium is effectively banned.
In the absence of chromium, how fast can the industry gear up to produce tanning agents at the level that - considering an international shortage of vegetable tanning agents and the range of chromium-free chemistry that has just been banned.

In the next issue: ASTM 6686. What is new carbon and why is the biogenic carbon so important to leather remaining competitive with plastics and new materials going forward. Can we tell the difference between new carbon and fossil carbon? Are vegan materials always plastic? Can leather be friends with biogenic vegan materials?