There have been recent reports (Paris 2024 offers new Olympic medal after Huston says bronze looks ‘like it went to war’) that more than 100 winners from the 2024 Summer Olympic Games have seen rust and flaking on their winner’s medals. They have been returning them to the mint that made them for replacing. The damage appears to have caused by a recent switch by the manufacturer to an anti-corrosion treatment to comply with new EU regulations that ban the use of chromium trioxide. I gather that the third place bronze medals were most affected.
Chromium trioxide is a key component in chromic acid anodising, which creates a hard protective insulating metal oxide layer on the surface of components, providing wear and corrosion resistance. It has been used extensively. But chromium trioxide is toxic and poses health risks. It is classified as a carcinogen and can cause serious harm through various routes of exposure. Last year, under REACH, its use was severely limited in Europe. By the way, my guess is that the post-processing, anodised medals presented negligible risk to the athletes. But they don’t look great.
Manufacturers and suppliers of chemicals are increasingly challenged by regulatory advances like this. I don’t think it’s a bad thing, of course – quite the opposite. Just like we don’t send small children up chimneys any more, we don’t expose workers to asbestos, we have removed lead from paint and batteries, and we don’t use mercury in thermometers. There are countless more examples where regulations like REACH and RoHS are improving occupational health and safety every day. As we have greater understanding of the hazards (especially over longer time frames) and our attitude towards risk in the workplace develops (remember the chimney sweeps…), more legislation and regulation is introduced. Hazards to other living things besides people, and the environment, are factored in too.
The challenge for suppliers isn’t in removing the compounds and constituents which are deemed hazardous. The challenge is finding replacements which are just as effective in their task. As the French medal-making mint has found, this is not easy, and can go wrong.
Our suppliers are typically really good about this. The key is timely communication. “We have to replace constituent X with constituent Y, because of this regulation. Because of that, we are going to give the reformulated product a new reference. We will publish revised information and safety data sheets. We encourage you to fully evaluate the new formulation to make sure it still performs to your requirement, and we will give you samples to facilitate that. We are going to give you as much notice as we reasonably can about the change.”
Sometimes, we can’t find an answer; we can’t replace one component with another and produce a drop-in replacement, or even something similar. We may have to persevere with the existing product. We have this issue with mercury and isocyanates, for example.
Despite the use of mercury being much reduced, mercury based UV curing lamps are still available. LED based UV curing lamps are the default position these days, but in some applications, they do not cure adequately. Fortunately, the amount of mercury in these lamps is very small, and contained within the lamp. Do note the regulations for safe end-of-life disposal.
Isocyanates are hazardous chemicals, but are a fundamental constituent of polyurethane (PU) adhesives. Despite efforts to find a substitute, no isocyanate = no PU. There are now regulations about mandatory training of operators on the use of PUs. We have some PU adhesives which have micro-emission technology, so very low diisocyanate content – the isocyanate risk is greatly reduced and no training is required. And, virtually no isocyanates can be found in cured materials.
Flaky Olympic medals are not life threatening. Working in a manufacturing environment shouldn’t be either. A combination of regulation, product choice, risk assessment, process and training must ensure that it isn’t.
