What are the health risks of chrome plating?
For decades, the galvanic process has been used to chrome parts. This chrome is only for aesthetic purposes and seeks to underline a line in the design, surround the side windows, or create, as in the 50s/60s, huge flashy grilles. The galvanizing process uses, as its name suggests, low voltage currents and various baths.
While improvements have been made since the 1850s/1860s (invention of the process), the fact remains that it uses chromic and sulfuric acid baths. There is therefore in chrome plating workshops, hexavalent chromium in the air breathed. This considerably increases the risk of cancer, in particular lung cancer, for operators. Thus, Europe has decided to (try to) ban hexavalent chromium (or chromium 6) from 2024
What alternatives for car manufacturers?
With this ban in Europe, several questions arise. Indeed, manufacturers must find credible alternatives to chromium plating by galvanization. There are different avenues, but for the moment the processes must be put into full-scale production. In addition, the additional cost is likely to be significant according to them.
We could therefore see chrome disappear from cars for several years, the time for a lasting solution. Problem: how are we going to do for the optics? Not everyone uses LEDs yet and therefore needs chrome reflectors. A temporary solution could be to replace the chrome elements by aluminum, or another metal which, although less shiny, could do the trick.
Nickel plating (use of nickel) could also do the trick. The electrolytic deposition of nickel by electroplating uses salts and not acids. Except that nickel is worth much more than chromium. We are at just over €18,000 per tonne of nickel compared to just over €8,000 for chrome. In short, these processes should increase the price of shiny pieces. And for some manufacturers like Rolls Royce or Bentley, the number and surface of chrome parts is important.
And for old cars?
For recent automobiles, manufacturers should turn to alternatives, or have these parts made outside Europe. After all, California won’t ban the practice until 2039, and other countries will continue to allow it.
But for the old automobile, this may pose a problem. The chrome parts of the “grannies” were it with the galvanic process. Redoing the chrome should therefore quickly require a lot of work to switch to nickel or go through another process. The craftsmen who do this do not have the means of change at all and should therefore remain with the galvanic processes, of nickel no doubt.
For the others, among the possible processes, there are vacuum deposition processes, as for plastic projectors. This involves, for example, a deposit of chromium vapor (under total NDLA protection), or magnetic cathodic projection which consists of ionizing an argon atmosphere (inert gas) which will strike a block of chromium, projecting into the enclosure atoms which will then be deposited on the surface to be chromed. It is an expensive and very very slow process.
Another possibility is thermal spraying (or metallization). There, the principle is to have a carrier gas expelled from a nozzle (or torch) which will transport chromium particles. This transport is done at high velocity and temperature so that the metal adheres to the part. But, this is only valid for parts that can withstand high temperatures and therefore not for ornamental parts of our cars.
Alt Ctrl Trans
The automobile is not the only consumer of chrome and there should be a lobby in Europe to push back the ban. In industry, we can note the initiative “Alt Ctrl Trans” (for ALTernative to Chrome Tri and hexavaLent for the TRANSport and TRANsformation sector) in pun with “Ctrl Alt Del” of IT. This consists, since 2019, of finding industrial alternatives to “hard chrome”. Indeed, in addition to a purely aesthetic shiny appearance, chrome is used to make surfaces harder and more resistant to friction.
Here again, nickel could have a role to play with nickel-boron baths. This is the solution that manages to combine most of the properties of chrome plating, without however achieving them all. Nickel phosphorus and nickel tungsten could complete the desired properties. A complexity of implementation which will, there too, increase the cost of the processes.
Note :chromium 6 has been theoretically banned since 2017 in Europe, but authorizations have been extended.