The ECHA (European Chemicals Agency) are currently looking into the substances used in inks used in tattooing and permanent makeup.
This has been ongoing for a few years now but it seems they are close to reaching some sort of guidelines for what chemicals (and in what quantities) can be used in these inks. It would seem the future holds a new set of regulations that could potentially shake up tattoo ink manufacturers and the substances they use to create their inks. This will no doubt have an affect on the industry as a whole.
Have a read of what the ECHA have been up to.