Toner for a electrostatic copier/printer is basically just coloured plastic powder and depending on the model sometimes a bit of magnite.
It is easy to clean up just use a vacuum cleaner that can cope with very fine particles. If unsure call out the company who service it and ask very nicely if they could send an engineer with a VAC as they will all carry a specialist VAC for toner.
Don’t use a crappy VAC as it will just suck in the toner and then blow it straight back out again and in the worse case explode.