While the article is quite accurate, this caught my eye:
Many Laser printers do something similar. I found this out the hard way when the "waste toner bag" exploded in one i was using and sprayed a toxic cloud of black dust around both the inside of the printer and the area surrounding it. The printer probably put about 1/4 of all its toner into the waste on each refill.
While laser printer toner cartridges do have a waste hopper, it is only there to catch the remnants of toner left on the drum after the image transfer process. It is not
there to catch cyclically purged (wasted) toner from a cleaning process. The cleaning cycle on a laser printer is strictly a manual (and frequently service mode only) procedure.
As an example... Most Drill-N-Fill operations never empty the cartridges waste hopper because that would require disassembly. Which is the very think they are trying to avoid by drilling a hole in the cartridge to refill it with toner. They do this based on the assumption (gamble) that they can get a few extra life cycles out of the cartridge before the seals (which have a 1 year shelf life...) fail. The get away with it simply because the waste hopper doesn't fill up that quickly because the bulk of the toner is actually getting used
. Unfortunately the (frequently expired) shelf life of the seals causes many of the DNF cartridges to fail. While DNF cartridge waste hopper overflows are also a problem, there not nearly as common an occurrence.
I work for an IT company that among other things re-manufactures toner cartridges (about 1,000 a month). We do a complete tear-down and reassembly of each cartridge, with new seals, and we have an extremely low failure rate. ...I do believe these two points are associated.