Epson EPL-6100 Reference Manual page 13

When removing the developer cartridge, never touch the
developing roller under the flap; otherwise, print quality will
decline.
When handling the developer cartridge, always place it on a
clean, smooth surface.
Do not turn the developer cartridge upside down or stand it
on its ends.
Do not attempt to modify or take the developer cartridge
apart. It cannot be refilled.
Do not touch the toner and avoid all contact with your eyes.
3