Canon FAX-L120 Basic Manual page 21

Do not remove the cartridge from the machine unnecessarily.
Do not open the drum protective shutter on the cartridge. Print quality may
deteriorate if the drum surface is exposed to light or is damaged.
Always hold the cartridge by its handle to avoid touching the drum protective shutter.
Do not stand the toner cartridge on end, and do not turn it upside down. If toner
becomes caked in the cartridge, it may become impossible to free it even by shaking
the cartridge.
CAUTION
Do not place the toner cartridge in fire. Toner powder is flammable.
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