Comparison of Technologies: Ink versus Laser: Corona wire = Ozone
Laser technology requires a static electrical charging of the imaging drum. This can be accomplished by a transfer roller, which is in direct contact with the imaging drum. This charging process generates little or no ozone.
Brother´s printer uses a corona wire, which charges the imaging drum with high voltage. Toxic ozone accrues in the small gap between corona wire when the imaging drum is charged.
There is no ozone filter - the fan (picture below) blows the air unfiltered into the environment.