Apple LaserWriter 12/640 PS - Manual (Page 379)

Ozone emission
Ozone gas is emitted by almost all laser printers and photocopiers. The
LaserWriter 12/640 PS printer technology allows it to emit practically no
ozone gas (less than .01 parts of ozone per million parts of air). The current
OSHA permissible exposure limit for ozone is 0.1 parts of ozone per million
parts of air (ppm). The ozone emissions from the LaserWriter 12/640 PS
printer comply with Underwriters Laboratory (UL) safety limits.
Depending on the levels of concentration, ozone can be a mild-to-severe
irritant with known effects ranging from dry throat and nose, headache, and
sore eyes to nausea, vomiting, and pulmonary congestion. For this reason
various regulatory agencies have established limits regarding the amount of
ozone to which employees may be exposed. The employer is responsible for
providing a work environment that meets these standards.
You can usually identify ozone by its characteristic odor, even in
concentrations well below the permissible exposure limit. However, as the
concentration of ozone or the duration of exposure increases, your ability to
smell it may decrease.
To minimize ozone exposure, install the LaserWriter 12/640 PS in a well-
ventilated area and keep the equipment properly maintained. If there are
other laser printers or photocopying machines in the same area, additional air
circulation may be required. Do not place the LaserWriter 12/640 PS in a
small, enclosed space that lacks adequate ventilation. Position the printer so
that the fan exhaust does not blow directly into an individual’s face. Finally,
maintain the relative humidity between 30 and 70 percent. Extremely low
humidity can slow the natural breakdown of ozone in the air.
354 Appendix D