Lexus 2004 LS430 Owner's Manual page 276

AIR CONDITIONING
When the ignition switch is turned on, the xenon tube comes
on even if the rear air conditioning or rear fan is not operating.
This does not indicate a malfunction but is required for the long
use of the photocatalyst.
NOTICE
D Do not look into the xenon tube in the air purifier
through the filter slot and do not expose your skin
directly to the light in the xenon tube also. Although
the xenon tube scarcely issues less than 300nm
ultraviolet rays which are thought harmful for the
human body, some people may have symptoms such
as eye sore, vision trouble, skin inflammation, etc.
D Do not disassemble the air purifier, or it may cause a
malfunction. As some part in the purifier is under
high voltage, you may get an electric shock when you
touch it.
D The filters should be installed properly in position.
The use of rear air conditioning controls with the filter
removed may cause the malfunction of the rear air
conditioning controls.
D Turn on the air conditioning with a filter in position.
The activation without an filter may not only cause a
malfunction of the system but also dirty the interior
by spouting dust.
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