See also:

Lubrication oil circulation in the refrigerant circuit
Operate the air conditioner compressor at a low engine speed (at idle or low driving speeds) a few minutes each month during the off-season to circulate its oil. ...

Engine exhaust gas (carbon monoxide)
WARNING ● Never inhale engine exhaust gas. Engine exhaust gas contains carbon monoxide, a colorless and odorless gas which is dangerous, or even lethal, if inhaled. ● Always properly m ...

California proposition 65 warning
WARNING Engine exhaust, some of its constituents, and certain vehicle components contain or emit chemicals known to the State of California to cause cancer and birth defects or other reproductive ...