When in doubt, ventilate

Despite this finding, some drivers may still be concerned about the presence of any benzene vapors inside their car, especially given the World Health Organization's stated position that there is "no safe level of exposure" to the carcinogen. They may also worry, per the email warning above, that turning on the vehicle's air conditioner might exacerbate their exposure to trapped toxins by recirculating contaminated air. If that's the case, there's no harm done — and much peace of mind to be gained — by simply opening the windows and ventilating the car before turning it on.