Can the A/C in car produce Benzene enough to cause cancer?
A WhatsApp forward I recently received talked about the Benzene fumes produced in the car that's standing still in direct sunlight. The message said that these Benzene fumes can cause cancer and therefore, whenever you are about to start your journey - it's better to let the windows open for some time; before turning on the air conditioner.
I checked online if there's any truth in the message; and found out that CANSA has an article dedicated to this: https://www.cansa.org.za/urban-legend-benzene-fumes-from-car-dashboard/
The article says that car cabins were studied and they were found to have about 149 ug/m(3) of benzene. However, the message said that the car cabin would contain about 400 - 800 mg benzene.
Did you notice the difference between 'ug' and 'mg'? The WhatsApp message indicated that the car cabins would contain about ~2000 - 4000 times that of the quantity that was found to be in the tests.
Therefore, it's safe to assume that turning on A/C in your car without letting the air pass won't really cause cancer. However, you could still let the windows open for some time to get rid of the odors accumulated in the car.
What's your take on this?
Usual scare mongering in my opinion.
A definitive study showed a maximum of about 90microgram/m3 in new cars and somewhat higher in cars with large mileage travelled. I do agree with @Kaustubh Katdare that it is a good practice to air the car to remove all stale air before starting out.