Carbon monoxide — Indiana Permit Test

You cannot see, smell or taste carbon monoxide, and symptoms include drowsiness, dizziness, headache and blue lips.

Because you cannot sense the gas, the symptoms are your only warning.

You cannot see, smell, or taste carbon monoxide.

Never let your vehicle's engine run in a closed garage.

Exhaust fills a closed space quickly and can kill in minutes.

Never let your vehicle’s engine run in a closed garage

In congested traffic, close the fresh-air vent; on highways in cold weather, open it.

In a jam, outside air is full of other cars' exhaust; on the highway it is clean.

In congested traffic, close the fresh-air vent

Carbon monoxide is most likely to leak in when the heater is running, the exhaust system is faulty, or you are in heavy traffic.

A faulty exhaust can leak poison into the back seat without anyone noticing.

Carbon monoxide is most likely to leak into a vehicle when its heater is running, when the exhaust system is not working properly, or in heavy traffic where exhaust fumes are breathed in from other vehicles.

How can you tell carbon monoxide is in your car?

By symptoms such as dizziness or headache. Because you cannot sense the gas, the symptoms are your only warning. Indiana Driver's Manual, p.62: “You cannot see, smell, or taste carbon monoxide.”