You are most certainly technically incorrect, which is the worst kind of incorrect. It would take very very high levels of ozone to be anywhere near as promptly fatal as carbon monoxide poisoning from running a gasoline powered car inside a closed garage. As far as I know, no one commits suicide by running an electric motor in a closed room. Ozone causes oxidative damage to tissues, including the delicate tissues of your lungs. Carbon monoxide shuts down the oxygen carrying function your hemoglobin. You can be killed by unnoticeable levels of carbon monoxide. It&#x27;s highly unlikely you won&#x27;t be able to sense dangerous levels of ozone. In fact, it&#x27;s likely to be unpleasant enough to drive you from the room. Whereas CO makes you feel sleepy as you slip down to unconsciousness forever.<p>(EDIT: That said, ozone in rather small amounts can be quite damaging to long term health.)