Yes gasoline is dangerous and should never be used in an enclose area. But lest we be too paranoid. Every few weeks many of us pour it into our lawnmowers, some with less spillage than others. In the days of non sealed gas tanks with carburetors, that occasionally would leak a little onto the intake manifolds, especially if flooded, and park those same cars in our garages. Some of them not far from gas water heaters.
Not that any of that is recommended or should be pointed to as a validation, I use a bit of gasoline for cleaning ball bearings before assembling a hub. In a cup, outside on my driveway not far from where I put gas in my mower. When I was younger I used a lot more, especially working on old cars and cleaning greasy bike parts. But now that I am older and only a shadow of my former self I am much more cautious.
John