dangerous.....
Petrol burns easily, so smoking is dangerous near it.
because It is
It is useful!
Yes, it is so flamable that it is dangerous !!!
Can cause cancer (leukemia), contamination of skin
Short answer Yes. Petrol is useful for running a engine, and extremely dangerous if misused.
You can't smoke in a petrol station because petrol especially has very volatile vapours. In theory petrol in the liquid where the air is controled will put out a flame which is beneth it. Petrol is at it's most dangerous in it's vapour and therefore smoking is a no no in petrol stations.
Petrol stations are potentially very dangerous, because petrol is fire hazard. If petrol leaks from pump for any reasons eg petrol nuzzle misused, or pipe crack or gets damages then petrol can leak onto forecourt and catch fire or even explode.
Petrol, it has a lower flash point and is more flammable than diesel
If you mean "dangerous" as in "more flammable" the carbon chains that make up petrol are shorter and that makes it easier to set alight than diesel. However, both substances contain benzene which is very toxic, incerasing the risk of cancer and other serious illnesses, so both can be considered "dangerous".
Diesel is less flammable than petrol. A build up of petrol fumes inside a boat is extremely dangerous, as a spark could ignite the fumes.