According to Health Day News, you need to avoid open flames after using sunscreen spray becaues of a potential burn risk. "Certain sunscreen sprays worn close to an open flame may pose a risk of catching fire, the U.S. Food and Drug Administration warns.
The agency said it knows of five incidents in which people wearing sunscreen spray near sources of flame suffered significant burns that required medical treatment. The products involved in these incidents were recalled and should no longer be on store shelves.
However, many other sunscreen spray products contain flammable ingredients, commonly alcohol. The same is true for some other spray products -- including insect repellants and hairsprays -- and even some non-spray sunscreens, the FDA said." read more 
Do you use sunscreen sprays?