I wouldn’t recomend it actually when styrene burns it releases:
Benzene Gas
Benzene, a highly carcinogenic substance, is the prime ingredient in styrofoam. Benzene gas is released by burning styrofoam.
Styrene Gas
Burning polystyrene foam releases toxic styrene gas, which is readily absorbed through the skin, respiratory system and gastrointestinal tract and can cause deep unconsciousness and death. Also, the vapor can damage the eyes and mucous membranes.
I personally am not touching the stuff