If you’re worried about things exploding or something, don’t worry. Unless you were exciting a fuel/air mixture up to the combustion point you have nothing to worry about. So that would take a deliberate change to the chemical makeup of the air and much much much higher transmit power levels.

But I guess you should be careful if you are trying to modify this into an RF pulse welder and someone left their cutting torch gas cylinders venting nearby. </s>