Did a little more research and found pics from someone who disassembled their Solo 2 oven
after using the device for a while. I believe Air Max uses nearly the same oven design. It appears the air holes in the oven allow in heated air from the ceramic heating element, thermal putty, wires, etc. I didn't realize this was the case.
While the heating element and oven may be sealed from the large circuit board, it doesn't seem that the oven is isolated from the heating element - so the vapor inhaled includes hot air from the ceramic element, thermal putty, wires, etc.