Son used spray paint in art class yesterday w/out a mask. is concerned about risk of long term health problems. any info you can provide to reassure?

Unlikely a problem: The VOC's (volatile organic compounds) released by a single can or so of spray paint in a well ventilated room is unlikely to produce any significant harm. Kids who "huf" or spray the contents in a bag and inhale the smell to get high are doing so at high VOC concentrations that are trapped in the process.These kids will kill brain cells.