What exactly does this mean? I've been noticing this a lot in mainly the mineral cosmetics. There are certain ingredients I know I need to avoid such as "bismuth oxychloride", but what does it mean when the label says: "may contain, bismuth oxychloride"? There are a few promosing products I would have liked to try but steered away from because of this warning.  How conerned should I be if it "may contain" the ingredients I'm sensitive to...or should I just go for it!

Thanks for any ideas! 
Amy
OSNT