i'm scared to death of anything mango because i am deathly allergic to mango fruit, had one experience in which 911 had to be called, fire trucks and ems came, i really thought i might die, etc. etc. . i've used mango butter in lotion bars with no problems, have handled it as little as possible, but am scared to death of it nonetheless.
yes, definitely some fragrance oils contain some essential oils, and if anyone's in any doubt, avoid it like the plague.
although fragrance oils are, for the most part, synthetic, don't bet on that 100 percent. you can't know what someone's going to be allergic to. and sometimes the consumer won't know themselves, it may be their first exposure.
this is one of the many reasons why you MUST HAVE LIABILITY INSURANCE!!!!!