I sold a pair of Kimber SC's here years ago and the buyer had an allergic reaction after he got home with them.
Knowing that we have cat's he had taken an antihistamine prior stopping over to pick them up, but it wore off.
Apparently there was enough dander transfer to cause this.
I was once Beta testing a pair of power cables (also years ago) and by the time I received them in the mail chain they smelled so strongly of cigarette smoke I could not tolerate them in the home until the outer casing had been thoroughly cleaned with hydrogen peroxide 3% (which eliminated close to 100% of the oder).
I'm also deadly allergic to asparagus, but so far this has not been a HiFi problem.
No children allergies that I'm aware of.
DeKay