A toxic chemical that was sneakily added to OTC medications like Tylenol™
in the early '80's; its typical effect was to cause the meds’ consumers to
frequently heave deep fretful inhalations and
otherwise behave in a restless dissatisfied manner.
OTC meds are now “sealed for your
protection”, but that doesn’t seem to stop some grumpy
cantankerous individuals from exhibiting sighanide-like
symptoms, anyway.