Over the counter human medications, even those seemingly benign as aspirin, Tylenol or vitamins, can poison your bird. Commonly available bird products such as antibiotics, mite sprays or feather-picking "remedies" must also be avoided.
Don't expose your bird to household toxins, Certainly, don't expose your bird to second hand smoke, and make sure you wash your hands before handling your bird if you smoke, because nicotine residue on your hands can be dangerous to your bird.