I believe the OTC codeine cough syrup (Robitussin AC, I think?) comes in the strength of 10mgs/5mls (one teaspoon). So you are only talking 240mgs total of codeine in a 120ml bottle. About the equivalent of 8 tylenol 3's per bottle.
It's been a long time since I've purchased this, and I believe I got it in Washington state some years ago.