Sulfites occur naturally in wine. They are also added to wine. In the US, wine bottled after mid-1987 must have a label stating that they contain sulfites if they contain more than 10 parts per million. In the EU an equivalent regulation came into force in November 2005.[2] Organic wines are not necessarily sulfite-free but they have no added sulfites. Wines made with organic grapes, however, may contain up to 100 parts per million, compared to conventional wines which may contain up to 350 ppm.