What does SML - Specific Migration Limit mean?

The SML (Specific Migration Limit) defines the maximum permitted migration of an individual substance from a packaging material into food.

While the OML (Overall Migration Limit) assesses the total migration of all substances, the SML focuses on specific substances or components – such as plasticisers, antioxidants, stabilisers or metal ions. SML values are defined in EU Regulation No. 10/2011, Annex I, which lists all substances authorised for food contact.

They are expressed in mg per kg of food (mg/kg food) and ensure that, even under long-term or high-temperature conditions, no harmful quantities migrate into the food.

Compliance with SML limits is verified in laboratories through migration simulations or specific chemical analyses of the test simulant. Depending on the intended use, the relevant OM test conditions (OM1–OM7) are applied.

Together, OML and SML form the basis of food-contact safety assessment for plastics. While OML covers the overall safety of the material, SML ensures control over individual substance migration. In short: SML evaluates the specific migration of single substances, whereas OML measures the overall migration of all components – both are essential for safe food packaging.