Some ingredients such as additives have an identification number which is the E number. The 'E' means that the EU (European Union) has approved the additive. The number is an identification number issued by the EU that is specific to each additive.
Each additive used in foodstuffs must be approved by the Swedish National Food Agency. Only additives which are of value to consumers or which are necessary for handling the foodstuff are approved. Examples of E numbers are E450 and E500 which are two different types of raising agent.