I have an intolerance for E 282 (calcium propionate) - is there any way I can find out if this is contained in foods if the E numbers are not displayed in the contents description on the packaging?

A. Hatton, United Kingdom

Calcium propionate is a salt of the propionic acid. Propionic acid can also be found naturally in some kinds of foods, like the Emmental cheese( Swiss cheese), it occurs while cheese maturation.
Calcium propionate and other salts of the propionic acid are food additives, which work as a preservative. Until today the authorized uses are confined to a narrow group of very specific foods: It is mainly used in bakery products, like pre-packed bread and fine bakery ware, which are susceptible to mould.
All food additives approved in the EU have been assigned an “E number”. Food additives have to be labelled mandatory in any case in the list of ingredients either by their E-number or their specific names. (E280 propionic acid, E281 to E283 sodium-, calcium and potassium propionate). If the list of ingredients does not include one of this substance is not added to the food product.
Food additives are regulated by several EU directives, the Framework Directive 89/107/EEC, the Directive 95/2/EC on additives other than sweeteners and colours, and further directives on other classes of substances.

General information on food additives (rules on labelling of additives, intake, etc):
http://europa.eu.int/comm/food/fs/sfp/addit_flavor/additives/index_en.html