You have all the labels available at http://world.openfoodfacts.org/labels but you still should of course exercise caution and read the packaging.

http://world.openfoodfacts.org/label/vegan http://world.openfoodfacts.org/label/vegetarian

Power tip: you can actually look for several criterias: eg: http://world.openfoodfacts.org/label/vegetarian/label/organi... or http://world.openfoodfacts.org/label/vegetarian/category/puf...