Halalan toyyiban merely means allowed and permissible for consumption with relation to Syariah law as long as they are safe and not harmful.
The opposite of halal is haram/ non-halal which means forbidden and prohibited.
Any food or drink which lies within the grey area and does not fall clearly under the Halal or non-Halal category is classified as ‘Syubhah’, alternatively called questionable or dubious. In this category, until the status becomes clear,
Muslims should avoid consuming Syubhah food or drinks.