A new list of approved smoke flavours is being drawn up
The European Food Safety Authority (EFSA) says one of the flavourings used to give smoke flavour to meat, cheese or fish, may be toxic to humans.
The authority looked at 11 smoke flavourings commonly used in the European Union.
It says several of the flavourings are dangerously close to levels which may cause harm to humans.
The European Commission will now establish a list of smoke-flavouring products that are safe for use in food.
The smoke flavourings are products which can be added to foods to give them a "smoked" flavour, as an alternative to traditional smoking.
EFSA says it "cannot rule out concerns" about a flavouring called Primary Product AM 01, which is obtained from beech wood.
The wood particles are burnt under controlled conditions and the hot vapours are dissolved in a solvent.
The Panel says the use of the substance "at the intended levels is a safety concern".
Klaus-Dieter Jany, the chair of EFSA's expert panel on flavourings (CEF Panel) said: "The Panel based its conclusions on the limited data which are currently available as well as conservative - or cautious - intake estimates.
"The Panel expressed safety concerns for several smoke flavourings where intake levels could be relatively close to the levels which may cause negative health effects.
"However, this does not necessarily mean that people consuming these products will be at risk as, in order to be on the safe side, the consumption estimates deliberately over-estimate intake levels."
A spokesperson for the Food and Drink Federation which represents smoked food manufacturers said: "We shall be working with FSA and the European Commission in the coming weeks to consider how smoke flavourings may continue to be used safely, noting EFSA's previous statements in respect of smoke flavourings that their safety is relatively high compared to traditional smoking methods."