Liquid smoke, or condensed smoke, is a seasoning agent used to invoke the flavoring of a naturally smoked food. Liquid smoke is created when sawdust and condensation from burning wood are collected and mixed with various acidic compounds. Specific production varies from product to product, and some concentrations contain other ingredients such as sugar and vinegar. 

Due to naturally occurring toxins, liquid smoke has been found to contain carcinogenic compounds. Some tests indicate that it can be genotoxic and resulted in disruptions in animal DNA.

It is for these reasons that it’s advised to consume and liquid smoke or bar-be-que flavored products in moderation.