Flammability and Volatility Thought Exercise

There is a beaker containing a mixture of 3 different carbon rich compound in liquid form. These compounds can all be oxidised via exothermic reactions. What would be a reason why one liquid is not flammable?

Volatility refers to how readily a liquid can vaporise. To be flammable, a material must enter the vapour phase so it can react with oxygen. To begin, one of the substances may not evaporate as the conditions for said evaporation may be insufficient e.g the temperature may be too low.

Another potential reason may be that the vapour space above the liquid mixture may be dominated by the other 2 materials in their vapour form, so the 3rd material may not have many/any vapour phase molecules formed.