The invention provides a blowing agent composition and method of making the same comprising mixing carbon dioxide and a co-blowing agent or a blowing agent selected from the group consisting of hydrofluorocarbons, hydrochlorofluorocarbons, hydrofluoroethers, hydrofluoroolefins, hydrochlorofluoroolefins, hydrobromofluoroolefins, hydrofluoroketones, hydrochloroolefins, fluoroiodocarbons, alkyl esters, water, and mixtures thereof. Also provided is a method of making a low density foam using the blowing agent composition, and a biodegradable or biorenewable foam formed from a foamable biodegradable or biorenewable resin composition and the blowing agent composition.
