This invention relates to stable liquid biuret modified toluene diisocyanates, prepolymers thereof, stable liquid biuret allophanate modified toluene diisocyanates, prepolymers thereof, and to processes for the preparation of these compositions. The stable liquid biuret modified toluene diisocyanates comprise a secondary amine based biuret modified TDI having an NCO group content of about 12 to about 46% by weight.