Lifetime of the epoxy system diglycidil ether of Bisphenol A (BADGE n=0)/m-xylylenediamine (m-XDA) was calculated by thermogravimetric analysis. The FlynnWall-Ozawa method is used to determine the activation energy of the reaction. Experimental lifetimes in the range of 60-300 degreesC vary from 1.41 10(9) (2682 years) to 3.35 10(-4) min. This isoconversional method is not appropiate to calculate lifetime prediction because of high errors. Scaling factors were determined using the ratio of two reaction rates.