A solid phase extraction method for removing polar tritiated contaminants from tritium-containing waste oils has been developed. The composition of the degradation products present in the waste oil was determined. The results indicated that upon exposure to tritium gas, fragment methyl ketones, carboxylic acids, and lactones were the main polar products of the mineral-based oil oxidation. The nonpolar fragmentation products included n-alkanes, monomethylalkanes, and acyclic isoprenoids and were analogous to those formed during [Formula: see text]-irradiation of the oil. Various polar and nonpolar fragmentation products containing an isoprenoid skeleton were found to be formed via an oxidative/radiation scission of long-chain acyclic isoprenoids.