Though exciting, a concern for these gels was raised from experiments that showed TMU slowly evaporates from the gels, making them potential environmental pollutants. This is confirmed by the DSC scan in Figure showing the boiling off of TMU at ~185° C. Appropriate toxicological investigations of TMU's environmental effects are lacking, but hopefully future experiments will reveal that its effects on wildlife in general and on humans in particular are less severe than DEHP. For now, however, this cannot be concluded. Nevertheless, some specialized applications for the PVC-TMU Gels may be envisioned, especially if they are coated with a polymer film insoluble in and impermeable to TMU.