Abstract: Nanocomposites are know to enhance flame retardancy (FR) and result in reduced PHRR compared to the virgin polymer, which is good, but on the other hand the total heat produced is the same as that of the virgin polymer, which means that eventually everything burns. Phosphorous-containing compounds are also used as additives and they reduce flammability. However, like any other additives large amounts have to be used. The advantage of using phosphorous-containing compounds is that they are not hazardous to the environment. So with these facts in mind the objective of this study is to develop a small-scale system that can be used for the preliminary analysis of nanocomposites containing phosphate additives and then study the synergism between nanocomposites and phosphorous-containing fire retardants (FRs) for large samples. This goal was achieved by first developing a high throughput system that was used to evaluate phosphorous-containing additives that are compatible with nanocomposites and do not burn after exposure to a flame. Large samples of the Polymer/Fire retardant/clay systems were prepared using the phosphates that passed the first analysis. The amounts of both the clay and FR were varied. In the second part we investigated the synergism in vinyl ester (VE) nanocomposites. The vinyl ester studied was Derakane 441-400. In the VE/FR/clay systems, apart from varying the amounts of fire retardant and clay, we also investigated the effects of using different clays, varying mixing times and varying the curing conditions to see effect on the clay dispersion in the nanocomposites. In these systems we hope to lower the flammability of the systems and also not adversely impact the mechanical properties. The effect of varying the structure of surfactants on nanodispersion and fire retardancy of clay nanocomposites was also investigated.