A fiberglass-reinforced polymer blend with a new-generation name retardant is Studied with multienergy synchrotron X-ray tomography to assess the blend homogeneity. Relative to other composite materials, this sample is difficult to image due to low X-ray contrast between the fiberglass reinforcement and the polymer blend. Also, the glass fibers are only slightly larger than the 3.26 mu m voxels and, due to their high concentration, exist as partially aligned bundles in the polymer matrix. To investigate the chemical composition Surrounding the glass fibers, new procedures were developed to find and mark the fiberglass and then assess the flame retardant distribution near the fiber bundles. Oil the basis of the multienergy imaging across Br and Sb K-edges, the absorbance values were converted to Volume percent concentrations. Besides the basic question of the successful and stable blending of the flame retardant and synergist within the polymer matrix, we are also interested in precipitation reactions that might concentrate or diminish concentrations in the close vicinity of the fiberglass reinforcement. Thus, a procedure was developed to analyze radial concentrations about selected, well-isolated fiberglass bundles. Overall, the results show a nicely homogeneous system to the level or the tomography resolution, 3.26 mu m, with some enhanced concentration near, similar to 20 mu m, the fiber bundles.