A macro sampling chamber equipped with mid-infrared (IR) focal plane array (FPA) detector was used to examine chemical treatments of cotton fabrics. Conventional IR methods typically examine individual points in a sample, while the FPA detector provides spatially resolved spectra that can corroborate chemical treatment and its distribution on the cotton fabric. Characterizations of three distinct treatments are presented: non-durable treatments of N, N-diethyl-3-methylbenzamide (DEET), an active ingredient in commercially available insect repellents, a phosphazine-based fire retardant, and fabric treated with deuterated water. All chemical treatments examined in this study exhibited distinct vibrational bands that could be used as markers of the fabric treatments. Our results suggest that the mid-IR FPA detector can be used to characterize fabric treatment uniformity and provide qualitative confirmation of fabric chemical treatment.