The proposed study would determine the feasibility of producing a nonporous, moisture-vapor-permeable polymer film, as an absolute barrier to pathogenic microbes. Five homologous, amphipathic polyurethanes will be synthesized with increasing hydrophilic content, and used to cast elastomeric, pinhole-free films with a range of inherent moisture vapor transmission rates ( MVTR ) and thickness. Model permeants, comparable in size to human viral pathogens, will be used to measure transport rates in a diffusion cell, as a function of hyrophilicity and film thickness. Results will be used, together with the measured relationship between MVTR and thickness, to design a film and fabric coating with a high level of comfort when used in proximity to the skin. Very hydrophilic/water absorbing films will also be prepared with an internal virucide (e.g. nonoxynol 9). Additive-containing films will be used to determine if films permeable to viable microbes, through the use of antimicrobials combined with the polymer before film casting. Antimicrobial-containing films will be tested for their ability to inhibit growth of selected microbes on culture media. In Phase II, low-cost antimicrobial BBFs will be developed for use in a variety of infection and contamination control products for healthcare workers, biotechnologists and the general public.