An oil-in-water emulsion that is environmentally friendly and also exhibits antimicrobial activity is provided. More specifically, the oil phase of the emulsion includes a botanical oil derived from a plant (e.g., thymol, carvacrol, etc.). Because the botanical oil tends to leach out of the emulsion during storage and before it is used in the desired application, a water-dispersible polymer is also employed in the aqueous phase of the emulsion to enhance long term stability of the oil and, in turn, antimicrobial efficacy. Without intending to be limited by theory, it is believed that the water-dispersible polymer can effectively encapsulate the botanical oil within the emulsion and inhibit its premature release. Once the emulsion is formed, water can then be removed so that it becomes a substantially anhydrous concentrate. In this manner, the water-dispersible polymer will not generally disperse before use and prematurely release the botanical oil. When it is desired, moisture may simply be re-applied to the concentrate to disperse the polymer and activate the release of the botanical oil. Of course, to provide the optimum degree of biocompatibility, the water-dispersible polymer is also a “biopolymer” that is biodegradable and/or renewable.