**Ecos paints has a nontoxic, No VOC & allergy free chalkboard paint which would be food safe. Or you can put a clear nontoxic coat over regular chalkboard paint. I'm replacing the tile backsplash soon, never finished!
furniture grade plywood with a edge band. painted it with chalkboard paint using a slightly rough sponge roller. let it dry, then lightly sanded it down, defining the mottled quality of the paint. then finished it by sealing with paste wax.