What is the binding agent for this flooring? I notice a significant rubber smell and am worried it is not safe to breathe.

Most of the smell that comes from our Regrind Rolls and our rubber flooring, in general, is typically due to the rubber material itself. Not necessarily the binder. This smell is not toxic, and our rubber flooring is tested regularly to ensure they are safe for people of all ages. Rubber has a distinct smell, and to mitigate this, we recommend mopping the floor with a mild soap and water solution and installing it in an area with optimal ventilation. You would then let the flooring air dry. You may have to repeat the cleaning steps a few times to truly mitigate the smell.