When the term "food safe finish" is applied to any store purchased cutting board it usually means that mineral oil has been applied to the board. USP-grade mineral oil is safe throughout its life and the cheapest pure food-grade oil on the market. This oil, as well as all good cutting board seasoning, repels liquids, oils and food particles and fills the wood pores.
Natural oils such as walnut, almond and coconut oil/butter do not turn rancid as easily as do vegetable and olive oils but can leave a slight taste to foods that are prepared on the cutting board. If anyone in your home has allergies to nuts or nut products, this is not the type of cutting board seasoning you will want to use.
To obtain a tougher finish try beeswax. Although beeswax is often added to nut oils and mineral oil to make the wood surface water resistant and protect the wood from use and wear, it is not waterproof. It does, however, leave a sweet gentle fragrance and a nice smooth feel to the wood surface.
A topcoat of beeswax sits on the surface of the wood and fills in the pores and gaps left behind when the thin oils soak into the wood. Thus, it helps to keep contaminates such as bacteria, and moisture from infiltrating the wood surface.
To apply an oil simply pour it into a little microwave-proof dish and warm it a little. Wipe it on the cutting board, using a soft clean cloth. Be sure to go along the grain. Let the oil seep into the wood for 15 to 20 minutes, then wipe off the excess. This oil application treatment will need to be done four or five times. After the last application, allow the board to dry for six hours before removing the excess oil. This allows the oil to harden and oxidize. Re-oil the cutting board every one or two weeks or when it looks dry so it will not crack. If using beeswax as an additive, add a small amount of beeswax to the oil before you microwave it.
If you wish a beeswax topcoat, polish the surface of your cutting board with the soft paste and a soft clean cloth. Apply as you would use shoe polish, buff off the excess and buff it to a shine after the wax has dried.
Some chefs do not rub oil into their cutting boards; they just have a ball of beeswax nearby and rub the board with it after proper cleaning and sanitizing.