There are as many different opinions of what kind of coating should go on a cutting board as there are different kinds of cutting boards. The purpose of this article is not to suggest what can be used but to provide information on a wide number of products that could be used.
It is up to the woodworker to make the final decision based on where the the cutting board will be used.
In the end, the best coating for a cutting board is no coating or finish at all.

If we look at the life of most wooden cutting boards, they begin as new wood with some sort of a coating on them, usually some sort of oil-type coating. During their use they are either used to cut meat, or they are designated to cut other things like fruits, vegetables, breads and other common cutting items. In either case the cutting boards are cleaned regularly with warm soapy water, dried off then left to air dry. This process of constantly washing a drying, in a short period of time will wash off any coating that was originally put on the cutting board.

Since most cutting boards are seldom, or never re-coated after they begin use, what happens is the cutting board develops it's own patina or look that in some cases is similar to what the board was originally coated with. This is now most cutting boards live their life, which can go on for years and years. Cutting boards should be disposed of if they develop any kind of a crack in the wood, or if during their use they subjected to some very deep cuts. These kinds of cuts and cracks can harbor bacteria and pathogens that could cause illness so it is best to eliminate these threats.

Before we get into what are some of the finishes you can use on cutting boards, lets look at the short list of what you should not use, or at least be very cautious in using ....

Coating to be Cautious of and Not to Use
One main point to consider in finishes for cutting boards is ... will the product I use leave hardened coating that in time can chip off? If the answer is yes, then don't use it ... like, Varnishes, Varathane, paints, lacquers, epoxy products and anything else that will hard coated. More on the "what to watch out for list" are products like tung oils, shellacs, danish oils and similar kinds of oil and oil like finishes. These products could potentially be ok, but if they are not rated "food grade" on the labels, we just are not sure what is in them so you are best to select another product for a cutting board finish. Lastly in the do not use category is any kind of animal fat or lard. These can quickly deteriorate on a cutting board and harbor little things none of us want associated with our food. 

Coating That Can Be Used
For most woodworkers the reason to coat their cutting boards is to make the wood look nice, but also to be a food safe product, the question of what coating to use is often a big question. Every kind of coating for a cutting board is some sort of an oil based coating, and they come in a few different categories like nut oils, vegetable oils, seed oils and even petroleum oils.

Hardening Oils and Non Hardening Oils
The truth is, all oils will harden in time, but some can take years or even decades when exposed to air, so in woodworking we break oils down into hardening oil ... those that will harden in hours or a couple of days, and non-hardening ... those that remain somewhat damp for years. The non hardening oils often soak deeper into the wood over time and these are oils that need to re-coated every few years.

Either hardening or non-hardening oils are fine on cutting boards ... and remember, what ever you put on, is likely going to be washed of completely within weeks of constant cutting board use ... which, really is a good thing because eventually a cutting board ends up with no coating at all, which in the end, is the safest.

There seems to be some confusion as to what are hardening or drying oils and what are non hardening oils, which is probably from the fact that some take longer to dry or harden so harder to identify their use. What appears to be more a bit of a guideline is that vegetable oils appear to be more non-hardening while nut and seed oils appear to be more in the hardening group.

Nut and Seed Oils
There are dozens of nut oils available and pretty much any one of them will work fine for a cutting board coating HOWEVER - nut and seed oils are the most prevalent when it comes to food allergies. Peanuts and peanut oil being at the top of the heap. Depending on where the cutting board is going, there is no reason why you could not coat with an oil or seed based product provided you know that it is not going to cause allergy problems to someone, or that they made aware of the situation.

Vegetable Oils
I have been told an a few occasions (like I don't know this) that vegetable oils can go rancid. Yup, I know that, after years sitting in a bottle they can but I don't even know if they can go rancid after they are coated on a cutting board. Regardless whether they can or not, anyone who has a cutting board with rancid oil on it means they have not been cleaning their cutting board. Vegetable oils like Olive Oil are just fine on cutting boards.

Just to give you an idea of the list of oils that could be use ... Almond, Coconut, Cottonseed, Palm, Pumpkin, Soy, Lemon, Avocado, Olive, Grape Seed, Safflower, Sunflower, Orange, Linseed, Poppyseed, Walnut, Pine Nut, Corn, Hemp, Canola, Buffalo Gourd oil, Coriander and many, many more.

Mineral Oil
Many people who make cutting boards use mineral oil on their cutting boards. It can be purchased from most drug stores and is considered a safe product to use. What most people do know is that mineral oil is a by-product of the petroleum industry. The good news is that because of the source of this product there is little or no chance that it can harbor and bacteria. Anyone who has an aversion to any foods that are genetically modified (GMO) would probably not want their cutting boards to be coated with a product like this.

Alternative Finishes
The easiest finishes for cutting boards are to apply an oil finish. It takes a few minutes to apply then left to dry or the oils to soak in overnight and the board is ready to use. An alternative product I have use is Bees Wax. This can be purchased in blocks at many natural food stores. There are also pure bees wax candles available at many places and these could work as well. The process is simple, rub the cutting board with the bees wax until it has a fine layer of bees wax on all sides. To melt the bees wax onto the wood in needs to be heated high enough to melt the bees wax which is around 150 °F (65 °C). Do NOT heat it too high, Bees Wax has a flash point where it will begin to burn at  400°F  (204.4°C) , you do not want this to happen.
Alternatively if you have a small hand torch you can lightly heat the cutting board with the bees wax on it, just until the bees wax melts and bonds with the wood.

Copyright - Colin Knecht