Sustainable Building Forum

The only wood finish that is natural, non-toxic and a great reviver is 'Shellac.' A major benefit to using shellac is its natural ability to amalgamate to any previous finish, providing it is clean of wax and grease. Shellac will slightly fill cracks and scratches to make them less visible. It will bring the depth of the wood back to life as it enhances the grain like no other finish. It can be brought pre-mixed or in its natural form, from its natural form you will need to dissolve the flakes in pure alcohol or methyl hydrate. Do not mix more than you need as it has a shelf life of 6 months when mixed. It is available at most hardware stores and can be applied with a lint free cotton rag. Learn more at http://www.ptoone.com (http://www.ptoone.com)

Another natural, non-toxic wood finish is pure tung oil.  Granted, I haven't tried shellac myself so I can't compare the two, but tung is another eco-friendly option.  This is a site that I found sells it without any additives and has a lot of good info on how to use it: http://realmilkpaint.com/oil.html.