Can you advise on an environmental choice of varnish for a wooden countertop?
I have previously used polyurethane. It's durable but probably toxic.
You’ve probably heard of some of the environmentally friendly wood finishes and simply didn’t know they were eco-minded.
Low-VOC wood finish alternatives are typically finishes made from natural materials such as:
- seeds and nuts
- plant oils
- insect secretions
- mineral pigments
Environmentally minded selectors of materials, products, and finishes spend all that extra time finding low-VOC alternatives for wood finishes because conventional wood solvents release hazardous air pollutants such as: Xylene, Toluene, Ketones, Methanol, and Methylene Chloride.
Here are overviews of some common, low-VOC wood finishes.
Shellac is a natural product made from the secretion of the lac bug, which led to naming lac resin-based finishes “shellac,” after the tiny lac insect. The lac bug sucks saps from the trees it is nesting in, leaving its lac resin behind. Shellac harvesters simply scrape the shellac off the branches causing no harm to the insect or tree, making shellac harvesting a rather eco-friendly process. Shellac is considered a natural polymer-plastic.
Shellac is often referred to as “French Finish” and has been used in furniture finishing since the 18th century. Mastering French polishing can be a little tricky, but if you’re having a professional refinish your piece for you, shellac is an eco-friendly, durable, long-lasting solution.
Water-based wood finishes
Water-based wood finishes are pricier than solvent-based finishes and are less resistant to heat and acids than solvent-based finishes, however on the plus side they evaporate less VOC’s than their conventional counterparts making a healthier environment for you and our ecosystem.
Linseed oil is produced from flax seeds. Linseed oil provides only minimal scratch and stain resistance and is easily penetrated by water and water vapor.
While linseed oil is a great, rapidly renewable product for uses in other products such as linoleum flooring, it wouldn’t be my first recommendation for a wood furniture piece such as a coffee table or end table which may have glasses placed on it that will result in water marks and staining.
There are a number of wax, wood finishes produced from beeswax to vegetable wax; both being natural, non-toxic, environmentally friendly alternatives. Unlike polyurethanes, which form a plastic film, wax finishes have open pores that "breathe," allowing any moisture that does get through to get back out again without pushing off the finish, so your wax finish will never peel or crack.
Wax finishes leave a very natural look on the wood and beautifully highlight grain patterns; however wax finishes need to be continually refinished to stay protected.
Wax finishes are so safe they are suitable for and food surfaces and children’s toys (which may end up in a child’s mouth).
Given that you want to use this for a counter top, I’d go for the non-toxic, food-safe finish options, which are more water repellent.
- Shellac is food-safe approved by the FDA and even often used to coat apples to make then shinier, however it is not the most heat resistant option so unless you’re going to be diligent about always putting hot pans on a coaster, you want towards one of the other options.
- The wax finishes are beautiful for naturally finished counter tops, but if you’re going to prepare food on it know that the breathable finish that allows it to be so beautiful and combat water damage will allow bacteria to seep into it.
- I’d lean towards the water-based finishes if this is for a kitchen counter.
- Tung oil is safe to use as a cutting surface and available in both non-toxic and low-VOC versions, which could be another route to look into as well.
Note: polyurethane is a solvent based finish that will release VOC’s and should be avoided.
Resources for eco-friendly wood finishes
- OSMO Wood Wax finish at ecoHaus a non-toxic, natural wax product
- OSMO Polyx Professional Color Oil at ecoHaus which is solvent free and made from natural oils and waxes
- Vermont Natural Coatings PolyWhey is a low-VOC finish (note it’s not VOC-free) but it’s a water-based finished that’s twice as hard as most typical water-based finishes
- Bioshield is a non-toxic, linseed oil-based finish, safe for food surfaces such as cutting boards and countertops and you can rub it over previous oil-based finishes
- Eco Fin is a new, soy-based, low-VOC finish that can be used on both interior and exterior projects. It’s available at Ace Hardware
Jel’d Stain H2O by Wood Kote is a water-based, low-VOC stain product. Also available at distributors such as Super F Paint.
For more information:
Check our "Buyer's Guide to Clear Finishes" for more on the pros and cons of finish materials.
Also, our backgrounder "Selecting Healthy and Environmentally Sound Clear Wood Finishes" provides additional insight.