The Least Toxic Wood Varnish?
I tested all of the “eco” or, healthy low-VOC, floor finishes. I was looking first at the odor and VOC levels as the main comparison point for those sensitive to chemicals.
I take a look at the ingredients and claims, but that can only tell us so much.
I also wanted to see what the finishes looked like and how much they changed the color of the wood.
Each varnish was applied in three coats to oak flooring pieces. Though I didn’t sand the wood as much as you would for floors in a house, I was still able to get some comparison on durability. In reality, it takes years to see the full picture of how they hold up.
Which One is Ultimately the Best?
One of the main complaints of these “green” clear floor finishes is that the lowest odor ones are not always the most durable. That is somewhat true.
I consider Vermont Natural Coatings to be the best mix of low odor and durable. Earthpaint and BioShield should be considered by the most chemically sensitive for their very low odor when wet, but they might not be the most durable.
For Furniture and Woodwork Too
The original focus was on varnishes for hardwood floors but many of these brands can be used on furniture, wainscotting, and other interior woodwork. I mention those in the post as well.
- ECOS Paints
- AFM Safecoat Poly BP and Acrylacq
- BioShield Aqua Resin
- Vermont Natural Coatings PolyWhey
- Earthpaint Aqualine and Easy Safe 1 K
This post is not sponsored. I paid for all of the samples and supplies. At the time of writing, a couple of the companies – ECOS and AFM – have affiliate programs. Upon purchase, I earn a small commission at no extra cost to you.
Lowest Odor When Wet
Earthpaint Aqualine and Easy Safe 1 K
Close second place – BioShield Aqua Resin
Lowest Odor at 24 Hours
BioShield Aqua Resin
Most Invisible Look
BioShield Aqua Resin, followed by AFM Poly BP
Vermeister and Vermont Natural Coatings
Best Mix of Durable and Low Odor
Vermont Natural Coatings
For Hardwood Floors (Clear): AFM Safecoat Poly BP; BioShield Aqua Resin; Vermeister, Vermont Natural Coatings PolyWhey; Earthpaint Aqualine; and Easy Safe 1 K
For Hardwood Floors (With a Stain): AFM Safecoat Duratone + Poly BP; Earthpaint Aqualine and Earthpaint NanoTech
By Odor Level:
When wet: From most mild to least – Aqualine and Easy Safe 1 K, Biosheild Aqua Resin, Vermont Natural Coatings, ECOS, AFM, then Vermeister.
At 24 Hours – they were mostly all at a similar odor level at 24 hours, though I did find Biosheild Aqua Resin had taken first place at 24 hours.
48 hours – at my level of sensitivity I could not really pick up much at 48 hours off any of the finishes. Some had just a slight offgassing and some like Biosheild and Nanotech were odorless to me.
There are folks who are more sensitive and more reactive than me. Please get samples to see which ones are best for you.
1. Vermont Natural Coatings
The top overall pick because it has the best mix of durable and low odor levels of the bunch.
Vermont Natural Coatings is a bio-based polyurethane. This means part of the polyurethane is derived from whey. They claim that the co-binders and solvents typically found in conventional wood finishes and polyurethane coatings are replaced by naturally derived ingredients.
I do find it milder than conventional polyurethane. I have heard others say they found this very similar to AFM Poly BP, but this is clearly a very different formula. The odors are significantly different to me.
PolyWhey Floor Finish is a good option for hardwood floors, bars, tabletops and other large horizontal surfaces. If your project involves vertical surfaces (like bookcases or chair legs), they recommend using the Furniture Finish.
Polywhey floor finish can be applied over a previous oil-based floor finish. (PS their exterior PolyWhey is also known to be the most durable low VOC water-based exterior finish).
- Hydro Lacquer Reactive Sealer with PolyWhey – this gives the look of an oil finish. It can be used on furniture and floors. Certainly a different formula than the floor finish. This has a different odor, milder than the floor finish.
- PolyWhey Floor Finish – their general bio polyurethane floor finish. This is a little milder than a typical polyurethane. It has a more milky smell when a regular polyurethane which has a sharper more acrid chemical odor. When wet, at 24 hours and at 48 hours it was milder than Poly BP, stronger than Aqualine.
- All-in-One Stain & Finish – their Polywhey with a stain included, this is not recommended for floors. This is milder in odor than both the floor finish and the hydro lacquer.
- Hydro Lacquer with PolyWhey is $82.75 a gallon
- PolyWhey Floor Finish and the Stain & Finish are both $77 a gallon which covers 500 – 600 sq ft (one coat)
Where to Buy:
- The floor finishes can be purchased through Walmart. Their furniture finish can be purchased on Amazon.
2. ECOS Paints
Good pick for chemically sensitive folks who don’t do well with polyurethane and don’t need a super durable finish.
ECOS wood finishes (like their paints) are 100% acrylic. Most hardwood floor finishes are polyurethane. This wouldn’t be my pick for floors, as it hasn’t proven to be the most durable option. But for those who do better with acrylic coatings, this can be used on non-floor woodwork. I used it in my tiny house on my kitchen cart and was very happy with it.
You can see a full ingredient list for each product on their website. This is the most transparent of all the brands as all ingredients are listed clearly.
- Interior Satin Clear – only slightly milder than AFM (not that different). At 48 hours there is still a slight sweet smell.
- ECOS Air Purifying Varnish (APV) was stronger when wet than regular ECOS satin, but better than regular satin at 48 hours. At 48 hours could not pick up anything.
- ECOS Wood Conditioner – is milder than the varnishes, but not totally benign.
- ECOS Tinted Varnish – a little milder than the clear varnish (maybe the pigments are diluting it a little).
- ECOS Exterior Satin – not that different from the interior finish. The exterior might even be milder!
- ECOS Interior Satin is $89.95 a gallon and covers 500 sq ft (one coat)
- ECOA APV is $99.95 a gallon
- ECOS Tinted Varnish is $93.95 a gallon
Where to Buy:
- Through the ECOS Paints website.
3. AFM Safecoat
I like this brand because it’s a tried and true brand that has been around for a while.
- Acrylacq, Satin – much more tolerable when wet compared to Poly BP.
- This sealant is not used on floors but it’s a great durable sealer for furniture, cabinets and other interior woodwork.
- Ingredients include: Acrylic polymer, Dipropylene Glycol Methyl Ether, Water, Amorphous Fumed Silica.
- AFM Safecoat Polyureseal BP, Satin – this was the strongest one when wet.
- This is AFM’s main floor finish though it can also be used on furniture. It smelled almost like an acrylic to me, although it’s mainly a polyurethane.
- Ingredients include: Polyurethane Aqueous Dispersion, Dipropylene glycol methyl ether, Water, Acrylic polymer
- AFM SafeCoat DuroTone, is AFM’s wood stain if you want to alter the color of the wood.
- Acralaq or Poly BP (among others) are used as a top coat over it.
- The Cognac which I tested, had a bit of an unexpected smell. I thought it would be milder than it was, but it is milder than the varnishes.
You can also mix the stain into the topcoat which can help provide an even look on woods like oak. You can also get the fumed wood look on white oak with the AFM walnut stain on the wood and then mixed into the Poly BP (or Acralaq).
- I could hardly pick up an odor at 48 hours.
- Acrylacq is $85.90 a gallon and covers approx 350 sq ft (one coat)
- Polyureseal BP is $99.90 a gallon and covers approx 450 sq ft (one coat)
- Durotone is $53-72 a gallon and covers approx 450 sq ft (one coat)
Where to Buy:
- Green Design Center for sure. Talk to Andy who is an expert on AFM products and he can give you or your contractor advice on the application.
Top pick for lowest odor at 24 hours.
BioShield makes two varnishes. Their floor finish, Aqua Resin Floor Finish, is polyurethane-based. The ingredients are listed as alcohol, anti-skinning agent, dispersion of polyurethane in water, micro wax, silicic acid, and silicone.
It can be used on wood, concrete, and cork, as well as wooden doors, molding, work surfaces, tables, floors, stairs, and furniture.
Their Aqua Resin Stain Finish, which is even milder, can be used on children’s cribs, swing sets, windows, doors, and wood furniture (not floors).
The ingredients are alcohol ester, earth pigments, preservative, silica, surfactant, and water.
- Aqua Resin Floor Finish, Clear. It was very mild when wet. It was preferable in my view to Vermiester and ECOS. It was the best of all the options VOC-wise at 24 hours.
- At 48 hours I could not pick up any offgassing.
- Three coats are recommended.
- Although it was slightly less durable than the others, the extremely sensitive will surely want to consider this brand for the very low offgassing.
- Aqua Resin Floor Finish is $189 for 1.32 gallons which covers 700 – 800 sq ft (one coat)
- Aqua Resin Stain Finish is $92 for 1.32 gallons
Where to Buy:
- Green Building Supply, especially if you want to get samples. You can also order directly through the company.
One of the two most durable, but the highest odor option on this list.
Vermeister Zero VOC is a polyurethane that claims to be zero-VOC as you can tell from the name. I tested the Satin without the booster.
The MSDS does list ammonia (which is an exempt VOC).
The booster part of a polyurethane is usually an isocyanate, but in this case it’s a carbodiimide crosslinker.
It was slightly stronger in odor than AFM Poly BP when wet but they were not that different. AFM Poly BP does declare their VOC levels at 100g/l so I’m not sure when this product took their 0 VOC measurement (I asked them when the 0 VOC measurement was taken and got no reply).
They could be measuring the VOCs at different times to get those results. Also AFM does not have ammonia, the exempt VOC.
I could hardly pick up offgassing at 48 hours. So unless you are highly sensitive all that is just nitpicking. At 48 hours I would consider this safe for almost everyone.
Synthetic polyurethane is the standard for floor finishes. In some ways, this was the most durable of all the options here according to my tests (though not by much), and probably the most conventional, especially if you add the booster.
- Vermeister is $129 a gallon which covers 300 – 500 sq ft (one coat)
Where to Buy:
Top pick for lowest odor levels when wet.
Earthpaint’s finishes ranked among the most tolerable in odor and offgassing. If you are applying this yourself or kids are applying it on wood crafts this is a great option.
The Aqualine does not have polyurethane in it, this is a 100% acrylic floor finish. There are no exempt VOCs or solvents.
The Easy Safe 1 K finish is a commercial finish described as a nano acrylic/polyurethane mix. It’s made for wood floors, bar tops, gyms, countertops, restaurant tables, and boats.
Their NanoTech is a wood floor and concrete finish made from nano-sized liquid acrylic resin. It can also be used to block offgassing from a previously laid finish (including many oil-based finishes). It can be used on the exterior as well.
- NanoTech – can’t pick up odor at 48 hours
- Easy Safe 1K Floor Finish – this one I can still pick up at 48 hours – though I found it significantly better than Vermeister and Poly BP. Better than ECOS when wet. Slightly better than Biosheild when wet.
- Aqualine, satin – This was the best of the Earthpaint finishes when wet. It does seem milder than their 1 K, but not sure if that is accurate. I barely could pick up any odor at 48 hours.
- NanoTech in clear is $98.09 a gallon which covers about 400 – 500 sq ft (one coat)
- Aqualine and Easy Safe 1K in clear are both $139.98 a gallon covering 500 – 600 sq ft, and 400 – 600 sq ft respectively (one coat)
Where to Buy:
- Buy it directly through the Earthpaint website.
- ECOS Paints, is a trusted acrylic brand for non-flooring projects. If you do best with acrylic coatings and don’t need it to be super durable go with this one.
- AFM Safecoat Poly BP and Acrylacq – this is another trusted brand that’s been around for a long time. If you like AFM products you should check these out, otherwise they didn’t hit any of the top qualities.
- BioShield (Aqua Resin) and Earthpaint (Aqualine) have the lowest odor, especially when wet. If you have severe chemical sensitivities you should test these. These would also be my top picks for kids’ wooden crafts.
- Vermeister tied with Vermont for most durable (except it was the highest odor). This brand is the most conventional in that it’s a two-part polyurethane, which made it the highest odor, and quite durable. But if I was going to go with a two-part higher odor polyurethane I would go with a conventional brand BONA Traffic or LOBA Invisible.
- Vermont Natural Coatings PolyWhey is definitely my top pick because it’s the best mix of durable and lower odor. My overall top pick for a non-toxic floor finish.
Notes: Results from My Durability Tests:
There was no clear winner in my durability test.
The only one I wouldn’t use on floors myself is ECOs.
Vermeister, Vermont, and Aqualine held up the best in my experiments.
The reason there is no clear winner is that some held up well to some things but not others. And also importantly, my limited experiments cannot replicate long-term wear and tear. I was not able to replicate the problems that I have seen in real-life situations with ECOS on floors, for example.
This is what I threw at them: water drops, wet rag left on, boiling water, wine, whiskey, ammonia, red wine vinegar, urine, alcohol, smashed in blueberries, tumeric.
- 1K and NanoTech have some very slight water circles from water left on until it dried, all passed though.
- All passed: quats (ammonia), wet rag left one, urine 20 seconds, boiling water 1 tablespoon, red wine vinegar.
- Poly BP slightly marred from urine left on for a couple of hours, all the others passed.
- Aqua Resin, Nanotech, then ECOS, were most affected by a turmeric water paste (30 seconds). Poly BP was only ever so slightly affected. Vermeister and 1 K held up quite well, but all were somewhat affected.
- 1 K and ECOS didn’t hold up as well as the others to alcohol tincture, whiskey, and red wine. Poly BP also had some marks.
- Poly BP failed blueberry sauce smashed in. The others passed.
- Vermont and Vermeister held up the best over all followed by Aqualine.
Corinne Segura is a Building Biologist Practitioner with 8 years of experience helping others create healthy homes.