This is a post just for sealing light-colored marble, light granites, limestone, and other light-colored cool-tone stones.
My post on all-natural oil-based sealers for stones focuses on walnut and other non-toxic oils that work best on dark-colored, medium-tone (or beige-toned) stones since they do darken and yellow the stones slightly.
There is no 100% natural, 100% toxin-free, or zero-VOC sealer for white and light-colored stones. This should be considered early on if it’s a new build for someone chemically sensitive.
Light-colored stones are also much more likely to be porous compared to some darker-colored stones that can be naturally dense enough to not require a sealant.
Manufacturers of natural stone countertops usually recommend a penetrating or impregnating sealant every few years (depending on the type of stone, the use etc).
These sealants do not fully disclose their ingredients, but I have dug into the literature to see what is likely in them.
These three sealers are ones I have tested, researched, and compared, and are the safest, lowest offgassing options out there right now.
This post contains affiliate links. Upon purchase, I earn a small commission at no extra cost to you.
1. Sealer’s Choice Gold
Aqua Mix Sealer’s Choice Gold by Custom Building Products is a water-based sealant for natural stone. It’s low odor, low VOC and has been a favorite among the chemically sensitive.
What are the Ingredients
These types of sealants commonly contain proprietary fluoropolymers as the main technology along with alcohols and ethylene glycol mono-n-butyl ether. More on those ingredients below.
Microban was Added…
This product hasn’t always had Microban – that was added more recently. The company would not disclose which chemical Microban refers to in this instance, but by looking through the Microban website it’s most likely nanosilver. It could possibly be zinc pyrithione.
I don’t think it’s a good idea, in the long run, to add nanosilver to products, but in terms of the actual exposure to the individual homeowner, I don’t consider nanosilver to be very harmful here.
Testing a Sample
I tested this sealant on previously unsealed quartzite. It’s fairly low odor when wet (though not extremely low odor). I did find that by the next day I personally could not pick up any offgassing. I can see why it has been a top choice among the chemically sensitive.
All chemically sensitive folks should test out a sample before proceeding to seal a slab in their house.
Where to Use it
On light-colored, cool tone stones that would be discolored by natural sealers (like walnut oil), including white and grey marbles, light grey granite, travertine, and limestone. (Of course, it works well on porous dark-colored stones as well, I just prefer to use a natural oil-based sealer on most dark natural stones).
You can use it on unsealed and previously sealed countertops that are due for re-sealing. As well as light-colored stone tiles in the shower, bathroom, backsplash, and floors.
Where to Buy
2. Granite Gold Sealer
Granite Gold Sealer is another water-based sealer that is low odor and low VOC.
What’s in it
While these two sealers probably use similar technology, the two smell quite different.
Still, it likely has the same base of ingredients: proprietary fluoropolymers as the main technology along with alcohols and ethylene glycol mono-n-butyl ether. More on those ingredients in their own section below.
It’s difficult to quantify which of these two is better for folks with chemical sensitivities and because it’s hard to compare these two objectively. You may want to test both options – sensitivities are very individual.
I personally found this one a little harsher when wet but as soon as it was dry (which was very fast) I found it to be great.
Where to Buy
3. Stain-Proof Stone Sealer (Formally META-CREME)
This product uses a different formula than the first two. This is a water-based silanes and siloxanes impregnating sealer.
It’s similar in odor and VOC levels to the first two. All three are low odor compared to solvent-based sealants and all three could work for chemically sensitive folks after testing for individual tolerance.
(If you have a really wet area like the base of the shower, the company recommends this product for porous tiles in that area).
What’s in it
The company provides a full (or almost full) ingredients list in their SDS: octyltriethoxysilane, triethoxytridecafluorooctylsilane, decamethylcyclopentasiloxane, alcohols C12-16 ethoxylated, alcohols C12-14 ethoxylated, dimethylsiloxane/[(2-aminoethyl)amino]propylsilsesquioxane, octamethylcyclotetrasiloxane.
I certainly did find the odor mild and fairly quick to offgas, but I did not test this at the same time as the two above to compare it to those.
When testing it for durability I wasn’t that happy with it. It didn’t hold up well to marring from vinegar and it wasn’t easy to touch up those areas. I have some photos of that testing in my natural stone sealer post. But that is not unique to this sealer, calcium-rich stones like marble, travertine, and limestone are very vulnerable to acid etching. It was interesting how well the natural walnut oil protected against vinegar since as far as I know, all chemical sealers cannot protect against acids.
Where to Buy
- Organic Lifestyle in Canada
- Various online and instore locations in the US
Composition of Fluoropolymer Based Stone Sealers
What’s Really in Them?
We don’t have a full disclosure of ingredients from any company making a fluorolopolymer based stone sealant as far as I know. The following is based on piecing together disclosures from various companies and from looking at patents.
A fluoropolymer in stone sealants could mean any of the following:
- polyvinylfluoride (PVF)
- polyvinylidene fluoride (PVDF)
- polytetrafluoroethylene (PTFE)
- polychlorotrifluoroehtylene (PCTFE)
- perfluoroalkoxy polymer (PFA)
- fluorinated ethylene- propylene (FEP)
- polyethylenetetrafluoroethylene (ETFE)
- polyethylenechlorotrifluoroethylene (ECTFE)
- chlorotrifluoroethylenevinylidene fluoride
- perfluoropolyether (PFPE)
- perfluorosulfonic acid (PFSA)
- Based on Patent
The ingredients probably look something like this:
- Ethylene glycol mono-n-butyl ether
- Fluoropolymer aka mixed perfluoroalkylethyl phosphate salts
- Isopropyl alcohol
- Source Pharos
Do you Really Have to Seal your Countertops?
Countertop sealers last around 2-5 years. Sealers break down over time. The resin is degraded by cleaning products and by general use.
Porous stones are more susceptible to stains and will require sealing more often (1-3 years). Check the density and integrity of the past sealant with a simple “water drop test”. Each stone is different, and sealers and quality of application vary – you have to do a water drop test to determine if or when to seal your stone.
Water Drop Test:
- Stone must be clean and free of dust
- Place a single drop of water (quarter size) on the stone
- Length of time to absorb: <1 minute porous; >1 minute non-porous
- Perform three tests for the first 2,000 ft2 and at least one for each additional 3,000 ft2
Source MCM Natural Stone Inc and ASTM F-3191
Be sure that you are not using cleaning products that etch the stone and break down the sealants (no vinegar, no hydrogen peroxide, etc), here are non-toxic cleaning and disinfecting products for real stone.
Adding more Protection
You can also add a wax to polish your stone countertop. A brand like Rock Doctor makes a carnauba and mineral oil-based wax polish that works with their flouropolymer water-based sealer. Unfortunately, their polish also has added fragrance to it though.
Alternatives to Using These Synthetic Sealants
- Use a dense stone that does not require any sealant. Look at Ubatuba, Black Galaxy, Absolute Black or Blue Pearl granite, Slate, some Quartzites, and other dark-colored dense stones. Dense stones normally shouldn’t be sealed or may only need one application of sealant.
- Use walnut oil to seal a medium to darker colored or warm-toned stone (see how well this performs here).
- Choose a countertop that doesn’t need a sealant at all like quartz, Dekton, and others in the main countertop post.
Related post: The most affordable non-toxic countertops
Corinne Segura is a Building Biologist Practitioner with 7 years of experience helping others create healthy homes.