Updated Spring 2020
1. Window materials – Windows made of thermally broken aluminum are the top choice for non-toxic windows. Accoya wood is also a healthy window option. Some vinyl and fiberglass can be considered, though they do offgas.
2. Window treatments – Natural untreated fabric, natural fibre roll down blinds, non-painted aluminum blinds and aluminum screens. Blackout bamboo shades, polyester curtains, hemp, cotton and paper pleated shades should be considered. Avoid PVC shades/curtains, flame retardant and wrinkle-free finishes, and wood and aluminum blinds with finishes that offgas.
3. Window sealing – Polyurethane canned foam is the norm, which does cure quite well. The least toxic option is backer rod.
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Non-Toxic Curtains and Blinds
The best non-toxic window coverings are natural untreated fabric, natural fiber roll down blinds, aluminum blinds and aluminum screens.
For blackout shades, bamboo shades with liners, polyester curtains, hemp, cotton, and paper pleated shades should be considered.
Avoid PVC shades/curtains, curtains highly treated with flame retardants and other chemicals, and wood and aluminum blinds with finishes that offgas.
1. Fabric Curtains
Fabric curtains are usually treated with wrinkle-free chemicals and flame retardants.
Natural fabrics do break down in UV light but are a healthier option. Look for Oeko-Tex or GOTs certified fabrics to guarantee no chemical treatments.
Libeco linen is not GOTS certified but is usually grown without pesticides and the natural colors don’t contain dyes.
Linen options found on Amazon, like the ones in the photo, are either a linen polyester mix or polyester made to look like linen.
2. Blinds and Shutters
Green versions include bamboo roll down blinds that are not treated with chemicals like those from Earthshade and Blinds Chalet.
I got a sample from Blinds Chalet and was happy with them (these really need a backing unless you want just minimal privacy).
Check to see what the backing is and order samples.
Bamboo blinds come in different looks and other grasses can be woven into blinds as well.
Wood Blinds and Shutters
I have not found wooden blinds with a 0 VOC finish since this is so hard to accomplish with something that holds up to UV.
Real wood blinds are also prone to warping. Real solid wood is best used as shutters.
The real wood blinds from Blinds Chalet very very light and thin, I was able to snap it in half quite easily (which I did because it didn’t seem like real wood at first). I could pick up some offgassing.
Faux wood blinds are PVC, but composite blinds can be made of a safer plastic mixed with wood.
Aluminum blinds used to use powder-coated metal which was very safe. You can find some older blinds like this. But currently, all metal blinds in North America, Asia and Europe are made with a polyester-based baked-on enamel finish that does offgas. I have also seen additives, for example, Hunter Douglas ads an anti-static additive to the coating. This may be something like Teflon, which would offgas as well.
You can find brushed aluminum blinds with no paint or coating, like those from Earthshade. At some retailers, brushed aluminum does have a coating.
3. Between the Glass Blinds
Between the glass is a really cool option that eliminates the worry of offgassing. Here is an example from Pella.
4. Window Screens
Conventional screens are very smelly at first. They can be left outside to offgas, or aluminum screens can be used instead. Marvin is one brand that makes aluminum options.
Non-Toxic Blackout Shades
1. Bamboo Shades Blackout Liner
2. Polyester Blackout Curtains
Polyester with No PVC will work for many. If you can wash and or air them out first that will help:
West Elm 100% polyester curtain liner is an extra layer of polyester that goes under their other curtains, no PVC or foam. They still have that new fabric smell but will air out with some time. West Elm has been improving their eco credentials. Someone sensitive to chemicals did well with these.
These Eclipse polyester curtains from Amazon do not contain flame retardants, can be washed and aired out and should be tolerable after washing and airing for most people.
These Sleep Well polyester curtains do not guarantee no flame retardants, but they do claim no chemical fabric coatings. They are 100% polyester and free of PVC. They are washable. You can remove that new fabric smell by washing. Some have reported these having no smell and others more sensitive still can pick up the new fabric smell.
3. 100% Blackout Shades
Earthshade makes eco blackout shades and rollers that are probably the safest ready-made option on the market.
The blackout roller shades do contain 35 ppb formaldehyde which is produced when pressing the polyester sheets together to laminate them with heat.
The shades have also been processed with bleach. Those are the only two treatments of the fabric.
Generally, my recommendation on formaldehyde (as long as it’s not urea) is to give it 3 months of offgassing. When installed with a proper blackout system these will get you the most light blocking of the list.
4. Something Simple for Light Blocking
Another option to consider is this paper black pleated shade – the company claims in an email they do not give off any hazardous chemicals (I bought the natural color version of this – it has a slight toxic smell and needs to be offgassed only for a short while).
They are not that great at blocking light compared to the other options and you will need to double them up to make a bigger difference. But these are super inexpensive, easy to install quickly, and worked perfectly in my tiny house.
5. DIY Hemp Curtains
Another really safe option (truly the safest) would be to make your own blackout curtains with pesticide-free hemp fabric.
Though it’s difficult to make traditional looking curtains from this thick, not very flexible fabric.
6. Cotton Room Darkening Curtains
IKEA Room Darkening Curtains are made with 100% cotton are somewhat light blocking.
They should be washed or aired out before using.
Avoid: vinyl roller shades and vinyl mini-blinds, PVC and conventional blackout curtains.
Non-Toxic Window Frame Options
The top choice for green non-toxic window frames is aluminum (thermally broken). Accoya naturally treated wood can be considered another top choice, though wood is more difficult to upkeep.
Fiberglass and Vinyl are the next best choices – they do offgas, but some brands will cure quite quickly or be low enough emissions to not cause any issues.
Non-Accoya wood is treated with pesticides, insecticides, and fungicides and it’s prone to warping and water damage. Let’s look deeper:
1. Metal Window Frames
Aluminum windows are the healthiest, safest option. It is what I used in my tiny house (pictured above). On the interior, I added wood framing trim. You can also use decorative moldings around the windows.
What is used in the windows as a thermal break is blocked by the glass and metal so there is no need to worry about much offgassing. Thermally broken aluminum windows are all aluminum with polyurethane inside.
Non thermally broken aluminum windows are not a good idea to use as they conduct heat and cold and easily condensate. Aluminum clad means there is an exterior of aluminum which usually has wood inside.
The most extremely sensitive clients can pick up the seal, PVC glass stop and some glues used.
The finishes I have seen on aluminum windows are baked-on enamel, resin paints, powder coated and anodized. Some baked-on enamel finishes and paints can offgas, the other two are considered safe. The gaskets are made out of rubber or PVC.
2. Wooden Window Frames
Accoya wood used in some window brands uses a non-toxic process called acetylation to naturally provide rot resistance. They use no chemical fungicides or mildewcides and they claim this process helps to obtain less shrinking and swelling than most solid wood windows. Loewen is one of the brands that uses Accoya and allows you to choose your paint brand.
You could go with totally custom made wood windows to avoid fungicides/pesticides, but they are more expensive and you still have to consider what kind of sealer you can tolerate on the inside and outside. For an exterior sealer see my post on paints and sealers.
Problems with Wooden Windows
All wood (through and through) windows are not a good idea as they do not hold up well to moisture in the long run, Accoya wood claims to have solved this problem.
You can also consider ones that are wood on the inside and a more weather resistant material on the outside if you like the look of wood inside. Consider also the glue that is used in conventional wood windows could be irritating for the sensitive person.
Chemical Wood Treatments
Marvin’s wood windows (which have aluminum on the exterior) are treated with TimberTreat pesticide, tebuconazole, and propiconazole fungicides, an unlisted insecticide and mineral oil. Pella and Anderson also make wood windows that are treated with the same or similar chemicals (they are also aluminum on the exterior).
3. Fiberglass Window Frames
Fiberglass offgasses VOCs and some sensitive people do report reacting to it. Though it may be tolerable for some. Some types and brands are better than others (in terms of offgassing) and this could result in a preference of fiberglass over vinyl or vice versa.
Marvin’s Ultrex was not tolerated by the very sensitive though some less sensitive have done well with it. Marvin has two different kinds of fiberglass, one has an acrylic component and one has a polyurethane component. You may find them to be different – with the polyurethane one being better tolerated. Pella fiberglass is tolerated by some sensitive folks.
Kolbe has their own fiberglass called Glastra which is mixed with another polymer (plastic).
4. Vinyl Window Frames
Vinyl is generally not healthy, but since this is a hard plastic, many very sensitive individuals report tolerating it. I did not pick up any offgassing on the vinyl windows I tested (and used in a little camping trailer).
I can pick up the offgassing in some of them used in apartments under one year old. Others have reported reacting with new ones, some let them offgas for a while before installing. Personally, with a bit of time to offgas, I find these to be good. Better than fiberglass, but not as good as aluminum.
Fibrex is a PVC and wood composite made by Anderson which some sensitive folks have reported being too high in offgassing for them.
Vinyl components can be used in any window frame type. Look into the gasket, window stops, jamb liners and tracks which can all be PVC. I have seen some companies (like Alpine), replace the PVC stop with aluminum. More details on Alpine (which makes fiberglass and vinyl windows) and other low toxin “High Performance” windows in this post on Passive Houses.
What are High-Quality Trusted Window Brands?
High-quality window companies recommended by architects include: Marvin, Kolbe, Anderson, Pella, and Wasco. Alpine for High-Performance windows.
Are Gas-filled Windows Non-Toxic?
Windows filled with argon or krypton gas have a higher insulative value and both gasses are considered non-toxic.
Are Low-E Coatings Non-Toxic?
The two main types of Low-E coatings are both non-toxic. The”soft coat” which is a mechanically applied silver coating that is within a double pane window system. You will have no exposure to the silver. A “hard coat” is a layer of tin oxide that is applied while the glass is still hot. The tin is a more integral part of the glass in this case, and is therefore not a risk.
Sealing Around Windows
I have a post on caulking that goes into more detail.
Sealing Around the Frame
Plastic backer rod (polyethylene) can be used to seal around windows. This is a non-toxic and odorless alternative to polyurethane canned spray foam.
Many people do tolerate the canned spray foams after some offgassing (give it 24 hours to cure or more). Great Stuff is a common one to find easily online and in stores.
Handi-Foam is another brand, that is certified with Greenguard Gold for more assurance (but I cannot tell the difference between the two).
Wool is another option if you are sure you won’t have moisture issues around windows. I prefer not to have wool around windows.
For zero-VOC window flashing use TYPAR AT. They do not recommend this being used in the rough openings, and it doesn’t fit all building codes.
Corinne Segura is a Building Biologist Practitioner with 6 years of experience helping others create healthy homes.
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