New Developments in “Green” Building Materials
I’ve been working as a green materials specifier for the last eight years and these are the positive trends in the industry that I have been seeing. While a few trends are partially greenwashing to attend to consumer demands, the trends are overall in the right direction.
My main focus with “green” materials is on the health effects of the end-user, since most people I work with are chemically sensitive, but I do keep in mind the holistic environmental impact of a product.
I myself have environmental sensitivities which has driven me to look closely at the air quality and health impacts of building materials. I often test and compare multiple products across brands.
The greenwashing is strong out there, and transparency is still relatively low in the industry. It remains extremely important for independent bodies to keep companies accountable and to compare products across brands.
Engineered Wood Developments
Soy-based adhesives have certainly established themselves as viable alternatives in the last few years. There are now two big brands of plywood made with soy-based adhesive and it’s more than just a fringe product. Several secondary companies, like cabinet makers, now offer this type of plywood as an option.
This was driven by consumer demand for low or no-add formaldehyde products. Realistically, regular plywood made with phenol-formaldehyde off-gasses to completion quite quickly but the demand for no formaldehyde products is very strong. This is a good thing for those who are extremely sensitive to formaldehyde, since that is really the only group that had challenges with regular phenol formaldehyde based plywood.
Adding “formaldehyde-free” or “no added formaldehyde” is common on many product descriptions now due to this consumer demand. This is the case even if formaldehyde was never used in that product.
In many engineered wood products, MDI glues can be used instead of formaldehyde. I would argue that MDI is not an improvement in terms of its effects on indoor air quality. Most chemically sensitive people would agree.
However, policy shifts like CARB, plus consumer demand, have led to an overall reduction in formaldehyde levels in building materials and therefore in homes. The higher off-gassing urea-formaldehyde is used less and you are not likely to find a high formaldehyde product in new North American homes anymore.
At the same time, we need to push for transparency with these no formaldehyde glues and resins. The term “bio-based” is very vague and often only refers to a small percentage of the product being bio-based.
If you know one thing about flooring trends you probably know that luxury vinyl plank/LVP (or tile) is the biggest thing in flooring right now. In low to mid-range new homes and renovations, vinyl plank is the most popular floor that I’m seeing.
The increase in PVC production takes a big toll on the environment even though the flooring itself does not off-gas VOCs in any significant amount. The most concerning chemical in LVP for the end-user is plasticizers. While phthalates have been removed from almost all brands over the last few years, DOTP, the replacement still has a lot of unknowns in terms of its effect on human health.
While the LVP trend is going full steam ahead, there are a couple of flooring technologies and trends going in a better direction.
Bio-based polyurethane resilient flooring (where a portion of the polyurethane is derived from plant sources like castor oil), is a very good replacement for sheet vinyl flooring. Sheet vinyl is high in VOCs while this type of polyurethane is practically odorless and VOC-free. It contains no plasticizers. An excellent alternative for schools, medical facilities, and trailers.
Another good option for resilient flooring is natural linoleum. Linoleum is making its comeback although it’s not that common. It’s often above budget for a building that was planning on using vinyl sheet, but other than that it’s a great natural alternative.
In wood-based floorings, there is a trend towards no-added formaldehyde or very low formaldehyde resins. For example, Amorim Wise cork flooring is made predominantly with a PET binder, and has extremely low offgassing levels. This is a big improvement over other types of cork flooring which are rather high in offgassing.
Mineral wool has started to take over the market, especially in higher-end homes. Fiberglass is still the norm in lower-end and maybe mid-range homes.
Both types have shown progress with their chemical additives. Mineral wool does not use a flame retardant and the binder, which is usually phenol-formaldehyde, offgases very fast.
All fiberglass insulation brands have switched over to non-formaldehyde binders in the last few years.
At the same time, two-part polyurethane spray foam is growing in popularity in higher-end homes. This insulation has significant off-gassing in my experience and is heavy in flame retardants, mainly TCPP. And because spray foam is usually inside the building envelope I am concerned with the off-gassing levels and flame retardants.
New insulation codes across the US are now making rigid foam almost inevitable on the exterior of the sheathing as well. All three types of rigid foam (EPS, XPS, polyiso) contain chemical flame retardants like TCPP and Polymeric FR. While there is some progress in the blowing agents and flame retardants, there is still a long way to go to get rid of toxic additives.
More unusual insulation types include wool and hemp, which are gaining in popularity but are still establishing themselves. A number of hemp insulation companies have gone in and out of business over the last few years, which does worry me and signals that this product has not been perfected, or the market is not ready for it.
Paint and Coating Trends
It’s certainly unusual to use an oil-based paint in a new build these days. The norm for walls is definitely acrylic-latex paint with water-based alkyd on the trim and doors. And that’s good, because I’m sure everyone knows how strong the solvent odor is in typical oil-based paints.
In the last few years, VOC levels have come down in almost every latex paint brand with just about all brands introducing zero-VOC lines at all price points.
Even the lines that are not zero-VOC, are now usually extremely low in VOCs. This makes it a lot easier to choose a paint from any hardware store or local paint store.
For trim and doors, the newer water-based alkyd paints are not zero-VOC but they are quite low-VOC and offgas fairly quickly. Certainly an improvement over oil-based paint.
Those who are sensitive to chemicals or who just want to go all natural can now access all natural linseed oil-based paint in North America. This paint type has no solvents and is a good alternative for trim and doors.
For those concerned about microplastics from the disposal of paint, there is an alternative. VAE-based paint is still “latex paint” but it’s not an acrylic and does not contribute to microplastic pollution. Farrow and Ball paint is one example. This type is not as common as acrylic paint but is lower odor when wet so it might be a healthier choice for the person applying it compared to even zero-VOC acrylics.
Where I’d Like to See the Industry go Next
For paint, I would like to see more awareness VAE paints because they are lower odor when wet and do not produce microplastic pollution. I would like to see a move away from red list preservatives that almost all paint companies use.
With insulation, I would like to see the complete removal of toxic flame retardants which are currently present in rigid foam and spray foam insulations towards non-toxic and more chemically stable (non-leaching) alternatives. I will keep my eye on the more natural alternative insulation materials and if the companies can scale up.
With flooring, I would love to encourage people to consider alternatives to LVP, like engineered wood flooring, though I don’t see the vinyl trend dying down anytime soon. What we can do is push for safer plasticizers like bio-based options and accelerate safety testing of DOTP.
The movement to lower formaldehyde levels in engineered wood has overall been a positive movement. I think alternative glue technologies need to be transparent with their ingredients so we know exactly what is in them, just how much of the content is bio-based, and how does that impact the VOC levels of the product.
Corinne Segura is a healthy materials specifier and author of the website My Chemical-Free House.