The materials inside your home directly affect the air quality of the space where you spend most of your time.

Adhesives, sealants, engineered wood products, paints and flooring are where most of the VOCs, or Volatile Organic Compounds in a home actually come from.

In this episode, I share which VOCs to know about, where they show up in a typical home, how to specify low-tox alternatives, and how to make sure what you specified is what actually gets installed.

Listen to the episode now.

Hello! This is Episode 428. This is Way #28 of the 44 Ways to Create Your Sustainable Home series, and we’re continuing through Section Six: Choosing Materials, Fixtures and Finishes.

In this section, I’m covering specific criteria for choosing materials and products for your home. We’ve talked about choosing for longevity and durability in Episode 426, and choosing for a low carbon footprint in Episode 427.

Way #28 is: Choose for Low VOCs and Natural or Low-Tox Ingredients.

Given how much time we spend in our homes, the quality of our indoor air becomes super impactful on how our home feels. There’s also the increasing susceptibility people can have to toxins, as well as personal values that drive them to make low tox choices in other areas of their lives.

VOC stands for Volatile Organic Compound. VOCs are carbon-based chemicals that easily evaporate at room temperature and become part of the indoor air in your home. They’re released by a wide range of building materials, finishes, adhesives and furnishings, often during and after construction, and particularly in the first months after a home is completed or a renovation is finished.

You may have noticed a distinctive smell in a newly built or freshly renovated home. That’s largely VOCs off-gassing. The concentration is typically highest in the first six to twelve months, and then reduces over time. But some materials continue to off-gas for years, and the cumulative load from many products in the one space is what creates indoor air quality issues over the long term.

I covered indoor air quality in Way #9, Episode 409, so if you’d like to go deeper on the health side of this, that episode is also worth revisiting.

Formaldehyde is one of the most common VOCs in residential construction, and one of the most concerning. It’s classified by the International Agency for Research on Cancer (IARC) as a Group 1 carcinogen, meaning there is sufficient evidence that it causes cancer in humans. 

The main sources in a home are engineered wood products: standard MDF, particleboard, and some plywood products use urea-formaldehyde adhesives to bind the fibres together, and formaldehyde is released from these products over time. In building products, it’s also present in some adhesives and in some conventional paint formulations.

Benzene is another IARC Group 1 carcinogen found in paints, solvents, and adhesives. Toluene and xylene are also commonly found in conventional paints and varnishes, and are respiratory irritants at typical indoor concentrations. These are the compounds that give solvent-based paints their strong smell.

4-PCH, or 4-phenylcyclohexene, is a VOC associated with carpet. It comes from the styrene-butadiene latex backing used in many synthetic carpets, and is the distinctive ‘new carpet smell.’ It’s a known irritant and one of the reasons people with sensitivities often react to freshly installed carpet.

Internal and external paints can contain VOCs to assist with their viscosity, application and drying speed. Most mainstream paint brands now offer low-VOC and zero-VOC ranges, so discuss this with your team. 

You can also source mineral paints, or chalk paints, lime washes and other types of natural paints, which have no or very low VOCs, but they can produce quite a different paint finish to acrylic and oil-based paints.

Adhesives and sealants can be a higher source of VOCs. Flooring adhesives, contact cement, construction adhesives, and some sealants can carry much higher VOC concentrations than paint. If you’re replacing flooring and an adhesive is involved, or if significant joinery or fit-out work is being done with contact adhesives, check the specifications and what options are available to you.

Formaldehyde has long been used in MDF and similar wood-based panels as part of the resin binder system that holds wood fibres together. 

As an alternative, you can specify an E0 rated board. In Australia, engineered wood products are rated for formaldehyde emissions: E0 is the lowest emission rating, E1 is standard, and E2 is the highest. Europe has recently increased its restrictions from E1 board to now only allowing E05 board, which halves the formaldehyde content.

Flooring is another significant category. Laminate and hybrid flooring and many vinyl products can carry VOC load from both the surface material and the adhesives used to install them. Solid timber, tile, and polished concrete are generally much lower in VOC content. Synthetic carpet releases VOCs from both its fibres and its backing. Natural wool carpet is considerably lower in VOC content and is worth considering in spaces where carpet is preferred.

Unfortunately, just because it’s labelled ‘natural’ doesn’t mean it’ll always be low-tox or low VOC. Some natural products such as hemp or wool can have binding agents added that increase their VOC content. 

It’s not always the case though, and there are loads of natural options out there that are a much more sustainable choice, often the same price or only marginally more expensive than the synthetic option, but they have a more varied finish to them, or will change their patina over time.

It’s actually quite insane how many synthetic products are the promoted or preferred option to use in your home. Wartime factories used to supply wartime munitions, chemical weapons and military materials were, post-war, redirected to produce building materials at scale, to assist with the massive rebuilding efforts required and housing needs of returning troops. They suddenly became standard products, and in the process, introduced a massive chemical load into our homes.

The Safety Data Sheet (SDS), or Material Safety Data Sheet or MSDS, is a document manufacturers are legally required to produce for products that contain hazardous substances. It outlines what hazardous chemicals are in the product and at what concentrations. 

For many building products, you can find this Data Sheet on the manufacturer’s website, often in a section labelled for architects or professionals, or you can request it directly. It can be a useful document for quickly understanding what’s actually in a product.

In this Episode, I cover:

• What VOCs actually are, why they matter in a home, and how long they typically off-gas after construction
• The specific VOCs to know about and where each one shows up in a typical build
• Where the biggest VOC opportunities sit in a home: paints, adhesives and sealants, engineered wood products, flooring and carpet
• The alternatives worth considering: low-VOC and mineral paints, E0 board for joinery, solid timber and polished concrete flooring, and natural wool carpet
• Why ‘natural’ on the label doesn’t automatically mean low-tox or low VOC, and what to check for
• How wartime chemical factories quietly became residential building supply chains, and why that matters for what’s in your home
• Third-party certifications and rating systems worth trusting
• How to use the Safety Data Sheet (SDS/MSDS) to understand exactly what’s in a product
• Whether a Building Biologist or specialist Interior Designer may be a helpful part of your project team
• Why what you specify and what gets installed can quietly diverge on site, and how to protect against that

Plus a whole lot more.

LISTEN TO THE EPISODE NOW.

RESOURCES:

Episode 409, on improving your indoor air quality >>> 44 Ways #09

Episode 423, on choosing appropriate insulation >>> 44 Ways #23

Episode 256, on choosing building materials >>> Choosing Building Materials

Product sustainability certification >>> Global GreenTag

Living Building Challenge ingredient transparency >>> Declare

A free guide to simplifying sustainability across research, planning, design, materials, and building, from Amelia Lee’s 30+ years in residential design and construction >>> 44 Ways to Create a Sustainable Home

Access the support and guidance you need to be confident and empowered when renovating and building your family home inside my signature online program >>> HOME Method