ExclusivesThinkingIndoor air pollution: Why we need to reduce emissions from timber products

Eszter Gulacsy, sustainable materials leader at Mott MacDonald, says regulators and industry professionals need to take a systematic look at the issue of emissions from wood products
Content Team1 week ago14 min

The topic of health and wellbeing has been generating much discussion in the built environment sector in the past few years and for good reason. The Global Wellness Institute – as quoted in the Guardian – estimates that the global health and wellness industry has been growing at 6.4% per year since 2015 and this rate is expected to keep increasing.1 

The topic has been popular with all segments of the industry, including architects, owners, occupiers and the engineering community, for its relatability to the main reason buildings exist ­– people.

Health and wellbeing can mean different things to different people. However, its universally positive message resonates with audiences of all kinds of backgrounds.

A progressive approach

The timber industry has been very progressive in showing its contribution to sustainable development and the green building movement. The favourable embodied carbon profile of timber products has been widely publicised and responsible sourcing schemes for wood products have been developed and widely used in construction.

So, what is the main challenge for the industry when it comes to health and wellbeing?

From the point of view of the health and wellbeing consultant, the greatest challenge about timber products in buildings is the issue of indoor emissions, more specifically, formaldehyde.

This chemical compound is widely used in the industry in the binding resins used especially in engineered wood products, but has been classified as a carcinogen.2 The issue is that formaldehyde is emitted continuously from products that contain these resins and therefore various standards and legislation have been introduced to address this.3

Formaldehyde resins come in various forms – for instance, urea-formaldehyde resin has been replaced in many products by phenol formaldehyde, or melamine has been added as a scavenger to reduce emissions.

However none of these modifications have taken away the issue of formaldehyde emissions – they only reduce it. An alternative to formaldehyde-based resin is methylene diphenyl diisocyanate (MDI), which eliminates the issue of formaldehyde emissions entirely.

But this compound raises occupational health and safety issues, as it is a major cause of occupational asthma worldwide.4 Even soy-based alternatives are not the perfect solution, because they use epichlorhydrin – a potential carcinogen – in the supply chain. However these do eliminate the formaldehyde emission issue.

A legislative issue

No matter how complicated the chemistry gets, formaldehyde is not only a technical issue, but a legislative and even a political one.

From the point of view of regulations, until recently European and US practice has differed significantly. In the US, where no particular piece of regulation was in place to address formaldehyde in wood products, no added formaldehyde or no added urea-formaldehyde was the accepted best practice. Note that this requirement refers to the content of the product and the precautionary principle, “if it’s not been put into the product in the first place, it won’t be a problem”.

In Europe, the EN-717 standard has applied to some wood products, but not all. This specifies a particular formaldehyde emission limit in order for products to be classified as E1. Only products classified as E1 can be sold in EU markets. However, there is no EU-wide limit for emissions from wood products and each Member State is free to set their own limits, as many have already done.

Consequences for certification

This issue has had cascading consequences for projects attempting green building certifications – for example LEED – as the diverse nature of standards and regulations made comparisons and equivalencies very difficult to establish.

With the implementation of California’s emission-based CARB standard into federal law, the United States has gone down the legislative route. This states that beginning 1 June 2018, composite wood products sold, supplied, offered for sale, manufactured, or imported in the United States are required to be labelled as CARB ATCM Phase II or TSCA Title VI compliant.5

However, as the test methods differ from European, products compliant in the US regulatory framework will not necessarily be compliant in Europe and vice versa. Therefore, the problem of comparability across geographic regions remains.

The issue of critical mass

In addition, the additive nature of products in an indoor space is hardly ever considered. In other words, it is possible to have a critical amount (surface area) of products in a room, where each individual product by itself is compliant with the relevant emissions standard, but the resulting overall formaldehyde concentration in the room still exceeds the WHO recommended limit of 0.1 mg/m3.

In a 2016 study, the Danish Environmental Protection Agency showed that typical furniture arrangements in a room, including chairs, bookcases and doors for example can result in higher than recommended formaldehyde concentrations under typical circumstances.6

The impact of air quality

Indoor air quality – and by proxy, health and wellbeing indoors – of course depends greatly on many other factors, which cannot be controlled by product manufacturers. The scope of this article does not extend to a detailed discussion on these, but a few are listed here for further thought.7

  • The air distribution characteristics, ventilation rates and general building services design of a building.
  • Maintenance regimes, regular filter maintenance for instance.
  • The increasingly poor quality of the outdoor air and location of air intakes.
  • Indoor secondary chemistry resulting from other air pollutants from cleaning products, photocopiers, etc.

Any of these factors – especially poor outdoor air quality – have the potential to outweigh any indoor emissions from timber products.

Therefore, although the timber industry can and should drive to reduce emissions from wood products as much as it possibly can to reduce their contribution to indoor air pollution, regulators and industry professionals need to look at the issue in a more systemic and comprehensive way in order to truly tackle the adverse health impacts of poor indoor air quality.

Eszter Gulacsy is the Sustainable Materials leader at Mott MacDonald, where she leads a team of sustainability consultants. In addition, as an organic and analytical chemist, Eszter uses her scientific understanding and over ten years of professional experience to advise developers, owner-occupiers and product suppliers about the chemistry and health implications of construction products and associated trends, emerging regulations and voluntary standards.

Eszter Gulacsy, sustainable materials leader at Mott MacDonald

Footnotes:

The Fraunhofer Institute for Wood Research is a great resource on the technical, scientific and regulatory aspects of formaldehyde emissions from wood products.

1 “Global wellness real estate blossoms into $134b industry.” Guardian. 10th September, 2018.  https://guardian.ng/property/global-wellness-real-estate-blossoms-into-134b-industry/ Accessed: 20th Sept, 2018.

2 American Cancer Society. “Formaldehyde.” https://www.cancer.org/cancer/cancer-causes/formaldehyde.html Accessed: 18th Sept, 2018.

3 Note that formaldehyde is also naturally emitted by some wood species; however, for the purposes of this article, only added formaldehyde is being considered.

4 Healthy Buildings Network. “Alternative Resin Binders for Particleboard, Medium Density Fiberboard (MDF), and Wheatboard.” https://s3.amazonaws.com/hbnweb.dev/uploads/files/alternative-resin-binders-for-particleboard-medium-density-fiberboard-mdf-and-wheatboard.pdf  Accessed: 18th Sept, 2018.

5 US Environmental Protection Agency. Formaldehyde Emission Standards for Composite Wood Products
https://www.epa.gov/formaldehyde/formaldehyde-emission-standards-composite-wood-products Accessed: 18th Sept, 2018.

6 Ministry of Environment and Food of Denmark, Environmental Protection Agency. “Emission of Formaldehyde from Furniture”.  https://www2.mst.dk/Udgiv/publications/2016/01/978-87-93435-12-4.pdf Accessed: 20th Sept, 2018

7 For a critical and scientific review of formaldehyde regulations, see Salthammer, T.  “The formaldehyde dilemma.”.  International Journal of Hygiene and Environmental Health, Volume 218, Issue 4, June 2015, Pages 433-436

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