Indoor air quality (IAQ) has become a crucial consideration in modern building design as people spend more time indoors, making the air we breathe inside buildings critical to our health.
This is made worse in tropical urban environments, where residents are inclined to be totally enclosed in their homes (and offices), relying on air conditioning to keep cool, adding to their exposure to chemicals and gases.
One major concern affecting IAQ is the presence of formaldehyde, a volatile organic compound (VOC) commonly used in building materials. In August, the Singapore Parliament was told that authorities are “reviewing the use of formaldehyde in products such as furniture and adhesives”.
This followed recent media reports of people here falling ill due to high formaldehyde levels in their furnishings, with Channel News Asia (CNA) reporting that one family paid S$1,000 for treatments to their wooden cabinets and shelves after their young children repeatedly fell sick due to high levels of the chemical.
As the Straits Times reported at the time:
“Often found in resins and glues used in wooden furniture – as well as in composite wood products such as plywood and fibreboard – formaldehyde can cause irritation of the eyes, nose and throat, with long-term exposure linked to certain cancers.”
Earlier in 2024, it was announced that Singapore would ban formaldehyde in paint used for the interiors of buildings from January 2026.
I asked three people I know who are familiar with buildings and glues what they think must be done to address the serious health issues of formaldehyde.
This is from Chethiya Ratnakara – a veteran Mass Timber construction specialist with over 18 years of industry experience who’s led several iconic timber projects in Singapore and globally, including the Jurong Lake Gardens project reported in Wood Central.
He is a regular speaker on MET-related topics, particularly fire compliance, sustainability, and productivity. Previously with Venturer Timberworks, now he is the Managing Director of Versobuild, a Singaporean company that provides services globally in mass timber and hybrid construction.
He is actively working on several projects in the Middle East for star resort developments and regionally on high-rise timber buildings, data centres, and long-span timber roofs using timber.
Chethiya admits that Mass-Engineered Timber (MET), along with Glued-Laminated Timber (GLT) and Cross-Laminated Timber (CLT), can sometimes contribute to formaldehyde emissions due to the adhesives used in their production during the timber lamination process. He explains that formaldehyde is a colourless gas with an odour known for its widespread use in adhesives and resins. Both short and long-term exposure to formaldehyde can pose serious health risks such as:
- Short-term exposure can cause irritation of the eyes, nose, and throat, as well as headaches and dizziness.
- Long-term exposure has been linked to more severe conditions, including chronic respiratory problems and even certain types of cancer.
Formaldehyde in MET Products
Chehtiya agrees that while MET is valued for its structural strength, sustainability, and aesthetic appeal, the glues and adhesives that bind these wood layers together may contain formaldehyde.
Common types of formaldehyde-based adhesives include urea-formaldehyde and phenol-formaldehyde, which can release harmful emissions into the air. While phenol-formaldehyde generally releases lower levels of formaldehyde over time, urea-formaldehyde is a more concerning source of emissions.
How can we Reduce the Risk?
Fortunately, the industry has made strides in reducing formaldehyde emissions, says Chethiya, who has worked with MET, CLT and GLT for many years:
“Some modern timber manufacturers nowadays use VOC-free and formaldehyde-free PUR adhesives in accordance with European Standards. The adhesives have been tested and classified as accordingly and have been approved for the production of load-bearing timber components. This is a significant milestone to the timber industry and its gaining popularity of using these adhesives to avoid VOC.”
“Many manufacturers now use formaldehyde-free adhesives, such as polyurethane or PVA (polyvinyl acetate), to meet stricter health and environmental standards.”
“Certified low-emission products—including those that comply with EPA TSCA Title VI or CARBregulations—are available to ensure safer indoor environments”.
Chethiya also referred us to KLH – one of the world’s biggest producers of CLT, who had this to say on adhesives:
Only VOC-free and formaldehyde-free PUR adhesives are used in accordance with EN 15425. The adhesives have been tested and classified as TYPE 1 adhesives and have been approved for the production of load-bearing timber components.
The adhesive is applied automatically over the entire surface approx. 0.15 kg/m² per joint. The laminated pressure at 0.6 N/mm² used during the manufacturing of KLH® solid timber panels is six times higher when compared with vacuum press technology. The quality of the lamination of KLH® CLT is therefore of high quality and the load-bearing capacity comparatively higher.
I also talked to my friend Nicola Greenaway, founding partner and managing director of NIKAU Design Group, an experienced leader with a demonstrated history of working in the design industry, with 20 years of experience working across Europe and the Asia Pacific region.
She has spent three years based in Singapore and Macau, with travel to Las Vegas as a Regional Director specialising in master planning, design, and delivery of integrated resorts, hotels, casinos, gaming floors, F&B, entertainment, and leisure projects.
Taking a broader approach to the business of indoor air quality, Nicola points to recent research in the UK backed by the Design Council, which reveals that thoughtful design is key to making repairability a reality and, therefore, more sustainable for reuse purposes.
Using screws instead of adhesives
She notes that the findings highlighted the importance of international design choices, such as durable materials, using screws instead of adhesives, and providing clear user guides for all projects:
It is NIKAU Design Group’s role as designers and project managers to further harness the right regulatory framework and incentives to support brands to adopt repair principles successfully.
Our approach to product design will shape a more sustainable future to champion products built for longevity and ease of repair.
We are fostering a culture for our children of reuse, and reducing our environmental footprint.
Respect for our origins and the environment is at the very heart of NIKAU. We want to contribute to a more sustainable future in harmony with our environment.
To achieve this, we invest in the human factor and resources, working hand-in-hand with local suppliers to source the materials with the lowest environmental impact while achieving the design and styling of projects that define NIKAU Design Group.
So, Nicola Greenaway, as a building design specialist, clearly advocates doing away with any products, like harmful glues, if they are not conducive to the health of people, buildings or the environment at large.
I also asked James Tan of the Singapore Green Building Council for his take on the dangerous health effects of formaldehyde, noting recent media reports in Singapore and elsewhere.
James oversees partnerships and collaborations, heads corporate communications and leads the delivery of events for the SGBC. He has spent a decade engaging with every type of organisation across the building and construction value chain to advance built environment sustainability goals.
James told me that SGBC did some work to address formaldehyde through an alliance for action in 2022-2023, which culminated in a set of indoor air quality guidelines for the industry. These can be found here:
He also gave me a copy of the full report from the Alliance for Action on Sustainable Space – Industry Guidelines for Indoor Air Quality.
Among other things, it points to the serious issue with formaldehyde:
Formaldehyde is an indoor air pollutant that is common in Singapore. It is a pungent, colourless and flammable VOC that is commonly found in building materials and household furnishings and can be hazardous to human health if high-level exposure occurs.
Being 500 times smaller than 0.1 microns, formaldehyde is particularly difficult to capture and, if left undetected, can be trapped in a space for years. Short-term exposure to formaldehyde can cause dry/ watery eyes, headaches, induce nausea, cause coughs, breathlessness, lethargy, insomnia and respiratory ailments, while prolonged exposure can lead to damage to the liver, lungs, kidneys, and central nervous system and increase the risk of contracting cancer.
Formaldehyde levels in indoor spaces are particularly high during and after a renovation due to the use of adhesives, paints, and new building materials.
According to the World Health Organization (WHO), an indoor environment with more than 0.1 mg/m3 of formaldehyde is considered toxic and is congruent with the Singapore Standards for indoor air quality (SS554). It is, therefore, essential to ensure that formaldehyde levels are kept to the absolute minimum within our places and spaces.
From my three (or more) sources of information and comment, there’s a very “clear and present danger” with formaldehyde and we are best to get rid of this pollutant, which is not good for the health of our people, buildings, furniture or the planet at large.
Let’s give the last word to Chethiya Ratnakara, the veteran Mass Timber construction specialist, who provides us with this very useful conclusion:
For those concerned about IAQ when using MET, several steps can be taken:
- Choose formaldehyde-free MET products: Look for certifications ensuring low or zero formaldehyde emissions by using certified PUR adhesives rated in accordance with European Standards.
- Increase ventilation: Proper ventilation systems can help reduce the concentration of formaldehyde and other VOCs indoors.
- Seal surfaces: Applying low-VOC sealants to MET surfaces can reduce the release of formaldehyde.
Chethiya concludes: “While formaldehyde in MET products can affect indoor air quality, advancements in adhesive technology and material certifications are helping to make these products safer for occupants.”
“Ensuring the use of low-emission materials and implementing good ventilation practices can significantly reduce the risks posed by formaldehyde and improve the overall indoor air environment. There are also solutions and surface applications that can be done onsite after installation to reduce the impact of VOC levels”.
