Skip navigation

Feature article

Formaldehyde: the invisible indoor pollutant

From that familiar fresh paint smell to the unboxing of new furniture – odours associated with these seemingly harmless home improvements are usually an indication that a substance has been released into the air. And while the smell of new paint might fade over time, the emission of potentially harmful gases, such as formaldehyde, can persist. Pollutants like these can continuously ‘off-gas’ for a number of years – but what exactly is formaldehyde and why is it in our homes?

What is formaldehyde and how to remove it from your home

  • Formaldehyde

  • Formaldehyde is a colourless gas pollutant, which can be released by furniture and wooden products containing formaldehyde-based resins, such as plywood and fibreboard, insulating materials, do-it-yourself products such as paint, wallpapers, varnishes and household cleaning products.

    Being 500 times smaller than 0.1 microns, formaldehyde is particularly difficult to capture and left undetected, can be trapped in a home for years.

    Research indicates that the main source of indoor formaldehyde pollution in China comes from the gas being released after decorating a home. If left alone, it has been reported to persist for between three to 15 years due to continuous off-gassing.1

Is exposure to formaldehyde dangerous?

The impact of formaldehyde has been widely reported by the World Health Organisation and other research bodies, with some governmental institutions setting formaldehyde safety limitations and regulating its usage.

While in-home formaldehyde readings at any given time may appear low, potential continuous exposure through off-gassing can sometimes occur over multiple years. This is particularly relevant for homes that have been recently renovated. In a 2019 report, it was found that 50% of Chinese households have indoor formaldehyde concentrations exceeding international and local standards of 0.10mg/m3 2. A different study released in the same year, revealed that in a fifth of the 47 UK homes tested for the pollutant showed more than double the levels deemed safe3. In fact, US authorities such as Centre for Disease Control and Prevention (CDC) claim that there are small amounts of formaldehyde in almost all homes4.

Formaldehyde levels within homes can be exacerbated by how well sealed they are, as a well-sealed home can trap indoor pollutants. This can result in greater exposure over time.

What can you do to reduce formaldehyde within your home?

As well as selecting DIY and renovation products that don’t contain formaldehyde, increasing ventilation and using purification within a space can help to remove the gas from your home.

Dyson’s Purifier Cool Formaldehyde TP09 and Dyson's Purifier Big+Quiet Formaldehyde for example, not only sense formaldehyde with their intelligent solid-state sensor, but also destroy it, using Dyson’s Selective Catalytic Oxidisation (SCO) filter.


Some formaldehyde sensors are gel-based, so can dry out over time, causing the precision and performance of the sensor to deteriorate. Dyson’s formaldehyde sensor is solid-state, and so doesn’t dry out, lasting the lifetime of the machine. Its intelligent algorithm precisely senses formaldehyde levels without confusing it with other VOCs.


As well as sensing formaldehyde, Dyson’s SCO filter captures and destroys the pollutant at a molecular level, breaking it down into tiny amounts of water and CO2. It then regenerates from the oxygen in the air to keep destroying it continuously without ever requiring replacement.

  • Formaldehyde levels detected by the Dyson Purifier Cool and the Dyson Purifier Big+Quiet Formaldehyde are reported via the LCD screen and the MyDyson app. This helps to reassure the user that the invisible pollutant is being captured and destroyed, supporting a healthier indoor space.

  • Formaldehyde

[1] Chinese Home Indoor Formaldehyde White Paper, CHEARI, 2019.
[2] Chinese Home Indoor Formaldehyde White Paper, CHEARI, 2019.
[3] Airtopia, Clean Air Day, 2019.
[4] Formaldehyde in your home- what you need to know, Centre for Disease Control and Prevention.

Dyson Newsroom

The latest news from Dyson