Indoor Air Pollutant Checklist for New Home Construction Projects

Indoor Air Pollutant Checklist for New Home Construction Projects

By Ruth MacEachern

Product Manager

What designers and developers should be aware of in minimising the concentrations of Indoor Air Pollutants to reduce the impact on health.

Indoor air quality is a very important indicator for maintaining the comfort and health of an enclosed space, whether it is used for living or any other purpose. In order to maintain adequate standards, it is necessary to have the tools and regulations in place to monitor indoor air quality.

In this article we would like to discuss the main air pollutants and provide a checklist to help to reduce their presence in the environment.

Why is it important to monitor the IAQ of indoor spaces?  

On average there are around 250,000 new homes built across the UK every year. As our homes are being built to increasing levels of airtightness and thermal efficiency, the importance of understanding the effects of indoor air quality and the sources of indoor air pollutants as a result of the construction products specified for new homes is imperative.

The health impacts of indoor air pollutants are wide ranging, one of which is Asthma. Asthma is an increasingly common respiratory condition that affects up to 30 percent of children and 10 percent of adults. Exposure to certain chemicals, such as formaldehyde and phthalates found in construction materials, has been associated with increased risk of asthma, allergies and pulmonary infections. Therefore, the quality of indoor air is of vital importance to health, especially when people today spend up to 90 percent of their time indoors and the concentration of contaminants can be 100 to 1,000 times higher indoors than outside.

Main air pollutants and how to reduce them. 

To assist in reducing the impact of indoor air pollution, it is important to understand sources of the major pollutants, which are predominantly Volatile Organic Compounds (VOCs) and formaldehyde within building materials, which can be emitted into indoor air. Research has identified that organic emissions vary between buildings and building materials. In new buildings and new construction materials, VOC emissions vary from 0.5 to 19 mg/m3. In old buildings, on the other hand, levels range between 0.2 and 1.7 mg/m3.

Sources of VOCs include

• Flooring
• Composite wood products
• Adhesives. Adhesives used during flooring installation, for example, can represent a significant source of VOC emissions into the air.

Sources of formaldehyde include:

• Paints and varnishes
• Certain insulation materials
• Manufactured wood and pressed products such as plywood

Other sources of Indoor Air Pollutants can be found in our blog The Most Common Pollutants in Your Home

How to reduce Indoor Air Pollution?

Here is a useful checklist taken from the NICE guidelines Indoor Air Quality At Home [NG149] (Published: 08 January 2020) for designers and developers to consider when specifying construction products:

• Consider specifying building materials and products that only emit a low level of formaldehyde and VOCs. Use existing labelling schemes or other available information on product emissions (for example, on product labels) to make these specifications.
• Design or specify heating systems that minimise indoor exposure to particulate matter.
• Adopt a whole-building approach to heating and ventilation to ensure indoor air quality is maintained while achieving standards for energy use.
• Ensure design strategies include provision for removing indoor air pollutants, for example by:
  • Specifying kitchen extractor fans or cooker hoods that extract to the outside, and are easily accessible for cleaning or maintenance, with simple instructions for residents
  • Design ventilation systems to reduce or avoid exposure to outdoor air pollution. For example:
    • Ensure windows that open face away from sources of outdoor air pollution, such as busy roads,
    • Fit mechanical systems with filtration to protect against outdoor pollutants.

What are the filters in a ventilation system for?

Ventilation products, particularly MVHR systems can be supplied with various levels of filtration to reduce the impact on indoor air pollution. In the table below, the various grades of filters are outlined, which shows which type of particulate each grade can be used for. 

As shown, VOCs and pollutant gases can be filtered with a carbon filter. However, there is also a growing concern around air pollution in our cities and urban areas where high levels of Nitrogen Dioxide can enter the home. This has driven a demand to implement necessary mitigation measures to improve our indoor air quality (IAQ). The EnviroVent NitroBox NO² filter is an effective means of reducing high Nitrogen Dioxide (NO²) levels from entering the home. In addition to reducing NO² levels, NitroBox’s active carbon filters also absorb Sulphur Dioxide (SO2), Hydrogen Sulphide (H2S), Hydrogen Chloride (HCI), Ammonia (NH3), Volatile Organic Compounds (VOC) and other common solvents. It can be used with a number of MVHR systems.

Professional indoor air quality testing may be required in areas that are particularly affected by high levels of NO2 and outdoor air pollution, where a specialist consultant will be able to advise on the remedial measures and ventilation strategy to reduce indoor pollutants. 

In summary, it is vitally important that when dwellings are being built or refurbished to improve thermal performance, that there is permanent, effective ventilation in order to reduce the impact of indoor air pollutants on our health.